2006, 有機電気化学研究会奨励賞　　　　　　　　　　　　　　　
Japan

2004, 日本化学会北海道支部奨励賞　　　　　　　　　　　　　　　
Japan

2004, Award for Young Chemist, Hokkaido Branch of The Chemical Society of Japan　　　　　　　　　　　　　　　

Efficient one-step synthesis of diarylacetic acids by electrochemical direct carboxylation of diarylmethanol compounds in DMSO
Hisanori Senboku, Mizuki Hayama
Beilstein Journal of Organic Chemistry, 20 Sep. 2024
Scientific journal

Cyclo[4]pyrrole with α–β direct linkages
Yuhua Sun, Riku Kitahara, Tomoya Ichino, Yuki Ide, Hisanori Senboku, Soji Shimizu, Takayuki Tanaka, Yasuhide Inokuma
Chemical Science, 2024
Scientific journal

Synthesis of Carboxylic Acid by Electrochemical Fixation of Carbon Dioxide: A Review of Electrochemical Carboxylation from Past to Latest
Hisanori Senboku
Current Organic Chemistry, 28, 2, 76, 88, Jan. 2024, [Peer-reviewed]
Scientific journal

N-methyldiethanolamine (MDEA) as an effective CO2 absorbent for direct air capture (DAC) in cement-based materials
Kirushnapillai Kopitha, Elakneswaran Yogarajah, Ryoma Kitagaki, Ryosuke Saito, Masato Tsujino, Akira Nishida, Hisanori Senboku, Naoki Hiroyoshi
Chemical Engineering Journal, Nov. 2023
English, Scientific journal

Direct Substitution of a Hydroxyl Group by a Carboxyl Group at the Benzylic Position in Benzyl Alcohols by Electrochemical Reduction in the Presence of Carbon Dioxide: Improvement Enabling Electrochemical Direct Carboxylation of Benzyl Alcohols even in the Absence of an Electron-withdrawing Group on the Phenyl Ring
Mizuki HAYAMA, Hisanori SENBOKU
Electrochemistry, 91, 11, 112011, 23 Sep. 2023, [Peer-reviewed], [Invited], [Last author, Corresponding author]
Scientific journal

Electrochemical Friedel–Crafts-type amidomethylation of arenes by a novel electrochemical oxidation system using a quasi-divided cell and trialkylammonium tetrafluoroborate
Hisanori Senboku, Mizuki Hayama, Hidetoshi Matsuno
Beilstein Journal of Organic Chemistry, 18, 1040, 1046, 18 Aug. 2022, [Peer-reviewed], [Invited], [Lead author, Corresponding author]
Scientific journal

Synthesis of N-Boc-α-amino Acids from Carbon Dioxide by Electrochemical Carboxylation of N-Boc-α-aminosulfones
Hisanori Senboku, Yoshihito Minemura, Yuto Suzuki, Hidetoshi Matsuno, Mayu Takakuwa
The Journal of Organic Chemistry, 86, 22, 16077, 16083, American Chemical Society ({ACS}), 22 Sep. 2021, [Peer-reviewed], [Invited], [Lead author, Corresponding author]
Scientific journal

Electrochemical Fixation of Carbon Dioxide: Synthesis of Carboxylic Acids
H. Senboku
The Chemical Record, 21, 9, 2354, 2374, Wiley, Sep. 2021, [Peer-reviewed], [Lead author, Corresponding author]
Scientific journal

Integrated Flow Synthesis of α-Amino Acids by In Situ Generation of Aldimines and Subsequent Electrochemical Carboxylation
Yuki Naito, Yuto Nakamura, Naoki Shida, Hisanori Senboku, Kenta Tanaka, Mahito Atobe
The Journal of Organic Chemistry, 86, 22, 15953, 15960, American Chemical Society (ACS), 21 Jun. 2021, [Peer-reviewed]
Scientific journal

Synthesis of indolo[2,1‐a]isoquinolines by CF3COOH‐induced cyclization
Yasuhiro Wada, Nobuhito Kurono, Hisanori Senboku, Kazuhiko Orito
Journal of Heterocyclic Chemistry, 57, 10, 3703, 3708, Wiley, Oct. 2020, [Peer-reviewed]
English, Scientific journal, Indolo[2,1-a]isoquinoline alkaloids and related compounds have been known to have interesting biological activities, such as antileukemic and antitumor activities. We found that 1-(3,4-dimethoxyphenethyl)indole gave 2,3-dimethoxyindolo[2,1-a]isoquinoline and 1-(3,4-dimethoxyphenylacetyl)indole gave 2,3-dimethoxy-6-oxoindolo[2,1-a]isoquinoline, respectively, by an intramolecular cyclization carried out in boiling trifluoroacetic acid.

Efficient Synthesis of Mandel Acetates by Electrochemical Carboxylation of Benzal Diacetates
Senboku Hisanori, Sakai Kanae, Fukui Akihiro, Sato Yusuke, Yamauchi Yusuke
ChemElectroChem (IF: 3.975), 5, 16, 4158, 4164, Wiley, Mar. 2019, [Peer-reviewed]
English, Scientific journal

Bioinspired synthesis of pentalene-based chromophores from an oligoketone chain
Yuki Saito, Masayuki Higuchi, Shota Yoshioka, Hisanori Senboku, Yasuhide Inokuma
Chemical Communications, 54, 50, 6788, 6791, Royal Society of Chemistry, 2018, [Peer-reviewed]
English, Scientific journal, We report a bioinspired synthesis of 2,5-dihydropentalene-based chromophores from an aliphatic oligoketone bearing 1,3- and 1,4-diketone subunits. Unlike the natural polyketone sequence, fused five-membered rings were formed via an intramolecular aldol condensation. A subsequent Knoevenagel condensation reaction with malononitrile furnished a multiply cross-conjugated π-system with low-lying LUMO levels. Furthermore, pentalenes obtained from a non-conjugated aliphatic chain exhibited visible absorption and solid-state fluorescence.

Electrochemical carboxylation with carbon dioxide
Hisanori Senboku, Asahi Katayama
Current Opinion in Green and Sustainable Chemistry, 3, 50, 54, Elsevier B.V., 01 Feb. 2017, [Peer-reviewed]
English, Studies carried out in the past two years on electrochemical fixation of carbon dioxide with carbon-carbon bond formation, so-called electrochemical carboxylation or electrocarboxylation, are reviewed. Among about twenty papers on electrochemical carboxylation published from 2014 to the present, recent advances in electrochemical carboxylation regarding asymmetric carboxylation, sacrificial anode-free carboxylation, and carboxylation following aryl radical cyclization are focused on and discussed.

Sequential Vinyl Radical Cyclization/Fixation of Carbon Dioxide through Electrochemical Reduction of Vinyl Bromide in the Presence of an Electron-Transfer Mediator
Asahi Katayama, Hisanori Senboku
CHEMELECTROCHEM, 3, 12, 2052, 2057, WILEY-V C H VERLAG GMBH, Dec. 2016, [Peer-reviewed]
English, Scientific journal, Constant-current electrolysis of vinyl bromide in DMF containing 0.1m Bu4NBF4 by using an undivided cell equipped with a platinum plate cathode and a magnesium rod anode in the presence of an electron-transfer mediator, methyl 4-tert-butylbenzoate, and carbon dioxide resulted in selective generation of a vinyl radical, for which cyclization followed by fixation of carbon dioxide with a carbon-carbon bond formation gave ,-unsaturated carbo- and heterocycle carboxylic acids in moderate to good yields. The vinyl radical could be selectively generated under the electrolysis conditions, and the following reaction of the anion species, generated by one-electron reduction of the resulting cyclized radical, with carbon dioxide took place efficiently. These results and cyclic voltammetry indicate that methyl 4-tert-butylbenzoate plays an important role in the generation of vinyl radicals from vinyl bromides. The resulting cyclized ,-unsaturated carboxylic acid was successfully applied to stepwise and direct iodo-lactonization to give the corresponding bicycle -lactones in good yields.

Aryl radical cyclization with alkyne followed by tandem carboxylation in methyl 4-tert-butylbenzoate-mediated electrochemical reduction of 2-(2-propynyloxy)bromobenzenes in the presence of carbon dioxide
Asahi Katayama, Hisanori Senboku, Shoji Hara
TETRAHEDRON, 72, 31, 4626, 4636, PERGAMON-ELSEVIER SCIENCE LTD, Aug. 2016, [Peer-reviewed]
English, Scientific journal, Constant current electrolysis of 2-(2-propynyloxy)bromobenzenes in DMF using an undivided cell equipped with a Pt cathode and an Mg anode in the presence of carbon dioxide and an electron transfer mediator, methyl 4-tert-butylbenzoate, resulted in aryl radical cyclization with a carbon carbon triple bond followed by fixation of two molecules of carbon dioxide to give 2,2-ring-fused succinic acid derivatives in moderate to good yields. Dihydrobenzofuran, indoline, dihydrobenzothiophene, and indane as well as tetrahydropyran skeletons were successfully constructed by aryl radical cyclization, and unique tandem carboxylation successively occurred to produce succinic acids. One of the resulting succinic acid derivatives, 3-carboxy-2,3-dihydrobenzofuran-3-ylacetic acid, was successfully applied to the synthesis of a novel spiro compound consisting of 2,3-dihydrobenzofuran and gamma-butyrolactone at each C3 position in two steps in high yield. (C) 2016 Elsevier Ltd. All rights reserved.

Electrochemical direct carboxylation of benzyl alcohols having an electron-withdrawing group on the phenyl ring: one-step formation of phenylacetic acids from benzyl alcohols under mild conditions
Hisanori Senboku, Kenji Yoneda, Shoji Hara
TETRAHEDRON LETTERS, 56, 48, 6772, 6776, PERGAMON-ELSEVIER SCIENCE LTD, Dec. 2015, [Peer-reviewed]
English, Scientific journal, Electrochemical direct carboxylation of benzyl alcohols having an electron-withdrawing group on the phenyl ring was successfully carried out by constant current electrolysis using an undivided cell equipped with a platinum plate cathode and a magnesium rod anode in DMF in the presence of carbon dioxide. Reductive cleavage of the C-O bond followed by fixation of carbon dioxide efficiently took place at the benzylic position without any additive to give the corresponding phenylacetic acids in good yields in one step under neutral and mild conditions. (C) 2015 Elsevier Ltd. All rights reserved.

Three-component coupling reaction of benzylic halides, carbon dioxide, and N,N-dimethylformamide by using paired electrolysis: sacrificial anode-free efficient electrochemical carboxylation of benzylic halides
Hisanori Senboku, Kotaro Nagakura, Tsuyoshi Fukuhara, Shoji Hara
TETRAHEDRON, 71, 23, 3850, 3856, PERGAMON-ELSEVIER SCIENCE LTD, Jun. 2015, [Peer-reviewed]
English, Scientific journal, Sacrificial anode-free efficient electrochemical carboxylation of benzylic halides was successfully performed by using a paired electrolysis protocol. Constant-current electrolysis of a DMF solution of benzylic halides in the presence of carbon dioxide using a one-compartment cell equipped with a Pt plate cathode and a Pt wire anode (quasi-divided cell) resulted in efficient three-component coupling reaction of benzylic halides, carbon dioxide and DMF to yield N-methyl-N-(phenylacetoxy)methylformamides, as carboxylated coupling products, in good yields. (C) 2015 Elsevier Ltd. All rights reserved.

Electrochemical fixation of CO2 to organohalides in room-temperature ionic liquids under supercritical CO2
Hiroyuki Tateno, Koji Nakabayashi, Tsuneo Kashiwagi, Hisanori Senboku, Mahito Atobe
ELECTROCHIMICA ACTA, 161, 212, 218, PERGAMON-ELSEVIER SCIENCE LTD, Apr. 2015, [Peer-reviewed]
English, Scientific journal, The electrochemical properties of novel reaction media, ionic liquid (IL)/supercritical CO2 (scCO(2)) systems, were evaluated and the electrochemical carboxylation of various organohalides in these systems was demonstrated. Voltammetric studies revealed that the CO2 solubility in an IL such as N, N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis(trifluoromethanesulfonyl) imide ([DEME] [TFSI]) increased in the presence of scCO(2). The IL/scCO(2) systems were found to be effective for the electrochemical carboxylation of various organohalides. (C) 2015 Elsevier Ltd. All rights reserved.

Development of a novel electrochemical carboxylation system using a microreactor
Hiroyuki Tateno, Yoshimasa Matsumura, Koji Nakabayashi, Hisanori Senboku, Mahito Atobe
RSC ADVANCES, 5, 119, 98721, 98723, ROYAL SOC CHEMISTRY, 2015
English, Scientific journal, We have developed a novel electrochemical carboxylation system for CO2 fixation to benzyl halides using a microreactor. In this system, electrochemical carboxylation of benzyl halides proceeded very efficiently without the use of a sacrificial anode such as a Mg anode to give carboxylated products in excellent yields.

Regioselective electrochemical carboxylation of polyfluoroarenes
Hisanori Senboku, Kenji Yoneda, Shoji Hara
Electrochemistry, 81, 5, 380, 382, May 2013
English, Scientific journal, Constant current electrolysis of polyfluoroarenes in DMF containing 0.1 moldm-3 Bu4NBF4 in the presence of carbon dioxide by using a one-compartment cell equipped with a Pt cathode and a Mg anode at -40°C resulted in reductive cleavage of a C-F bond of the phenyl ring followed by reaction with carbon dioxide in highly regio- and chemoselective manners to give the corresponding mono-carboxylated products, polyfluorobenzoic acids, in moderate to good yields.

Synthesis of 8-Oxoberbines and Related Benzolactams by Pd(OAc)2-Catalyzed Direct Aromatic Carbonylation
Mamoru Miyazawa, Takashi Tokuhashi, Akiyoshi Horibata, Takatoshi Nakamura, Yu Onozaki, Nobuhito Kurono, Hisanori Senboku, Masao Tokuda, Takeshi Ohkuma, Kazuhiko Orito
JOURNAL OF HETEROCYCLIC CHEMISTRY, 50, E48, E54, WILEY-BLACKWELL, Feb. 2013
English, Scientific journal, A variety of alkoxy-substituted benzolactams with a berbine or yohimbane skeleton were prepared from 1-benzyl-1,2,3,4-tetrahydroisoquinolines or 1-benzyl-1,2,3,4-tetrahydro-beta-carbolines by a phosphine-free Pd(II)-catalyzed direct aromatic carbonylation in a Pd(OAc)(2)-Cu(OAc)(2) catalytic system. The site selectivity was compared with that of the carbonylation with Pd(OAc)(2) or Pd(OAc)(2)center dot 2 PPh3, respectively.

Some mechanistic studies on electrochemical carboxylation of flavones to yield flavanone-2-carboxylic acids
Hisanori Senboku, Yusuke Yamauchi, Natsuko Kobayashi, Akihiro Fukui, Shoji Hara
ELECTROCHIMICA ACTA, 82, 450, 456, PERGAMON-ELSEVIER SCIENCE LTD, Nov. 2012, [Peer-reviewed]
English, Scientific journal, Electrochemical carboxylation of flavones was successfully demonstrated. Constant current electrolysis of a DMF solution of flavones containing 0.1 M Bu4NBF4 in the presence of carbon dioxide by using a one-compartment cell equipped with a Pt cathode and an Mg anode at 0 degrees C resulted in fixation of carbon dioxide at the C2-position of flavones in a highly regioselective manner to give flavanone-2-carboxylic acids in moderate to good yields. From the results of some mechanistic examinations, we could conclude that flavanone-2-carboxylic acids were produced through exclusive mono-carboxylation of flavones at the C2-position and that dicarboxylation both at the C2- and C3-positions of flavones hardly proceeded. We report herein details of the electrochemical carboxylation of flavones to obtain flavanone-2-carboxylic acids, and we propose a reaction mechanism for the C2-selective carboxylation. (C) 2012 Elsevier Ltd. All rights reserved.

Synthesis of Benzo[c]phenanthridine Alkaloids by Pd(OAc)2-Induced Direct Aromatic Carbonylation
Eri Kumazawa, Takashi Tokuhashi, Akiyoshi Horibata, Nobuhito Kurono, Hisanori Senboku, Masao Tokuda, Takashi Ohkuma, Kazuhiko Orito
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, 2012, 24, 4622, 4633, WILEY-V C H VERLAG GMBH, Aug. 2012, [Peer-reviewed]
English, Scientific journal, The Pd(OAc)2-induced carbonylation of alkoxy-substituted 1-amino-2-phenyltetralins and 1-amino-2-phenylnaphthalenes was examined to provide the benzo[c]phenanthridine ring system. The carbonylation of substrates containing methylenedioxy groups gave oxysanguinarine and oxyavicine. The tetramethoxy derivatives gave O-methyloxyfagaronine. The substrate with a benzyloxy group afforded a known synthetic precursor to the antileukemic alkaloid, fagaronine.

Phosphane-Free Pd-0-Catalyzed Cycloamination and Carbonylation with Pd(OAc)(2) and Cu(OAc)(2) in the Presence of K2CO3: Preparation of Benzocyclic Amines and Benzolactams
Rika Harada, Naoto Nishida, Shiho Uchiito, Yu Onozaki, Nobuhito Kurono, Hisanori Senboku, Tokuda Masao, Takeshi Ohkuma, Kazuhiko Orito
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, 2012, 2, 366, 379, WILEY-V C H VERLAG GMBH, Jan. 2012, [Peer-reviewed]
English, Scientific journal, Phosphane-free Pd-0-catalyzed intramolecular aromatic amination was studied. o-Halophenethylamines and 3-(o-halophenyl)propylamines were found to be transformed into indolines and quinolines in a catalytic system based on Pd(OAc)(2) and Cu(OAc)(2) in the presence of K2CO3. Application of the method to substrates containing isoquinoline rings - the 1-(o-bromobenzyl)-3,4-dihydroisoquinolines 6, the 1-(o-bromobenzyl)-1,2,3,4-tetrahydroisoquinolines 7, and the 1-(o-bromophenethyl)isoquinolines 9 - provided the indolo[2,1-a] isoquinoline and dibenzo[a,f] quinolizine ring systems 8 and 10. Extension of the method to beta-carbolines (compounds 11, 12, and 17) produced the benz[f] indolo[2,3-a]indolizine-13-ones 15 and the benz[f] indolo[2,3-a] quinolizine 18. The benzo[f] pyrido[3,4-a] indolizine and indolo[f] pyrido[ 3,4-a]indolizin-12-one ring systems 27 and 31 were built in a similar manner. It was also found that under an atmosphere of CO the same catalytic system produced the corresponding benzolactams, the isoquino[2,1-a][2,7] naphthyridine 34 and the indolo[2,3-a] pyrido[g]quinolizin-8-one 36 [ (+/-)-dihydronauclefine] in good yields.

Electrochemical Carboxylation of Flavones: Facile Synthesis of Flavanone-2-carboxylic Acids
Hisanori Senboku, Yusuke Yamauchi, Natsuko Kobayashi, Akihiro Fukui, Shoji Hara
ELECTROCHEMISTRY, 79, 11, 862, 864, ELECTROCHEMICAL SOC JAPAN, Nov. 2011, [Peer-reviewed]
English, Scientific journal, Constant current electrolysis of flavones in DMF containing 0.1 mol dm(-3) Bu4NBF4 in the presence of CO2 by using a one-compartment cell equipped with a Pt cathode and an Mg anode resulted in reductive carboxylation at the C-2 position of flavones in a highly regioselective manner to give flavanone-2-carboxylic acids in moderate to good yields.

Facile Synthesis of 2,3-Dihydrobenzofuran-3-ylacetic Acids by Novel Electrochemical Sequential Aryl Radical Cyclization-Carboxylation of 2-Allyloxybromobenzenes Using Methyl 4-tert-Butylbenzoate as an Electron-Transfer Mediator
Hisanori Senboku, Jun-ya Michinishi, Shoji Hara
SYNLETT, 2011, 11, 1567, 1572, GEORG THIEME VERLAG KG, Jul. 2011, [Peer-reviewed]
English, Scientific journal, Facile synthesis of 2,3-dihydrobenzofuran-3-ylacetic acids and related analogues was successfully carried out by a novel electrochemical aryl radical generation and its 5-exo cyclization followed by a carboxylation sequence of 2-allyloxybromobenzenes by using methyl 4-tert-butylbenzoate as an electron-transfer mediator.

Electrochemical carboxylation of benzylic carbonates: alternative method for efficient synthesis of arylacetic acids
Masashi Ohkoshi, Jun-Ya Michinishi, Shoji Hara, Hisanori Senboku
TETRAHEDRON, 66, 39, 7732, 7737, PERGAMON-ELSEVIER SCIENCE LTD, Sep. 2010, [Peer-reviewed]
English, Scientific journal, Electrochemical carboxylation of benzylic carbonates was successfully performed as an alternative method for the synthesis of phenylacetic acids by using a one-compartment cell equipped with a Pt plate cathode and an Mg rod anode in CH(3)CN to afford the corresponding phenylacetic acids in good yields. (C) 2010 Elsevier Ltd. All rights reserved.

Electrochemical carboxylation of alpha-chloroethylbenzene in ionic liquids compressed with carbon dioxide
Yusuke Hiejima, Masahiro Hayashi, Akihiro Uda, Seiko Oya, Hiroyuki Kondo, Hisanori Senboku, Kenji Takahashi
PHYSICAL CHEMISTRY CHEMICAL PHYSICS, 12, 8, 1953, 1957, ROYAL SOC CHEMISTRY, 2010, [Peer-reviewed]
English, Scientific journal, Electrochemical carboxylation is conducted in ionic liquids compressed with carbon dioxide. It is found that the current efficiency increases with temperature and pressure. The diffusion coefficient of the substrate, which is obtained from the electrochemical measurements, also remarkably increases with temperature and pressure. The increase of the current efficiency is mainly explained by improvement in the mass transfer, and the promotion of the electrochemical carboxylation in the ionic liquid is achieved by pressurizing the carbon dioxide moderately.

Synthesis of 2-aryl-3,3,3-trifluoropropanoic acids using electrochemical carboxylation of (1-bromo-2,2,2-trifluoroethyl)arenes and its application to the synthesis of beta,beta,beta-trifluorinated non-steroidal anti-inflammatory drugs
Yusuke Yamauchi, Shoji Hara, Hisanori Senboku
TETRAHEDRON, 66, 2, 473, 479, PERGAMON-ELSEVIER SCIENCE LTD, Jan. 2010, [Peer-reviewed]
English, Scientific journal, Electrochemical carboxylation of (1-bromo-2,2,2-trifluoroethyl)arenes resulted in an efficient fixation of carbon dioxide to give the corresponding 2-aryl-3,3,3-trifluoropropanoic acids in good yields, and the present reactions were successfully applied to the synthesis of beta,beta,beta-trifluorinated non-steroidal anti-inflammatory drugs (NSAIDs). (C) 2009 Elsevier Ltd. All rights reserved.

Hg cathode-free electrochemical detosylation of N,N-disubstituted p-toluenesulfonamides: mild, efficient, and selective removal of N-tosyl group
Hisanori Senboku, Kazuo Nakahara, Tsuyoshi Fukuhara, Shoji Hara
TETRAHEDRON LETTERS, 51, 2, 435, 438, PERGAMON-ELSEVIER SCIENCE LTD, Jan. 2010, [Peer-reviewed]
English, Scientific journal, Hg cathode-free electrochemical detosylation of N,N-disubstituted p-toluenesulfonamides was successfully carried out by a constant Current electrolysis using an undivided cell equipped with a platinum cathode and a magnesium anode in the presence of an arene mediator. The deprotection proceeded efficiently and selectively under neutral and mild conditions with a stoichiometric amount of electricity without the use of an Hg cathode to obtain the corresponding secondary amines in good to excellent yields. (C) 2009 Elsevier Ltd. All rights reserved.

Synthesis of 2-Aryl-2,3,3,3-tetrafluoropropanoic Acids, Tetrafluorinated Fenoprofen and Ketoprofen by Electrochemical Carboxylation of Pentafluoroethylarenes
Yusuke Yamauchi, Kanae Sakai, Tsuyoshi Fukuhara, Shoji Hara, Hisanori Senboku
SYNTHESIS-STUTTGART, 20, 3375, 3377, GEORG THIEME VERLAG KG, Oct. 2009, [Peer-reviewed]
English, Scientific journal, Synthesis of 2,3,3,3-tetrafluoro-2-(3-phenoxyphenyl)propanoic acid and 2-(3-benzoylphenyl)-2,3,3,3-tetrafluoropropanoic acid (tetrafluorinated fenoprofen and ketoprofen) was achieved by electrochemical carboxylation of pentafluoroethylarenes.

Synthesis of Isoindolobenzazepine Alkaloids Based on Radical Reactions or Pd(0)-Catalyzed Reactions
Yu Onozaki, Nobuhito Kurono, Hisanori Senboku, Masao Tokuda, Kazuhiko Orito
JOURNAL OF ORGANIC CHEMISTRY, 74, 15, 5486, 5495, AMER CHEMICAL SOC, Aug. 2009, [Peer-reviewed]
English, Scientific journal, Methods for synthesis of a ring system characteristic of isoindolobenzazepine alkaloids were studied. Synthesis of lennoxamine and a formal synthesis of chelenine were accomplished in a short route via radical or Pd(0)-catalyzed cyclization as the key step. An altenative approach based on a radical migration of a cyano group or Pd(0)-catalyzed carbonylation was also developed for both alkaloids.

Synthesis of Isoindolobenzazepine Alkaloids Based on Radical Reactions or Pd(0)-Catalyzed Reactions. (vol 74, pg 5486, 2009)
Yu Onozaki, Nobuhito Kurono, Hisanori Senboku, Masao Tokuda, Kazuhiko Orito
JOURNAL OF ORGANIC CHEMISTRY, 74, 16, 6414, 6414, AMER CHEMICAL SOC, Aug. 2009
English

Synthesis of Phenanthro[9,10-b]indolizidin-9-ones, Phenanthro[9,10-b]quinolizidin-9-one, and Related Benzolactams by Pd(OAc)(2)-Catalzed Direct Aromatic Carbonylation
Satoshi Yamashita, Nobuhito Kurono, Hisanori Senboku, Masao Tokuda, Kazuhiko Orito
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, 2009, 8, 1173, 1180, WILEY-BLACKWELL, Mar. 2009, [Peer-reviewed]
English, Scientific journal, Phenanthro[9,10-b]indolizidin-9-ones, phenanthro[9,10-b]-quinolizidin-9-one, and related benzolactam were synthesized by benzolactam ring formation using Pd(OAc)(2)-catalyzed direct aromatic carbonylation. This also constitutes a formal synthesis of the representative phenanthroindolizidine and -quinolizidine alkaloids (+/-)-tylophorine, (+/-)-antofine, and (+/-)-cryptopleurine. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

An in situ high pressure FTIR study on molecular interactions of ketones, esters, and amides with dense phase carbon dioxide
Y. Akiyama, S. Fujita, H. Senboku, C. M. Rayner, S. A. Brough, M. Arai
JOURNAL OF SUPERCRITICAL FLUIDS, 46, 2, 197, 205, ELSEVIER SCIENCE BV, Sep. 2008, [Peer-reviewed]
English, Scientific journal, The interactions between a variety of carbonyl compounds (ketones, esters, and amides) and dense phase CO2 have been investigated by in situ high pressure FTIR measurements. The gas and liquid phase spectra of these compounds have also been measured to provide accurate reference data, and these have been compared with those obtained in n-hexane and dense phase CO2 at a variety of pressures. The frequency of the carbonyl IR absorption is a measure of the strength of the carbonyl bond, and in the dense CO2 medium, is in between that observed in the gaseous and liquid phases. The substituent effect on the v(C=O) absorption bands is the same for the gas, liquid, and dense CO2 spectra and it is related to the electron donating nature of the substituents. When solutions of carbonyl compounds in n-hexane are diluted, the v(C=O) absorption bands are blue-shifted. In contrast, these bands in dense CO2 are red-shifted with increasing pressure (dilution by CO2). The red shift with increasing CO2 pressure is larger in amides > esters > ketones. (c) 2008 Elsevier B.V. All rights reserved.

Rhodium-catalyzed ring-opening reactions of N-Boc-azabenzonorbornadiene with chiral amine nucleophiles derived from amino acids
Yong-Hwan Cho, Nai-Wen Tseng, Hisanori Senboku, Mark Lautens
SYNTHESIS-STUTTGART, 15, 2467, 2475, GEORG THIEME VERLAG KG, Aug. 2008, [Peer-reviewed]
English, Scientific journal, The rhodium-catalyzed ring-opening of azabenzonorbomadienes with chiral amino nucleophiles derived from amino acids such as (5)-proline and (R)-phenylglycine is reported. The desired products were obtained as a mixture of diastereomers, which Could be easily separated in high yield. Enantiomerically pure ring-fused nitrogen heterocycles and 1.2-diamines were also obtained by further transformation of the ring-opened products.

Electrochemical carboxylation of alpha,alpha-difluorotoluene derivatives and its application to the synthesis of alpha-fluorinated nonsteroidal anti-inflammatory drugs
Yusuke Yamauchi, Tsuyoshi Fukuhara, Shoji Hara, Hisanori Senboku
SYNLETT, 3, 438, 442, GEORG THIEME VERLAG KG, Feb. 2008, [Peer-reviewed]
English, Scientific journal, Electrochemical carboxylation of alpha,alpha-difluorotoluene derivatives resulted in an efficient fixation of carbon dioxide to give the corresponding alpha-fluorophenylacetic acids in good yields, and this reaction was successfully applied to the synthesis of a-fluorinated nonsteroidal anti-inflammatory drugs (NSAIDs).

An efficient synthesis of fluorocyclopentenes using fluoroalkylidenecarbenes
Tong Guan, Kohei Takemura, Hisanori Senboku, Masanori Yoshida, Shoji Hara
TETRAHEDRON LETTERS, 49, 1, 76, 79, PERGAMON-ELSEVIER SCIENCE LTD, Jan. 2008, [Peer-reviewed]
English, Scientific journal, An efficient synthesis of fluorocyclopentenes is described. By treatment of (2-fluoroalkenyl)iodonium salts with potassium tert-butoxide, (alpha-fluoroalkylidene)carbenes were generated efficiently to give fluorocyclopentenes via 1,5-C-H insertion. Fluorocyclopentenes having a functionality, such as chlorine, acetoxy, or ketone, and a spiro fluorocyclopentene were synthesized in good yields. (C) 2007 Elsevier Ltd. All rights reserved.

Polycyclic aromatic compounds-mediated electrochemical reduction of alkyl mesylates
Hisanori Senboku, Megumi Takahashi, Tsuyoshi Fukuhara, Shoji Hara
CHEMISTRY LETTERS, 36, 2, 228, 229, CHEMICAL SOC JAPAN, Feb. 2007, [Peer-reviewed]
English, Scientific journal, Electrochemical reduction of alkyl mesylates was successfully carried out by using an undivided cell equipped with a Pt cathode and an Mg anode in the presence of biphenyl and t-BuOH. The reaction could proceed efficiently under mild conditions to give the corresponding alkanes in moderate to good yields. This procedure could also be applicable to chemoselective reduction of mesylates having functional groups such as epoxide, olefin, acetal, hydroxy, or cyano groups.

Preparation of cyclic urethanes from amino alcohols and carbon dioxide using ionic liquid catalysts with alkali metal promoters
Shin-ichiro Fujita, Hiroshi Kanamaru, Hisanori Senboku, Masahiko Arai
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES, 7, 10, 438, 450, MDPI AG, Oct. 2006, [Peer-reviewed]
English, Scientific journal, Several ionic liquids were applied as catalysts for the synthesis of cyclic urethanes from amino alcohols and pressurized CO2 in the presence of alkali metal compounds as promoters. A comparative study was made for the catalytic performance using different ionic liquids, substrates, promoters, and pressures. The optimum catalytic system was BMIM-Br promoted by K2CO3, which, for 1-amino-2-propanol, produced cyclic urethane in 40% yield with a smaller yield of substituted cyclic urea and no oligomeric byproducts. For other amino alcohols, cyclic urethanes, cyclic ureas, and/or undesired byproducts were produced in different yields depending on the substrates used. Possible reaction mechanisms are proposed.

Electrochemical carboxylation of aliphatic ketones: Synthesis of beta-keto carboxylic acids
Hisanori Senboku, Yusuke Yamauchi, Tsuyoshi Fukuhara, Shoji Hara
ELECTROCHEMISTRY, 74, 8, 612, 614, ELECTROCHEMICAL SOC JAPAN, Aug. 2006, [Peer-reviewed]
English, Scientific journal, A constant current electrolysis of saturated aliphatic ketones in a CH3CN or DMF solution containing 0.1 mol din (-3) Bu4NBF4 with a platinum cathode and a magnesium anode under an atmospheric pressure of CO2 resulted in an efficient fixation of CO2 at a-position of carbonyl group in the ketones to give the corresponding P-keto carboxylic acids in moderate to good yields.

Rhodium-catalyzed ring-opening reactions of N-boc-azabenzonorbornadienes with amine nucleophiles
Yong-hwan Cho, Valentin Zunic, Hisanori Senboku, Madeline Olsen, Mark Lautens
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 128, 21, 6837, 6846, AMER CHEMICAL SOC, May 2006, [Peer-reviewed]
English, Scientific journal, In the presence of a rhodium catalyst (5 mol %) generated in situ from [Rh(cod)Cl](2) and (S,S')- (R,R')-C-2-ferriphos(4a), the asymmetric ring-opening reaction of azabenzonorbornadienes (1a-m) with various aliphatic and aromatic amines (2a-I) proceeded with high enantioselectivity (up to > 99% ee) to give the corresponding 1,2-diamine derivatives 3 in high yields. In the specific case of pyrrolidine as nucleophile, Et3NHCI was necessary as an additive for good reactivity and enantioselectivity. Additionally, a practical protocol was developed for the ring-opening of 1a with volatile amines at elevated temperatures and standard pressure, using R2NH2I and i-Pr2NEt. The experimental results showed that the nature of the chiral ligand has the significant impact on the reactivity of the catalyst and the use of excess amount (2.2 eq to Rh) of the chiral ligand plays an important role to improve the enantioselectivity in the present asymmetric reaction.

Stereoselective synthesis of (E)-beta-arylvinyl bromides by microwave-induced Hunsdiecker-type reaction
CX Kuang, Q Yang, H Senboku, M Tokuda
SYNTHESIS-STUTTGART, 8, 1319, 1325, GEORG THIEME VERLAG KG, May 2005, [Peer-reviewed]
English, Scientific journal, (E)-beta-Arylvinyl bromides were readily prepared in a short reaction time (1-2 min) by microwave irradiation of the corresponding 3-arylpropenoic acids in the presence of N-bromosuccinimide and a catalytic amount of lithium acetate. Furthermore, two facile strategies for the efficient synthesis of (E)-beta-broMo-4-arylethynylstyrene and (E)-beta-bromo-4-arylstyrene have been developed by respectively combining Sonogashira and Suzuki coupling reaction with Hunsdiecker-type reaction. Formation of cis-alpha-bromo-beta-lactone by microwave irradiation of cis-cinnamic acid with NBS provides a useful support for the mechanistic study of the present halodecarboxylation reaction.

Rapid debromination of vic-dibromoalkanes with zinc powder in acetic acid under microwave irradiation
CX Kuang, Q Yang, H Senboku, M Tokuda
JOURNAL OF CHEMICAL RESEARCH-S, 5, 282, 284, SCIENCE REVIEWS LTD, May 2005, [Peer-reviewed]
English, Scientific journal, Microwave irradiation of vic-dibromoalkanes in acetic acid containing zinc powder for 1-2 min gave the corresponding alkenes in high yields.

Synthesis of (Z)-1-bromo-1-alkenes and terminal alkynes from anti-2,3-dibromoalkanoic acids by microwave-induced reaction
CX Kuang, Q Yang, H Senboku, M Tokuda
TETRAHEDRON, 61, 16, 4043, 4052, PERGAMON-ELSEVIER SCIENCE LTD, Apr. 2005, [Peer-reviewed]
English, Scientific journal, (Z)-1-Bromo-1-alkenes were stereoselectively prepared in high yields in a short reaction time by microwave irradiation of the corresponding anti-2,3-dibromoalkanoic acids in a Et3N/DMF system. A one-pot synthesis of terminal alkynes and enynes from 2,3-dibromoalkanoic acids were also developed by microwave-induced reaction. (c) 2005 Elsevier Ltd. All rights reserved.

Stereospecific electrochemical carboxylation of beta-bromostyrene by use of nickel(II) catalyst
CX Kuang, Q Yang, H Senboku, M Tokuda
CHEMISTRY LETTERS, 34, 4, 528, 529, CHEMICAL SOC JAPAN, Apr. 2005, [Peer-reviewed]
English, Scientific journal, Electrochemical carboxylation of (E)- and (Z)-beta-bromostyrenes (1) under an atmospheric pressure of carbon dioxide with a platinum cathode and a magnesium anode in the presence of 20 mol % of NiBr2 center dot bpy proceeded with retention of stereochemistry to give the corresponding (E)- or (Z)-cinnamic acids (2). The stereochemical outcome of nickel(II)-catalyzed electrochemical carboxylations was discussed by comparison with predominant formation of a (Z)-isomer from either (E)- or (Z)-beta-bromostyrenes.

Stereoselective synthesis of (E)-beta-arylvinyl bromides by microwave-induced reaction of anti-3-aryl-2,3-dibromopropanoic acids using an AgOAc-AcOH system
CX Kuang, H Senboku, M Tokuda
TETRAHEDRON, 61, 3, 637, 642, PERGAMON-ELSEVIER SCIENCE LTD, Jan. 2005, [Peer-reviewed]
English, Scientific journal, (E)-beta-Arylvinyl bromides were stereoselectively prepared in high yields by microwave irradiation of the corresponding anti-3-aryl-2,3-dibromopropanoic acids in AcOH in the presence of AgOAc for 0.5-3.0 min. (C) 2004 Elsevier Ltd. All rights reserved.

A one-pot synthesis of terminal alkynes from anti-3-aryl-2,3-dibromopropanoic acids under microwave irradiation
CX Kuang, H Senboku, M Tokuda
CHEMISTRY LETTERS, 34, 1, 28, 29, CHEMICAL SOC JAPAN, Jan. 2005, [Peer-reviewed]
English, Scientific journal, A facile one-pot synthesis of terminal alkynes was achieved by microwave irradiation of a mixture of anti-3-aryl-2,3-dibromopropanoic acids, Et3N and DMF and subsequent irradiation in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). This method requires short reaction time (1-2min) and gives terminal alkynes in high yields.

Stereoselective synthesis of 5-7 membered cyclic ethers by deiodonative ring-enlargement using hypervalent iodine reagents
T Abo, M Sawaguchi, H Senboku, S Hara
MOLECULES, 10, 1, 183, 189, MOLECULAR DIVERSITY PRESERVATION INTERNATIONAL, Jan. 2005, [Peer-reviewed]
English, Scientific journal, Stereoselective synthesis of 5-7 membered cyclic ethers was achieved by deiodonative ring-enlargement of cyclic ethers having an iodoalkyl substituent. The reaction took place readily under mild conditions using hypervalent iodine compounds and an acetoxy or a trifluoroacetoxy group was introduced into the rings depending on the hypervalent iodine reagent employed. The use of hexafluoroisopropanol (HFIP) as solvent is critical.

A convenient synthesis of highly substituted furans by microwave irradiation of ring-fused alkylidenecyclopropanes
MA Chowdhury, H Senboku, M Tokuda
SYNLETT, 11, 1933, 1936, GEORG THIEME VERLAG KG, Sep. 2004, [Peer-reviewed]
English, Scientific journal, Microwave irradiation of ring-fused alkylidenecyclopropanes under solvent-free conditions afforded highly substituted furans in good yields.

Electrochemical carboxylation of bicyclo[n.1.0]alkylidene derivatives
MA Chowdhury, H Senboku, M Tokuda
TETRAHEDRON, 60, 2, 475, 481, PERGAMON-ELSEVIER SCIENCE LTD, Jan. 2004, [Peer-reviewed]
English, Scientific journal, Electrochemical carboxylation of bicyclo[n.1.0]alkylidene derivatives (ring-fused alkylidenecyclopropanes) in a suitable aprotic solvent using a one-compartment electrochemical cell equipped with a platinum plate cathode and a zinc plate anode under an atmospheric pressure of carbon dioxide afforded either mono- or dicarboxylic acid in moderate to good yields. (C) 2003 Elsevier Ltd. All rights reserved.

A new synthesis of ring-fused alkylidenecyclobutanes by ring-enlargement reaction of bicyclo[n.1.0]alkylidene derivatives
MA Chowdhury, H Senboku, M Tokuda
TETRAHEDRON LETTERS, 44, 16, 3329, 3332, PERGAMON-ELSEVIER SCIENCE LTD, Apr. 2003, [Peer-reviewed]
English, Scientific journal, Bicyclo[n.1.0]alkylidene derivatives (ring-fused alkylidenecyclopropanes) reacted with diazomethane to give spiro-pyrazolines regioselectively. Thermal decomposition of spiro-pyrazolines resulted in ring-enlargement and afforded ring-fused alkylidenecyclobutanes (bicyclo[n.2.0]alkylidene derivatives) in high yields. (C) 2003 Elsevier Science Ltd. All rights reserved.

Stereoselective synthesis of 2-methylenepyrrolizidines by tandem cyclization of N-propargylaminyl radicals
H Hasegawa, H Senboku, Y Kajizuka, K Orito, M Tokuda
TETRAHEDRON, 59, 6, 827, 832, PERGAMON-ELSEVIER SCIENCE LTD, Feb. 2003, [Peer-reviewed]
English, Scientific journal, Tandem cyclization of N-propargylaminyl radicals, generated by N-chlorination of (E)-alk-4-enylamines 2a-d and 2f followed by treatment with tributyltin radical, afforded 2-methylenepyrrolizidines 3a-d and 3f in a highly stereoselective manner. A similar radical cyclization of (Z)-N-propargyl-1-methyl-5-phenylpent-4-enylamine (2e) gave pyrrolizidine 3b having the same stereochemistry as that obtained from the E isomer 2b. (C) 2003 Elsevier Science Ltd. All rights reserved.

Selective hydrogenation of phenylacetylene with graphite intercalated platinum nanosheets
M Shirai, BM Bhanage, H Senboku, S Fujita, M Arai
JOURNAL OF THE JAPAN PETROLEUM INSTITUTE, 45, 6, 420, 421, JAPAN PETROLEUM INST, Nov. 2002, [Peer-reviewed]
English, Scientific journal, Platinum nanosheets between graphite layers were active for hydrogenation of ethynyl group of phenylacetylene but less active for that of aromatic rings of phenylacetylene and benzene due to its structural characteristics.

Stereoselective preparation of 7-exo-amino-7-endo-substituted bicyclo[4.1.0]heptanes
MA Chowdhury, H Senboku, M Tokuda, T Chiba
TETRAHEDRON, 58, 9, 1673, 1677, PERGAMON-ELSEVIER SCIENCE LTD, Feb. 2002, [Peer-reviewed]
English, Scientific journal, Bicyclo[4.1.0]heptan-7-one N,O-hemiacetals undergo substitution reaction with Wittig reagents (Ph3P==CHR3) to give stereoselectively the corresponding 7-exo-amino-7-endo-substituted bicyclo[4.1.0]heptanes in good yields. (C) 2002 Elsevier Science Ltd. All rights reserved.

Facile and stereoselective synthesis of (E)-vinyl bromides by microwave-induced reaction of 1,1-dibromoalkenes using a diethyl phosphonate/EtONa/EtOH system
CX Kuang, H Senboku, M Tokuda
TETRAHEDRON, 58, 8, 1491, 1496, PERGAMON-ELSEVIER SCIENCE LTD, Feb. 2002, [Peer-reviewed]
English, Scientific journal, (E)-Vinyl bromides were readily prepared from 1,1-dibromoalkenes by microwave irradiation within 1 min using a diethyl phosphonate/EtONa/EtOH system. This method utilizes cheap and environmentally friendly reagents, requires only a short reaction time, and gives (E)-vinyl bromides in high stereoselectivities and high yields. (C) 2002 Elsevier Science Ltd. All rights reserved.

Convenient synthesis of cyclic alpha-alkoxyl-alpha,beta-unsaturated carboxylic acids by nickel-catalyzed electrochemical carboxylation of lactone enol triflates
H Senboku, H Kanaya, M Tokuda
SYNLETT, 1, 140, 142, GEORG THIEME VERLAG KG, Jan. 2002, [Peer-reviewed]
English, Scientific journal, Electrochemical carboxylation of lactone enol triflates in DMF containing a catalytic amount of NiBr2.bpy with a platinum cathode and a magnesium anode under an atmospheric pressure of CO2 gave the corresponding cyclic alpha-alkoxyl-alpha,beta-unsaturated carboxylic acids, captodative cycloalkenes, in good yields.

A facile synthesis of ring-fused alkylidenecyclopropanes by olefination reaction of bicyclo[n.1.0]alkanone N,O-hemiacetals with Wittig reagents
MA Chowdhury, H Senboku, M Tokuda, Y Masuda, T Chiba
TETRAHEDRON LETTERS, 42, 40, 7075, 7078, PERGAMON-ELSEVIER SCIENCE LTD, Oct. 2001, [Peer-reviewed]
English, Scientific journal, Ring-fused alkylidenecyclopropanes. bicyclo[n.1.0]alkylidene derivatives, were readily synthesized by olefination reaction of bicyclo[n.l.0]alkanone N,O-hemiacetals with Wittig reagents in good yields. (C) 2001 Elsevier Science Ltd. All rights reserved.

Stereochemical study on electrochemical carboxylation of vinyl triflates
H Senboku, H Kanaya, Y Fujimura, M Tokuda
JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 507, 1-2, 82, 88, ELSEVIER SCIENCE SA, Jul. 2001, [Peer-reviewed]
English, Scientific journal, A stereochemical study on electrochemical carboxylation of ethoxycarbonyl- or phenyl-substituted vinyl triflates was carried out. Vinyl triflates in DMF with a platinum cathode and a magnesium anode underwent electrochemical carboxylation with retention of their geometries to give the corresponding alpha,beta -unsaturated carboxylic acids in moderate to good yields. The stereochemical outcome of these electrochemical carboxylations is discussed by comparison with predominant formation of a (Z)-isomer from either (E)- or (Z)-vinyl bromides. (C) 2001 Elsevier Science B.V. All rights reserved.

Convenient and stereoselective synthesis of (Z)-1-bromo-1-alkenes by microwave-induced reaction
CX Kuang, H Senboku, M Tokuda
TETRAHEDRON LETTERS, 42, 23, 3893, 3896, PERGAMON-ELSEVIER SCIENCE LTD, Jun. 2001, [Peer-reviewed]
English, Scientific journal, (Z)-l-Bromo-l-alkenes were stereoselectively prepared in high yields in a short reaction time (0.2 1.0 min) by microwave irradiation of the corresponding 2,3-dibromoalkanoic acids in DMF in the presence of triethylamine. (C) 2001 Elsevier Science Ltd. All rights reserved.

Efficient electrochemical dicarboxylation of phenyl-substituted alkenes: Synthesis of 1-phenylalkane-1,2-dicarboxylic acids
H Senboku, H Komatsu, Y Fujimura, M Tokuda
SYNLETT, 3, 418, 420, GEORG THIEME VERLAG KG, Mar. 2001, [Peer-reviewed]
English, Scientific journal, Electrochemical dicarboxylation of phenyl-substituted alkenes in the presence of atmospheric pressure of carbon dioxide with a platinum plate cathode and a magnesium rod anode readily took place efficiently in a DMF solution containing 0.1 M Et4ClO4 to give the corresponding 1,2-dicarboxylic acids in high yields.

Stereoselective synthesis of (E)-beta-arylvinyl halides by microwave-induced Hunsdiecker reaction
CX Kuang, H Senboku, M Tokuda
SYNLETT, 10, 1439, 1442, GEORG THIEME VERLAG, Oct. 2000, [Peer-reviewed]
English, Scientific journal, (E)-beta-Arylvinyl halides were prepared in high yields in a short reaction (1-2 min) by microwave irradiation of the corresponding 3-arylpropenoic acids in the presence of N-halosuccinimide and catalytic LiOAc.

Exclusive 1,4-aryl migration in a stereoselective cyclization of N-benzylalk-4-enylaminyl radicals
H Senboku, H Hasegawa, K Orito, M Tokuda
TETRAHEDRON LETTERS, 41, 30, 5699, 5703, PERGAMON-ELSEVIER SCIENCE LTD, Jul. 2000, [Peer-reviewed]
English, Scientific journal, Tandem cyclization of N-benzylalk-4-enylaminyl radicals readily occurs to give 1,4-aryl migration pyrrolidines, trans-N-methyl-2-alkyl-5-(1-phenylalkyl)pyrrolidines, exclusively. (C) 2000 Elsevier Science Ltd. All rights reserved.

Divergent electrochemical carboxylation of vinyl triflates: new electrochemical synthesis of phenyl-substituted alpha,beta-unsaturated carboxylic acids and aliphatic beta-keto carboxylic acids
H Senboku, Y Fujimura, H Kamekawa, M Tokuda
ELECTROCHIMICA ACTA, 45, 18, 2995, 3003, PERGAMON-ELSEVIER SCIENCE LTD, 2000, [Peer-reviewed]
English, Scientific journal, Electrochemical carboxylation of vinyl triflates using a magnesium anode, as a reactive metal electrode, was investigated. Alkyl-substituted vinyl triflates were electrolyzed in the presence of an atmospheric pressure of carbon dioxide to give beta-keto carboxylic acids as a sole products. On the other hand, electrochemical carboxylation of phenyl-substituted vinyl triflates gave alpha,beta-unsaturated carboxylic acids exclusively. These divergent electrochemical carboxylation resulted from chemoselective cleavage of O-S or C-O bond of vinyl triflate, which was affected by the presence or absence of phenyl substituents in the structure of starting vinyl triflates. (C) 2000 Elsevier Science Ltd. All rights reserved.

Tandem cyclization of N-allylaminyl radicals: Stereoselective synthesis of 1,2,5-trisubstituted pyrrolizidines
H Senboku, Y Kajizuka, H Hasegawa, H Fujita, H Suginome, K Orito, M Tokuda
TETRAHEDRON, 55, 21, 6465, 6474, PERGAMON-ELSEVIER SCIENCE LTD, May 1999, [Peer-reviewed]
English, Scientific journal, Radical reaction of N-allylalk-4-enylaminyl radicals, generated from the corresponding N-chloroamines by treatment with Bu3SnH-AIBN in refluxing toluene, was carried out. Tandem cyclization of the resulting neutral aminyl radicals readily took place stereoselectively to give 1,2,5-trisubstituted pyrrolizidines and a pyrroloindole derivative as a sole product in good yields. The cyclization products contained only two stereoisomers in each reaction, indicating that both of the consecutive cyclizations proceeded in a stereoselective manner. (C) 1999 Elsevier Science Ltd. All rights reserved.

New stereoselective synthesis of (+/-)-trans-2-butyl-5-heptyl-1-methylpyrrolidine, ant venom alkaloid, by aminyl radical cyclization
H Senboku, H Hasegawa, K Orito, M Tokuda
HETEROCYCLES, 50, 1, 333, 340, PERGAMON-ELSEVIER SCIENCE LTD, Jan. 1999, [Peer-reviewed]
English, Scientific journal, New synthesis of (+/-)-trans-2-butyl-5-heptyl-1-methylpyrrolidine (1), ant venom alkaloid, was achieved by the use of stereoselective cyclization of aminyl radicals. Thus, orthoester Claisen rearrangement of 1-hexen-3-ol (2) gave (E)-ethyl 4-octenoate (3). Reaction of ester (3) with 2-methylaminopyridine and AlCl3 afford ed the corresponding N-methyl-N-(2-pyridyl)amide (4), which was treated with heptylmagnesium iodide at -78 degrees C to give (E)-4-pentadecen-8-one (5). Reductive amination of ketone (5) with methylamine gave N-methyl-1-heptyl-4-octenylamine (6). Treatment of amine (6) with NCS in toluene gave the corresponding N-chloroamine (12), and successive heating under reflux with Bu3SnH and AIBN resulted in stereoselective cyclization of the aminyl radical to give (+/-)-trans-2-butyl-5-heptyl-1-methylpyrrolidine (1) in a 59% yield. Similarly, 1-nonen-3-ol (7) was converted into N-methyl-1-butyl-4-undecenylamine (11), which was subjected to the aminyl radical cyclization to give 1 in a 49% yield.

New electrochemical carboxylation of vinyl triflates. Synthesis of beta-keto carboxylic acids
H Kamekawa, H Senboku, M Tokuda
TETRAHEDRON LETTERS, 39, 12, 1591, 1594, PERGAMON-ELSEVIER SCIENCE LTD, Mar. 1998, [Peer-reviewed]
English, Scientific journal, Electrochemical reduction of alicyclic vinyl triflates (1a-1e) in a DMF solution containing 0.1 M Bu4NBF4 under an atmospheric pressure of carbon dioxide with a platinum cathode and a magnesium anode resulted in the cleavage of an oxygen-sulfur bond of 1 to give the corresponding beta-keto carboxylic acids (2a-2e) in yields of 28-77%. (C) 1998 Elsevier Science Ltd. All rights reserved.

Synthesis of (+/-)-nitramine and (+/-)-isonitramine by utilizing stereoselective reduction of ethyl 1-(3-bromopropyl)-2-oxocyclohexanecarboxylate
H Senboku, M Hatazawa, K Orito, M Tokuda
HETEROCYCLES, 46, 413, 420, PERGAMON-ELSEVIER SCIENCE LTD, Dec. 1997, [Peer-reviewed]
English, Scientific journal, Formal synthesis of (+/-)-nitramine (1) and (+/-)-isonitramine (2) was achieved. Thus, the reduction of ethyl 1-(3-bromopropyl)-2-oxocyclohexanecarboxylate (6) with NaBH4 in MeOH gave the corresponding cyclohexanol (7) having cis geometry between hydroxyl and ester groups, predominantly. On the other hand, the trans located isomer (8) was preferentially obtained by reduction with LiAl(OBu')(3)H in THF. Treatment of the former reduction product (7) having cis geometry with benzylamine at 60 degrees C gave cis located ethyl 1-(3-(N-benzylamino)-propyl)-2-hydroxycyclohexanecarboxylate (9), which was further treated with BuLi to give a spirolactam, 2-benzyl-7-hydroxy-2-azaspiro[5,5]undecan-1-one (11) in 84% yield. Reduction of the lactam (11) with BH3 . SMe2 in THF gave N-benzylnitramine (13). In a similar manner, N-benzylisonitramine (14) was synthesized from trans located hydroxyaminoester (10).

New and convenient synthesis of 3-methylenepent-4-enoic acid by electrochemical carboxylation
M Tokuda, A Yoshikawa, H Suginome, H Senboku
SYNTHESIS-STUTTGART, 10, 1143, &, GEORG THIEME VERLAG, Oct. 1997, [Peer-reviewed]
English, Scientific journal, Electrochemical carboxylation of 2-bromomethyl-1,4-dibromobut-2-ene (1) with atmospheric carbon dioxide in a DMF solution containing Bu4NI with a platinum cathode and a manganin or nickel anode gave 3-methylenepent-4-enoic acid (3) in 57 % yield. The acid 3 can be used as a diene in an aqueous intermolecular Diels-Alder reaction with dimethyl fumarate to give the adduct 7 in 67 % yield.

Synthesis of alpha,beta-unsaturated carboxylic acids by nickel(II)-catalyzed electrochemical carboxylation of vinyl bromides
H Kamekawa, H Kudoh, H Senboku, M Tokuda
CHEMISTRY LETTERS, 9, 917, 918, CHEMICAL SOC JAPAN, 1997, [Peer-reviewed]
English, Scientific journal, Electrochemical carboxylation of alkyl-substituted vinyl bromides (1a-1g) in the presence of 20 mol% of NiBr2.bpy under an atmospheric pressure of carbon dioxide with a platinum cathode and a magnesium anode gave the corresponding alpha,beta-unsaturated carboxylic acids (2a-2g) in yields of 53-82%.

Photoinduced molecular transformations .160. Furan annelation of 2-hydroxynaphthoquinone involving photochemical addition and radical fragmentation: Exclusion of the intermediacy of [2+2] cycloadduct in a one-pot formation of furanoquinones by the regioselective 3+2 photoaddition of hydroxyquinones with alkenes
H Senboku, Y Kajizuka, K Kobayashi, M Tokuda, H Suginome
HETEROCYCLES, 44, 341, 348, PERGAMON-ELSEVIER SCIENCE LTD, Jan. 1997, [Peer-reviewed]
English, Scientific journal, 2-Acetoxy-1,4-naphthoquinone underwent [2+2] photoaddition to 2-methylpropene, giving a cyclobutanol acetate exclusively. Hydrolysis of the acetate with acid gave the corresponding cyclobutanol, which was stable under the conditions of an alkene-quinone photoaddition; hydrolysis with a base gave a fused 1-indanone derivative. Photolysis of the hypoiodite generated from the cyclobutanol derivative with mercury(II) oxide-iodine in benzene induced a beta-scission of the cyclobutanoxyl radical to give a 2,3-dihydronaphtho[2,3-b]furan-4,9-dione and its [1,2-b]furan-4,5-dione isomer.

Facile synthesis of aryl-substituted 2-alkenoic acids by electroreductive carboxylation of vinylic bromides using a magnesium anode
H Kamekawa, H Senboku, M Tokuda
ELECTROCHIMICA ACTA, 42, 13-14, 2117, 2123, PERGAMON-ELSEVIER SCIENCE LTD, 1997, [Peer-reviewed]
English, Scientific journal, Electrochemical carboxylation of phenyl-substituted vinylic bromides in the presence of atmospheric carbon dioxide using a platinum cathode and a magnesium anode gave the corresponding alpha,beta-unsaturated carboxylic acids in 63-92% isolated yields. A precursor of ibuprofen, 2-(pisobutylphenyl)propenoic acid, was readily obtained in a 93% yield by a similar electrochemical carboxylation of 1-bromo-1-(p-isobutylphenyl)ethene. Stereochemical studies showed that thermodynamically less stable Z-isomers were preferentially produced from either E- or Z-vinylic bromides in these electrochemical carboxylations. (C) 1997 Elsevier Science Ltd.

Photoinduced molecular transformations .159. Formation of some furonaphthyridinones by selective beta-scission of cyclobutanoxyl radicals generated from [2+2] photoadducts of 4-hydroxy-1-phenyl [1,8] naphthyridin-2(1H)-one with alkenes
H Senboku, M Takashima, M Suzuki, K Kobayashi, H Suginome
TETRAHEDRON, 52, 17, 6125, 6138, PERGAMON-ELSEVIER SCIENCE LTD, Apr. 1996, [Peer-reviewed]
English, Scientific journal, The [2+2] photoaddition of 4-hydroxy-1-phenyl[1,8]naphthyridin-2(1H)-one 7 with various alkenes in methanol gave regioselectively the corresponding head-to-tail adducts (8,9, and 11). The photolysis of the hypoiodites generated by the in situ reaction of the cyclobutanol adducts 8,9, and 11 with excess mercury(II) oxide-iodine reagent in benzene induced a regioselective scission of their non-ring junction bond of the corresponding alkoxyl radicals to give substituted 3,9-dihydro-9-phenylfuro[2,3-b][1,8]naphthyridin-4(2H)-one (12 and 15) and/or substituted 3,5-dihydro-5-phenylfuro[3,2-c][1,8]naphthyridin-4-(2H)-one (13,14, and 16). An unusual byproduct 12a was formed in the photolysis of the hypoiodite of the [2+2] photoadduct 8a of 4-hydroxy-1-phenyl[1,8]naphthyridin-2-(1H)-one with isobutene. (C) 1996 Elsevier Science Ltd.

PHOTOINDUCED MOLECULAR-TRANSFORMATIONS .156. NEW PHOTOADDITIONS OF 2-HYDROXY-1,4-NAPHTHOQUINONES WITH NAPHTHOLS AND THEIR DERIVATIVES
H SUGINOME, A KONISHI, H SAKURAI, H MINAKAWA, T TAKEDA, H SENBOKU, M TOKUDA, K KOBAYASHI
TETRAHEDRON, 51, 5, 1377, 1386, PERGAMON-ELSEVIER SCIENCE LTD, Jan. 1995, [Peer-reviewed]
English, Scientific journal, Dinaphtho[2,1-b;1',2'-d]furan-12,13-diones are produced in one-step in up to 45% yield by a (3+2) photoaddition of 2 hydroxy-1,4-naphthoquinones with 2-naphthol, while (+/-)-(6a alpha,6b beta,12a beta,12b alpha)-6a,6b,12a,12b-tetrahydro-12b-hydroxydinaphtho-[1,2-a;1',2'-c]cyclobutenes (14-16%), arising from the stereoselective addition of a (2+2) photoaddition, are products in the photoaddition of 2-hydroxy-1,4-naphthoquinone with 2-methoxynaphthalene and with 2-naphthyl acetate. The photoaddition of 2-hydroxy-1,4-naphthoquinone with 2-methoxynaphthalene also gave 2-hydroxy-3-(2-methoxynaphth-1-yl)-1,4-naphthoquinone (23%) as an accompanying product. Similar irradiation of a solution of 2-hydroxy-1,4-naphthoquinone with 1-methoxynaphthalene in acetone gave cis-6a,13a-dihydro-13a-methoxydinaphtho[1,2-b;2',3'-d]furan-7,12-dione arising from a (3+2) photoaddition in 24% yield. The probable mechanisms for the formation of the photoadducts are discussed.

PHOTOINDUCED MOLECULAR-TRANSFORMATIONS .154. ON THE MECHANISM OF THE FORMATION OF THE 5-IODOPENTYL FORMATE IN THE PHOTOLYSIS OF CYCLOPENTANOL HYPOIODITE IN SOLUTION IN THE PRESENCE OF MERCURY(II) OXIDE-IODINE
H SUGINOME, H SENBOKU
TETRAHEDRON, 50, 46, 13101, 13112, PERGAMON-ELSEVIER SCIENCE LTD, Nov. 1994, [Peer-reviewed]
English, Scientific journal, O-18-labelling experiments established that the formation of 5-iodopentyl formate in the photolysis of cyclopentanol hypoiodite in the presence of excess mercury(II) oxide-iodine in benzene involves the following pathway: a) a p-scission of a cyclopentyloxy radical to rearrange to a primary 5-oxopentyl radical, which generates the corresponding carbocation by a metal ion-assisted one-electron oxidation; b) an intramolecular addition of the 5-oxopentyl cation to the formyl oxygen to generate a tetrahydropyranyl cation; c) a combination of the tetrahydropyranyl cation with diiodine oxide (I2O) to form a lactol hypoiodite; d) generation of a carbon-centred radical by a selective beta-scission of a carbon-carbon bond of an alkoxyl radical generated from the lactol hypoiodite; e) abstraction of an iodine by the carbon-centred radical from an iodine molecule to form the 5-iodopentyl formate. 5-Iodopentyl formate is also produced by prolonged irradiation of a solution of 5-iodopentanal in the presence of mercury(II) oxide and iodine in benzene with Pyrex-filtered light. The formate in this case should be formed through the generation of the 5-oxopentyl cation (mentioned above) by mercury-assisted ionization of its carbon-iodine bond, followed by the same pathway as that mentioned above.

PHOTOINDUCED MOLECULAR-TRANSFORMATIONS .149. STEREOSPECIFIC PHOTOADDITIONS AND PHOTOREARRANGEMENTS OF THE OXIMES OF SOME STEROIDAL ALPHA,BETA-UNSATURATED CYCLIC-KETONES AND THEIR DEUTERIO DERIVATIVES
H SUGINOME, K OHSHIMA, Y OHUE, T OHKI, H SENBOKU
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1, 21, 3239, 3250, ROYAL SOC CHEMISTRY, Nov. 1994, [Peer-reviewed]
English, Scientific journal, The photolysis of several steroidal cyclic alpha,beta-unsaturated ketone oximes as model substrates in methanol showed that these excited oximes react in either one of two ways, depending upon their structural features. Thus, while the excited oximes. such as those of 5 alpha-Cholest-4-en-6-one and the 5-en-4-one oxime, having their C=C bond at their ring junction, lead to the corresponding enamides (15-40%) arising from a photorearrangement, the excited oximes, having their C=C bond at their non-ring junction (such as the oximes of 5 alpha-cholest-2-en-1-one and the 3-en-2-one). principally lead to photoisomerization to form transient trans geometrical isomers from which stereospecific additions of proton or methanol to their trans C=C bond take place.
The irradiation of (E)-5 alpha-cholest-2-en-1-one oxime in benzene-acetic acid (94:6) gave 1-aza-4a-homo-5a-cholest-3-en-2-one arising from a regioselective photorearrangement, while irradiation of the oxime in methanol gave 3 beta-methoxy-S alpha-cholestan-1-one arising from photoaddition in low yield. Thus, organic acid accelerates the photorearrangement to the lactam in competition to the alpha-fission.
In contrast to these photochemical transformations, ground-state Beckmann rearrangements of (E)-cholest-4-en-6-one oxime and (E)-cholest-5-en-4-one oxime. having their C=C bond at their ring junction, under the standard conditions gave the corresponding cyclic enamines. Treatment of (E)-5 alpha-cholest-2-en-1-one oxime under the standard conditions of the Beckmann rearrangement. however, gave an unsaturated nitrile as well as the corresponding enamide. The regioselectivities of the formation of cyclic enamine and enamides in the photo- and nonphoto-rearrangements, as well as the structure-photoproduct correlation of the oximes, are discussed.

PHOTOINDUCED MOLECULAR-TRANSFORMATIONS .145. REGIOSELECTIVE [3+2]-PHOTOADDITIONS OF 2-HYDROXYPHENANTHRENE-1,4-DIONE WITH ELECTRON-RICH ALKENES AND PHENYLACETYLENE - NEW ONE-STEP SYNTHESIS OF 9,10-DIHYDROPHENANTHRO-[2,3-B]FURAN-7,11-DIONES AND 2-PHENYLPHENANTHRO[2,3-B]FURAN-7,11-DIONE
H SUGINOME, H KAMEKAWA, H SAKURAI, A KONISHI, H SENBOKU, K KOBAYASHI
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1, 4, 471, 475, ROYAL SOC CHEMISTRY, Feb. 1994, [Peer-reviewed]
English, Scientific journal, The irradiation of 2-hydroxyphenanthrene-1,4-dione and various electron-rich alkenes such as ethyl vinyl ether, isobutene, 1-methoxycyclohexene and 3,4-dihydro-2H-pyran in acetone with Pyrex-filtered light gave 9,10-dihydrophenanthro[2,3-b]furan-7,11-diones arising from regioselective [3 + 2] photoaddition in 25-50% yields. A [3 t 2] photoadduct, 9-phenylphenanthro [2,3-b]furan-7,11-dione, can be similarly formed in low yield when 2-hydroxyphenanthrene-1,4-dione and phenylacetylene in acetone are irradiated with Pyrex-filtered light. In contrast, the irradiation of 2-hydroxyphenanthrene-1,4-dione and alkenes such as methyl acrylate, acrytonitrile, cyclohexene. isopropenyl acetate. propenyl acetate, vinyl acetate, 1-phenylprop-1-yne or trimethylsilylacetylene in acetone gave only a dimer in 42-52% yields, no [3 + 2] photoadducts being formed.

PHOTOINDUCED MOLECULAR-TRANSFORMATIONS .147. [2+2] PHOTOADDITION OF PROTECTED 4-HYDROXY-1(2H)-ISOQUINOLINONE WITH AN ELECTRON-DEFICIENT ALKENE AND THE FORMATION OF A 3,6-EPOXY-3,4,5,6-TETRAHYDRO-2-BENZAZOCIN-1(2H)-ONE VIA A BETA-SCISSION OF CYCLOBUTANOXYL RADICALS GENERATED FROM THE RESULTING PHOTOADDUCT
H SUGINOME, Y KAJIZUKA, M SUZUKI, H SENBOKU, K KOBAYASHI
HETEROCYCLES, 37, 1, 283, 288, PERGAMON-ELSEVIER SCIENCE LTD, Jan. 1994, [Peer-reviewed]
English, Scientific journal, The direct irradiation of 4-benzyloxycarbonyloxy-2-methyl-1(2H)-isoquinolinone gave a 1 to 1 ratio of two stereoisomers of [2+2] photoadducts in 97% yield. Removal of the protecting group from the adducts by hydrogenolysis gave the corresponding cyclobutanols, (1 alpha, 2a alpha, 8b alpha)-(+/-)-1-cyano-1,2a,3,8b-tetrahydro-8 b-hydroxy-3 -methylcyclobut[c]-isoquinolin-4(2H)-one and its (1 alpha, 2a beta, 8b beta)- isomer in 78 and 67% yields. The photolysis of the hypoiodite generated in situ from the (1 alpha, 2a alpha, 8b alpha)-(+/-)-cyclobutanol with mercury(II) oxide - iodine in benzene induced a regioselective beta-scission at the ring fusion bond of the cyclobutanoxyl radical to give 5-cyano-3,6-epoxy-3,4,5,6-tetrahydro-6-hydroxy-2-methyl-2- benzazocin-1(2H)-one in 76% yield. The cyano substituent and the amide nitrogen play a decisive role in directing the bond to be cleaved.

Photoinduced molecular transformations. Part 145. Regioselective [3 + 2] photoadditions of 2-hydroxyphenanthrene-1,4-dione with electron-rich alkenes and phenylacetylene: New one-step synthesis of 9,10-dihydrophenanthro[2,3-b]furan-7,11-diones and 2-phenylphenanthro[2,3-b]furan-7,11-dione
Hiroshi Suginome, Hisato Kamekawa, Hideo Sakurai, Atsushi Konishi, Hisanori Senboku, Kazuhiro Kobayashi
Journal of the Chemical Society, Perkin Transactions 1, 471, 475, 1994, [Peer-reviewed]
English, Scientific journal, The irradiation of 2-hydroxyphenanthrene-1, 4-dione and various electron-rich alkenes such as ethyl vinyl ether, isobutene, 1-methoxycyclohexene and 3,4-dihydro-2H-pyran in acetone with Pyrexfiltered light gave 9,10-dihydrophenanthro[2,3-b]furan-7,11-diones arising from regioselective [3 + 2] photoaddition in 25-50% yields. A [3 + 2] photoadduct, 9-phenylphenanthro[2,3-b]furan-7,11-dione, can be similarly formed in low yield when 2-hydroxyphenanthrene-1,4-dione and phenylacetylene in acetone are irradiated with Pyrex-filtered light. In contrast, the irradiation of 2-hydroxyphenanthrene-1,4-dione and alkenes such as methyl acrylate, acrylonitrile, cyclohexene, isopropenyl acetate, propenyl acetate, vinyl acetate, 1-phenylprop-1-yne or trimethylsilylacetylene in acetone gave only a dimer in 42-52% yields, no [3 + 2] photoadducts being formed. © 1994 by the Royal Society of Chemistry. All Rights Reserved.

PHOTOINDUCED MOLECULAR-TRANSFORMATIONS .134. PHOTOINDUCED STEREOSPECIFIC ADDITION OF METHANOL TO 5-BETA-CHOLEST-1-EN-3-ONE OXIME AND PHOTOINDUCED DECONJUGATION OF ITS 1-METHYL DERIVATIVE INVOLVING STEREOSPECIFIC PROTON-TRANSFER
H SUGINOME, A NAGAOKA, H SENBOKU
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1, 22, 3103, 3110, ROYAL SOC CHEMISTRY, Nov. 1992, [Peer-reviewed]
English, Scientific journal, Irradiation of 5beta-cholest-1-en-3-one oxime 14 in methanol gave 1alpha-methoxy-5beta-cholestan-3-one oxime 16, arising from the photoaddition of methanol to the double bond of the enone oxime. 1alpha-Methoxy-5beta-cholestan-3-one 17 as well as 10beta-methoxy-5(10 --> 1)abeo-1beta(H), 5beta, 10alpha(Me)cholestan-3-one 15, arising from a skeletal rearrangement of 5beta-cholest-1-en-3-one (generated from the oxime), were the accompanying products in this photoreaction. Deuterium-labelling studies confirmed that the formation of 1alpha-methoxy-5beta-cholestan-3-oxime 16 involves a stereospecific syn addition of methanol to the photogenerated, twisted, ground-state double bond of the oximes B from the rear side of the steroidal framework.
Irradiation of 1-methyl-5beta-cholest-1-en-3-one oxime 23 in methanol, on the other hand, gave almost exclusively 1-methylene-5beta-cholestan-3-one oxime 24, arising from photodeconjugation of the alpha,beta-double bond to the beta,gamma-position. A deuterium-labelling study established that deuterium is stereospecifically introduced at the 2beta-position of 1-methyl-5beta-cholest-1-en-3-one oxime 23 in the photodeconjugation in methanol [H-2]ol while deuterium is stereospecifically introduced at the 2alpha-position in the photodeconjugation of its 5alpha-isomer 6. These results are fully consistent with our previously proposed pathway concerning the photodeconjugation of 1-methyl-5alpha-cholest-1-en-3-one oxime 6; the stereospecific addition of a proton to the photogenerated, twisted double bond of the oxime D from the rear side of the steroidal framework was followed by the loss of a proton from the 1-methyl group of the resulting carbocation intermediate. Neither the isoxazole derivative, a product in the photoreaction of 5alpha-cholest-1-en-3-one oxime 1, nor the unsaturated lactam from a photo-Beckmann rearrangement was formed in the photoreactions of either 5beta-cholest-1-en-3-one oxime 14 or its 1-methyl derivative 23.

EFFICIENT FORMATION OF A SPIROTETRAHYDROFURAN RING BY THE IONIC CYCLIZATION OF BISHOMOALLYL TERTIARY ALCOHOLS VIA THEIR HYPOIODITES
H SUGINOME, H SENBOKU, A TSUNETOSHI
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1, 21, 2917, 2923, ROYAL SOC CHEMISTRY, Nov. 1992, [Peer-reviewed]
English, Scientific journal, Spirotetrahydrofuran derivatives are produced in high yields by an intramolecular cyclization of several steroidal bishomoallyl tertiary alcohols in benzene containing mercury(II) oxide and iodine at room temperature in the dark. 2-Hydroxy-2-(but-3-enyl)tetrahydrofuran thus cyclizes to give a mixture of the corresponding diastereoisomeric spirotetrahydrofurans in the dark.
An ionic mechanism for the formation of the tetrahydrofuran ring, which involves the formation of the hypoiodite followed by the cyclization of its iodonium ion, is proposed based on studies concerning several model substrates.

PHOTOINDUCED MOLECULAR-TRANSFORMATIONS .133. NEW PHOTOINDUCED DECONJUGATION OF STEROIDAL ALPHA,BETA-UNSATURATED CYCLIC KETONE OXIME INTO THE BETA,GAMMA-UNSATURATED ISOMER INVOLVING STEREOSPECIFIC PROTON-TRANSFER
H SUGINOME, T OHKI, A NAGAOKA, H SENBOKU
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1, 14, 1849, 1854, ROYAL SOC CHEMISTRY, Jul. 1992, [Peer-reviewed]
English, Scientific journal, Irradiation of 1-methyl-5-alpha-cholest-1-en-3-one oxime or its 4,4-dimethyl derivative in either a protic or an aprotic solvent gave 1-methylene-5-alpha-cholestan-3-one oxime or the corresponding 4,4-dimethyl derivative, arising from an unprecedented photodeconjugation of alpha,beta-enone oximes into the beta,gamma-isomers. Neither the expected isoxazole derivative (a product in the photoreaction of 5-alpha-cholest-1-en-3-one oxime or its 4,4-dimethyl derivative) nor the unsaturated lactam that arises from a photo-Beckmann rearrangement was formed. Deuterium-labelling studies on the photoreactions of 1-methyl-5-alpha-cholest-1-en-3-one oxime established that either a proton or a deuteron is stereospecifically introduced at the 2-alpha-position of the steroidal oxime in this photodeconjugation. A pathway which involves the sterospecific addition of either a proton or deuteron to the photogenerated, twisted double bond of the oximes from the rear side of the steroidal framework, followed by the loss of a proton or deuteron from the 1-methyl group of the resulting carbocation intermediate, is proposed regarding the formation of beta,gamma-unsaturated oximes from the excited alpha,beta-unsaturated oximes.

Photoinduced molecular transformations. Part 134. Photoinduced stereospecific addition of methanol to 5β-cholest-1-en-3-one oxime and photoinduced deconjugation of its 1-methyl derivative involving stereospecific proton transfer
Hiroshi Suginome, Atsushi Nagaoka, Hisanori Senboku
Journal of the Chemical Society, Perkin Transactions 1, 22, 3103, 3110, 1992
English, Scientific journal, Irradiation of 5β-cholest-1-en-3-one oxime 14 in methanol gave 1α-methoxy-5β-cholestan-3-one oxime 16, arising from the photoaddition of methanol to the double bond of the enone oxime. 1α-methoxy-5β-cholestan-3-one 17 as well as 10β-methoxy- 5(10→1)abeo-1β(H),5β,10α(Me)-cholestan-3-one 15, arising from a skeletal rearrangement of 5β-cholest-1-en-3-one (generated from the oxime), were the accompanying products in this photoreaction. Deuterium-labelling studies confirmed that the formation of 1α-methoxy- 5β-cholestan-3-oxime 16 involves a stereospecific syn addition of methanol to the photogenerated, twisted, ground-state double bond of the oximes B from the rear side of the steroidal framework. Irradiation of 1-methyl-5β- cholest-1-en-3-one oxime 23 in methanol, on the other hand, gave almost exclusively 1-methylene-5β-cholestan-3-one oxime 24, arising from photodeconjugation of the α,β-double bond to the β,γ- position. A deuterium-labelling study established that deuterium is stereospecifically introduced at the 2β-position of 1-methyl-5β- cholest-1-en-3-one oxime 23 in the photodeconjugation in methanol[ 2H]ol while deuterium is stereospecifically introduced at the 2α-position in the photodeconjugation of its 5α-isomer 6. These results are fully consistent with our previously proposed pathway concerning the photodeconjugation of 1-methyl-5α-cholest-1-en-3-one oxime 6
the stereospecific addition of a proton to the photogenerated, twisted double bond of the oxime D from the rear side of the steroidal framework was followed by the loss of a proton from the 1-methyl group of the resulting carbocation intermediate. Neither the isoxazole derivative, a product in the photoreaction of 5α-cholest-1-en-3-one oxime 1, nor the unsaturated lactam from a photo-Beckmann rearrangement was formed in the photoreactions of either 5β-cholest-1-en-3-one oxime 14 or its 1-methyl derivative 23.

Efficient formation of a spirotetrahydrofuran ring by the ionic cyclization of bishomoallyl tertiary alcohols via their hypoiodites
Hiroshi Suginome, Hisanori Senboku, Atsuhiko Tsunetoshi
Journal of the Chemical Society, Perkin Transactions 1, 21, 2917, 2923, 1992
English, Scientific journal, Spirotetrahydrofuran derivatives are produced in high yields by an intramolecular cyclization of several steroidal bishomoallyl tertiary alcohols in benzene containing mercury(II) oxide and iodine at room temperature in the dark. 2-Hydroxy-2-(but-3-enyl)tetrahydrofuran thus cyclizes to give a mixture of the corresponding diastereoisomeric spirotetrahydrofurans in the dark. An ionic mechanism for the formation of the tetrahydrofuran ring, which involves the formation of the hypoiodite followed by the cyclization of its iodonium ion, is proposed based on studies concerning several model substrates.

Photoinduced molecular transformations. Part 131. Synthesis of 18-norsteroids, deoxofukujusonorone and the related steroids, based on a selective β-scission of alkoxyl radicals as the key step
Hiroshi Suginome, Yutaka Nakayama, Hisanori Senboku
Journal of the Chemical Society, Perkin Transactions 1, 14, 1837, 1842, 1992, [Peer-reviewed]
English, Scientific journal, A new transformation of steroids into 18-norsteroids under mild conditions is described. The key step was a regioselective β-scission of the alkoxyl radicals generated by photolysis of the hypoiodite of 18-hydroxy-18,20α-epoxy steroids, prepared by photolysis of steroidal 20α-ol nitrites followed by deoximation of the resulting 18-hydroxyimino-20α-hydroxy steroid with sodium nitrite and acetic acid. 3β-Hydroxypregn-5-en-20-one (pregnenolone) was thus transformed into 3β-hydroxy-18-norpregna-5,13-dien-20-one (12-deoxofukujusonorone) in 10 steps. © Royal Society of Chemistry.

Photoinduced molecular transformations. Part 130. Novel stereospecific photorearrangement and stereospecific addition of methanol in steroidal α,β-unsaturated cyclic ketone oximes
Hiroshi Suginome, Makoto Kaji, Toshiharu Ohtsuka, Shinji Yamada, Takashi Ohki, Hisanori Senboku, Akio Furusaki
Journal of the Chemical Society, Perkin Transactions 1, 4, 427, 432, 1992, [Peer-reviewed]
English, Scientific journal, Irradiation of 5α-cholest-1-en-3-one oxime or its 4,4-dimethyl derivative in a protic or an aprotic solvent gave 4'α,5'-dihydro-4-nor-5α-cholest-1-eno[2,1-c]isoxazole or the corresponding 3,3-dimethyl derivative arising from an unprecedented photorearrangement. The molecular structure of the former was established by X-ray crystallographic analysis. 1β-Methoxy-5α-cholestan-3-one oximes or their 4,4-dimethyl derivatives, arising from an unprecedented photoaddition of methanol to the double bond of the enone oximes, were the accompanying products in both of these photoreactions and no lactams were formed. Deuterium-labelling studies on the photoreactions of 5α-cholest-1-en-3-one oxime and its trideuteriated derivative established that a deuteron or a proton is stereospecifically introduced at the 2α-position of the Steroidal oxime in this photorearrangement. A pathway which involves an unprecedented stereospecific addition of a proton or a deuteron to the photogenerated, twisted double bond of the oximes from the rear side, followed by fragmentation of the resulting carbocation and an intramolecular 1,3-dipolar addition of the nitrite oxide intermediate, is proposed regarding the formation of the isoxazole from the excited oximes. Deuterium-labelling studies also established that the addition of methanol to the double bond of the oximes is stereospecific too. On the basis of the labelling study it is concluded that the mechanism for the photoaddition of the methanol involves a stereospecific syn addition of the methanol to the photogenerated, twisted, ground-state double bond of the oximes from the rear side. © Royal Society of Chemistry.

PHOTOINDUCED MOLECULAR-TRANSFORMATIONS .112. TRANSFORMATION OF STEROIDS INTO RING-A-AROMATIZED STEROIDS AND 19-NORSTEROIDS INVOLVING A REGIOSELECTIVE BETA-SCISSION OF ALKOXYL RADICALS - SYNTHESIS OF 2 MARINE NATURAL-PRODUCTS, 19-NOR-5-ALPHA-CHOLESTAN-3-BETA-OL AND 19-NORCHOLEST-4-EN-3-ONE, AND NEW SYNTHESIS OF ESTRONE AND 19-NORTESTOSTERONE
H SUGINOME, H SENBOKU, S YAMADA
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1, 8, 2199, 2205, ROYAL SOC CHEMISTRY, Aug. 1990, [Peer-reviewed]
English, Scientific journal

Photoinduced molecular transformations. Part 112. Transformation of steroids into ring-A-aromatized steroids and 19-norsteroids involving a regioselective β-scission of alkoxyl radicals; synthesis of two marine natural products, 19-nor-5α-cholestan-3β-ol and 19-norcholest-4-en-3- one, and new synthesis of estrone and 19-nortestosterone
Hiroshi Suginome, Hisanori Senboku, Shinji Yamada
Journal of the Chemical Society, Perkin Transactions 1, 8, 2199, 2205, 1990
Scientific journal, A new transformation of steroids into 19-norsteroids and ring-A-aromatized steroids is described. The transformation method involves the removal of the 10β-methyl group by a regioselective β-scission of alkoxyl radicals. Cholesterol was transformed into two marine natural products, 19-nor-5α-cholestan-3β-ol and 19-norcholest-4-en-3-one, and into 19-norcholesta-1,3,5(10)-trien-3-ol. Transformations of 3β-hydroxyandrost- 5-en-17-one into 19-nortestosterone, estrone, and the related estranes are also described.

PHOTOINDUCED MOLECULAR TRANSFORMATIONS .93. A NEW AROMATIZATION OF RING-A OF STEROIDS - SYNTHESIS OF ESTRONE
H SUGINOME, H SENBOKU, S YAMADA
TETRAHEDRON LETTERS, 29, 1, 79, 80, PERGAMON-ELSEVIER SCIENCE LTD, 1988, [Peer-reviewed]
English, Scientific journal

A convenient synthesis of highly substituted furans by microwave irradiation of ring-fused alkylidenecyclopropanes
MA Chowdhury, H Senboku, M Tokuda, SYNLETT, 1933-1936, 11, 1933, 1936, Sep. 2004
Microwave irradiation of ring-fused alkylidenecyclopropanes under solvent-free conditions afforded highly substituted furans in good yields., GEORG THIEME VERLAG KG, English

Electrochemical carboxylation of bicyclo[n.1.0]alkylidene derivatives
MA Chowdhury, H Senboku, M Tokuda, TETRAHEDRON, 60, 2, 475, 481, Jan. 2004
Electrochemical carboxylation of bicyclo[n.1.0]alkylidene derivatives (ring-fused alkylidenecyclopropanes) in a suitable aprotic solvent using a one-compartment electrochemical cell equipped with a platinum plate cathode and a zinc plate anode under an atmospheric pressure of carbon dioxide afforded either mono- or dicarboxylic acid in moderate to good yields. (C) 2003 Elsevier Ltd. All rights reserved., PERGAMON-ELSEVIER SCIENCE LTD, English

A new synthesis of ring-fused alkylidenecyclobutanes by ring-enlargement reaction of bicyclo[n.1.0]alkylidene derivatives
MA Chowdhury, H Senboku, M Tokuda, TETRAHEDRON LETTERS, 44, 16, 3329, 3332, Apr. 2003
Bicyclo[n.1.0]alkylidene derivatives (ring-fused alkylidenecyclopropanes) reacted with diazomethane to give spiro-pyrazolines regioselectively. Thermal decomposition of spiro-pyrazolines resulted in ring-enlargement and afforded ring-fused alkylidenecyclobutanes (bicyclo[n.2.0]alkylidene derivatives) in high yields. (C) 2003 Elsevier Science Ltd. All rights reserved., PERGAMON-ELSEVIER SCIENCE LTD, English

Stereoselective synthesis of 2-methylenepyrrolizidines by tandem cyclization of N-propargylaminyl radicals
H Hasegawa, H Senboku, Y Kajizuka, K Orito, M Tokuda, TETRAHEDRON, 59, 6, 827, 832, Feb. 2003
Tandem cyclization of N-propargylaminyl radicals, generated by N-chlorination of (E)-alk-4-enylamines 2a-d and 2f followed by treatment with tributyltin radical, afforded 2-methylenepyrrolizidines 3a-d and 3f in a highly stereoselective manner. A similar radical cyclization of (Z)-N-propargyl-1-methyl-5-phenylpent-4-enylamine (2e) gave pyrrolizidine 3b having the same stereochemistry as that obtained from the E isomer 2b. (C) 2003 Elsevier Science Ltd. All rights reserved., PERGAMON-ELSEVIER SCIENCE LTD, English

超臨界二酸化炭素中における電気化学的手法による有機合成 (特集 超臨界二酸化炭素中における有機合成反応)
仙北 久典, 徳田 昌生, ファインケミカル, 31, 16, 50, 60, 15 Sep. 2002
シ-エムシ-, Japanese

Facile and stereoselective synthesis of (E)-vinyl bromides by microwave-induced reaction of 1,1-dibromoalkenes using a diethyl phosphonate/EtONa/EtOH system
CX Kuang, H Senboku, M Tokuda, TETRAHEDRON, 58, 8, 1491, 1496, Feb. 2002
(E)-Vinyl bromides were readily prepared from 1,1-dibromoalkenes by microwave irradiation within 1 min using a diethyl phosphonate/EtONa/EtOH system. This method utilizes cheap and environmentally friendly reagents, requires only a short reaction time, and gives (E)-vinyl bromides in high stereoselectivities and high yields. (C) 2002 Elsevier Science Ltd. All rights reserved., PERGAMON-ELSEVIER SCIENCE LTD, English

Stereoselective preparation of 7-exo-amino-7-endo-substituted bicyclo[4.1.0]heptanes
MA Chowdhury, H Senboku, M Tokuda, T Chiba, TETRAHEDRON, 58, 9, 1673, 1677, Feb. 2002
Bicyclo[4.1.0]heptan-7-one N,O-hemiacetals undergo substitution reaction with Wittig reagents (Ph3P==CHR3) to give stereoselectively the corresponding 7-exo-amino-7-endo-substituted bicyclo[4.1.0]heptanes in good yields. (C) 2002 Elsevier Science Ltd. All rights reserved., PERGAMON-ELSEVIER SCIENCE LTD, English

Convenient synthesis of cyclic alpha-alkoxyl-alpha,beta-unsaturated carboxylic acids by nickel-catalyzed electrochemical carboxylation of lactone enol triflates
H Senboku, H Kanaya, M Tokuda, SYNLETT, (1), 140-142, 1, 140, 142, Jan. 2002
Electrochemical carboxylation of lactone enol triflates in DMF containing a catalytic amount of NiBr2.bpy with a platinum cathode and a magnesium anode under an atmospheric pressure of CO2 gave the corresponding cyclic alpha-alkoxyl-alpha,beta-unsaturated carboxylic acids, captodative cycloalkenes, in good yields., GEORG THIEME VERLAG KG, English

A facile synthesis of ring-fused alkylidenecyclopropanes by olefination reaction of bicyclo[n.1.0]alkanone N,O-hemiacetals with Wittig reagents
MA Chowdhury, H Senboku, M Tokuda, Y Masuda, T Chiba, TETRAHEDRON LETTERS, 42, 40, 7075, 7078, Oct. 2001
Ring-fused alkylidenecyclopropanes. bicyclo[n.1.0]alkylidene derivatives, were readily synthesized by olefination reaction of bicyclo[n.l.0]alkanone N,O-hemiacetals with Wittig reagents in good yields. (C) 2001 Elsevier Science Ltd. All rights reserved., PERGAMON-ELSEVIER SCIENCE LTD, English

Stereochemical study on electrochemical carboxylation of vinyl triflates
H Senboku, H Kanaya, Y Fujimura, M Tokuda, JOURNAL OF ELECTROANALYTICAL CHEMISTRY, 507, 1-2, 82, 88, Jul. 2001
A stereochemical study on electrochemical carboxylation of ethoxycarbonyl- or phenyl-substituted vinyl triflates was carried out. Vinyl triflates in DMF with a platinum cathode and a magnesium anode underwent electrochemical carboxylation with retention of their geometries to give the corresponding alpha,beta -unsaturated carboxylic acids in moderate to good yields. The stereochemical outcome of these electrochemical carboxylations is discussed by comparison with predominant formation of a (Z)-isomer from either (E)- or (Z)-vinyl bromides. (C) 2001 Elsevier Science B.V. All rights reserved., ELSEVIER SCIENCE SA, English

Convenient and stereoselective synthesis of (Z)-1-bromo-1-alkenes by microwave-induced reaction
CX Kuang, H Senboku, M Tokuda, TETRAHEDRON LETTERS, 42, 23, 3893, 3896, Jun. 2001
(Z)-l-Bromo-l-alkenes were stereoselectively prepared in high yields in a short reaction time (0.2 1.0 min) by microwave irradiation of the corresponding 2,3-dibromoalkanoic acids in DMF in the presence of triethylamine. (C) 2001 Elsevier Science Ltd. All rights reserved., PERGAMON-ELSEVIER SCIENCE LTD, English

Efficient electrochemical dicarboxylation of phenyl-substituted alkenes: Synthesis of 1-phenylalkane-1,2-dicarboxylic acids
H Senboku, H Komatsu, Y Fujimura, M Tokuda, SYNLETT, (3), 418-420, 3, 418, 420, Mar. 2001
Electrochemical dicarboxylation of phenyl-substituted alkenes in the presence of atmospheric pressure of carbon dioxide with a platinum plate cathode and a magnesium rod anode readily took place efficiently in a DMF solution containing 0.1 M Et4ClO4 to give the corresponding 1,2-dicarboxylic acids in high yields., GEORG THIEME VERLAG KG, English

Stereoselective synthesis of (E)-beta-arylvinyl halides by microwave-induced Hunsdiecker reaction
CX Kuang, H Senboku, M Tokuda, SYNLETT, (10), 1439-1442, 10, 1439, 1442, Oct. 2000
(E)-beta-Arylvinyl halides were prepared in high yields in a short reaction (1-2 min) by microwave irradiation of the corresponding 3-arylpropenoic acids in the presence of N-halosuccinimide and catalytic LiOAc., GEORG THIEME VERLAG, English

超臨界二酸化炭素中での電気化学的手法による有機合成
仙北 久典, 徳田 昌生, Jasco report, 42, 1, 6, Aug. 2000
ジャスコレポ-ト社, Japanese

Exclusive 1,4-aryl migration in a stereoselective cyclization of N-benzylalk-4-enylaminyl radicals
H Senboku, H Hasegawa, K Orito, M Tokuda, TETRAHEDRON LETTERS, 41, 30, 5699, 5703, Jul. 2000
Tandem cyclization of N-benzylalk-4-enylaminyl radicals readily occurs to give 1,4-aryl migration pyrrolidines, trans-N-methyl-2-alkyl-5-(1-phenylalkyl)pyrrolidines, exclusively. (C) 2000 Elsevier Science Ltd. All rights reserved., PERGAMON-ELSEVIER SCIENCE LTD, English

Divergent electrochemical carboxylation of vinyl triflates: new electrochemical synthesis of phenyl-substituted alpha,beta-unsaturated carboxylic acids and aliphatic beta-keto carboxylic acids
H Senboku, Y Fujimura, H Kamekawa, M Tokuda, ELECTROCHIMICA ACTA, 45, 18, 2995, 3003, 2000
Electrochemical carboxylation of vinyl triflates using a magnesium anode, as a reactive metal electrode, was investigated. Alkyl-substituted vinyl triflates were electrolyzed in the presence of an atmospheric pressure of carbon dioxide to give beta-keto carboxylic acids as a sole products. On the other hand, electrochemical carboxylation of phenyl-substituted vinyl triflates gave alpha,beta-unsaturated carboxylic acids exclusively. These divergent electrochemical carboxylation resulted from chemoselective cleavage of O-S or C-O bond of vinyl triflate, which was affected by the presence or absence of phenyl substituents in the structure of starting vinyl triflates. (C) 2000 Elsevier Science Ltd. All rights reserved., PERGAMON-ELSEVIER SCIENCE LTD, English

Tandem cyclization of N-allylaminyl radicals: Stereoselective synthesis of 1,2,5-trisubstituted pyrrolizidines
H Senboku, Y Kajizuka, H Hasegawa, H Fujita, H Suginome, K Orito, M Tokuda, TETRAHEDRON, 55, 21, 6465, 6474, May 1999
Radical reaction of N-allylalk-4-enylaminyl radicals, generated from the corresponding N-chloroamines by treatment with Bu3SnH-AIBN in refluxing toluene, was carried out. Tandem cyclization of the resulting neutral aminyl radicals readily took place stereoselectively to give 1,2,5-trisubstituted pyrrolizidines and a pyrroloindole derivative as a sole product in good yields. The cyclization products contained only two stereoisomers in each reaction, indicating that both of the consecutive cyclizations proceeded in a stereoselective manner. (C) 1999 Elsevier Science Ltd. All rights reserved., PERGAMON-ELSEVIER SCIENCE LTD, English

New stereoselective synthesis of (+/-)-trans-2-butyl-5-heptyl-1-methylpyrrolidine, ant venom alkaloid, by aminyl radical cyclization
H Senboku, H Hasegawa, K Orito, M Tokuda, HETEROCYCLES, 50, 1, 333, 340, Jan. 1999
New synthesis of (+/-)-trans-2-butyl-5-heptyl-1-methylpyrrolidine (1), ant venom alkaloid, was achieved by the use of stereoselective cyclization of aminyl radicals. Thus, orthoester Claisen rearrangement of 1-hexen-3-ol (2) gave (E)-ethyl 4-octenoate (3). Reaction of ester (3) with 2-methylaminopyridine and AlCl3 afford ed the corresponding N-methyl-N-(2-pyridyl)amide (4), which was treated with heptylmagnesium iodide at -78 degrees C to give (E)-4-pentadecen-8-one (5). Reductive amination of ketone (5) with methylamine gave N-methyl-1-heptyl-4-octenylamine (6). Treatment of amine (6) with NCS in toluene gave the corresponding N-chloroamine (12), and successive heating under reflux with Bu3SnH and AIBN resulted in stereoselective cyclization of the aminyl radical to give (+/-)-trans-2-butyl-5-heptyl-1-methylpyrrolidine (1) in a 59% yield. Similarly, 1-nonen-3-ol (7) was converted into N-methyl-1-butyl-4-undecenylamine (11), which was subjected to the aminyl radical cyclization to give 1 in a 49% yield., PERGAMON-ELSEVIER SCIENCE LTD, English

New electrochemical carboxylation of vinyl triflates. Synthesis of beta-keto carboxylic acids
H Kamekawa, H Senboku, M Tokuda, TETRAHEDRON LETTERS, 39, 12, 1591, 1594, Mar. 1998
Electrochemical reduction of alicyclic vinyl triflates (1a-1e) in a DMF solution containing 0.1 M Bu4NBF4 under an atmospheric pressure of carbon dioxide with a platinum cathode and a magnesium anode resulted in the cleavage of an oxygen-sulfur bond of 1 to give the corresponding beta-keto carboxylic acids (2a-2e) in yields of 28-77%. (C) 1998 Elsevier Science Ltd. All rights reserved., PERGAMON-ELSEVIER SCIENCE LTD, English

New and convenient synthesis of 3-methylenepent-4-enoic acid by electrochemical carboxylation
M Tokuda, A Yoshikawa, H Suginome, H Senboku, SYNTHESIS-STUTTGART, (10),1143-1145, 10, 1143, &, Oct. 1997
Electrochemical carboxylation of 2-bromomethyl-1,4-dibromobut-2-ene (1) with atmospheric carbon dioxide in a DMF solution containing Bu4NI with a platinum cathode and a manganin or nickel anode gave 3-methylenepent-4-enoic acid (3) in 57 % yield. The acid 3 can be used as a diene in an aqueous intermolecular Diels-Alder reaction with dimethyl fumarate to give the adduct 7 in 67 % yield., GEORG THIEME VERLAG, English

Facile synthesis of aryl-substituted 2-alkenoic acids by electroreductive carboxylation of vinylic bromides using a magnesium anode
H Kamekawa, H Senboku, M Tokuda, ELECTROCHIMICA ACTA, 42, 13-14, 2117, 2123, 1997
Electrochemical carboxylation of phenyl-substituted vinylic bromides in the presence of atmospheric carbon dioxide using a platinum cathode and a magnesium anode gave the corresponding alpha,beta-unsaturated carboxylic acids in 63-92% isolated yields. A precursor of ibuprofen, 2-(pisobutylphenyl)propenoic acid, was readily obtained in a 93% yield by a similar electrochemical carboxylation of 1-bromo-1-(p-isobutylphenyl)ethene. Stereochemical studies showed that thermodynamically less stable Z-isomers were preferentially produced from either E- or Z-vinylic bromides in these electrochemical carboxylations. (C) 1997 Elsevier Science Ltd., PERGAMON-ELSEVIER SCIENCE LTD, English

Synthesis of alpha,beta-unsaturated carboxylic acids by nickel(II)-catalyzed electrochemical carboxylation of vinyl bromides
H Kamekawa, H Kudoh, H Senboku, M Tokuda, CHEMISTRY LETTERS, (9),917-918, 9, 917, 918, 1997
Electrochemical carboxylation of alkyl-substituted vinyl bromides (1a-1g) in the presence of 20 mol% of NiBr2.bpy under an atmospheric pressure of carbon dioxide with a platinum cathode and a magnesium anode gave the corresponding alpha,beta-unsaturated carboxylic acids (2a-2g) in yields of 53-82%., CHEMICAL SOC JAPAN, English

Photoinduced molecular transformations .159. Formation of some furonaphthyridinones by selective beta-scission of cyclobutanoxyl radicals generated from [2+2] photoadducts of 4-hydroxy-1-phenyl [1,8] naphthyridin-2(1H)-one with alkenes
H Senboku, M Takashima, M Suzuki, K Kobayashi, H Suginome, TETRAHEDRON, 52, 17, 6125, 6138, Apr. 1996
The [2+2] photoaddition of 4-hydroxy-1-phenyl[1,8]naphthyridin-2(1H)-one 7 with various alkenes in methanol gave regioselectively the corresponding head-to-tail adducts (8,9, and 11). The photolysis of the hypoiodites generated by the in situ reaction of the cyclobutanol adducts 8,9, and 11 with excess mercury(II) oxide-iodine reagent in benzene induced a regioselective scission of their non-ring junction bond of the corresponding alkoxyl radicals to give substituted 3,9-dihydro-9-phenylfuro[2,3-b][1,8]naphthyridin-4(2H)-one (12 and 15) and/or substituted 3,5-dihydro-5-phenylfuro[3,2-c][1,8]naphthyridin-4-(2H)-one (13,14, and 16). An unusual byproduct 12a was formed in the photolysis of the hypoiodite of the [2+2] photoadduct 8a of 4-hydroxy-1-phenyl[1,8]naphthyridin-2-(1H)-one with isobutene. (C) 1996 Elsevier Science Ltd., PERGAMON-ELSEVIER SCIENCE LTD, English

PHOTOINDUCED MOLECULAR-TRANSFORMATIONS .147. [2+2] PHOTOADDITION OF PROTECTED 4-HYDROXY-1(2H)-ISOQUINOLINONE WITH AN ELECTRON-DEFICIENT ALKENE AND THE FORMATION OF A 3,6-EPOXY-3,4,5,6-TETRAHYDRO-2-BENZAZOCIN-1(2H)-ONE VIA A BETA-SCISSION OF CYCLOBUTANOXYL RADICALS GENERATED FROM THE RESULTING PHOTOADDUCT
H SUGINOME, Y KAJIZUKA, M SUZUKI, H SENBOKU, K KOBAYASHI, HETEROCYCLES, 37, 1, 283, 288, Jan. 1994
The direct irradiation of 4-benzyloxycarbonyloxy-2-methyl-1(2H)-isoquinolinone gave a 1 to 1 ratio of two stereoisomers of [2+2] photoadducts in 97% yield. Removal of the protecting group from the adducts by hydrogenolysis gave the corresponding cyclobutanols, (1 alpha, 2a alpha, 8b alpha)-(+/-)-1-cyano-1,2a,3,8b-tetrahydro-8 b-hydroxy-3 -methylcyclobut[c]-isoquinolin-4(2H)-one and its (1 alpha, 2a beta, 8b beta)- isomer in 78 and 67% yields. The photolysis of the hypoiodite generated in situ from the (1 alpha, 2a alpha, 8b alpha)-(+/-)-cyclobutanol with mercury(II) oxide - iodine in benzene induced a regioselective beta-scission at the ring fusion bond of the cyclobutanoxyl radical to give 5-cyano-3,6-epoxy-3,4,5,6-tetrahydro-6-hydroxy-2-methyl-2- benzazocin-1(2H)-one in 76% yield. The cyano substituent and the amide nitrogen play a decisive role in directing the bond to be cleaved., PERGAMON-ELSEVIER SCIENCE LTD, English

Encyclopedia of Applied Electrochemistry　　　　　　　　　　　　　　　
SENBOKU Hisanori, Electrochemical Fixation of Carbon Dioxide (Cathodic Reduction in the Presence of Carbon Dioxide)
Springer Science+Business Media, New York, 2014

Transformation and Utilization of Carbon Dioxide　　　　　　　　　　　　　　　
SENBOKU Hisanori, Electrochemical Fixation of Carbon Dioxide
Springer-Verlag, Berlin Heidelberg, 2014

超臨界二酸化炭素中での有機電解合成　　　　　　　　　　　　　　　
新しい溶媒を用いた有機合成、S&T出版, 2013, 130-142

有機カルボン酸の高効率合成　　　　　　　　　　　　　　　
超臨界流体プロセスの実用化, 技術情報協会, 2000

Synthesis of β-Keto Acid by Electrochemical Carboxylation of Vinyl Triflates　　　　　　　　　　　　　　　
Novel Trends in Electroorganic Synthesis, ed. by Torii S., Springer-Verlag, Tokyo, 1998

Electrochemical Carboxylation of Several Organic Halides in Supercritical Carbon Dioxide　　　　　　　　　　　　　　　
Novel Trends in Electroorganic Synthesis, ed. by Torii S., Springer-Verlag, Tokyo, 1998

New and Convenient Synthesis of 3-Methylene-4-pentenoic Acid by Electrochemical Carboxylation　　　　　　　　　　　　　　　
Novel Trends in Electroorganic Synthesis, ed. by Torii S., Springer-Verlag, Tokyo, 1998

Synthesis of α,β-Unsaturated Carboxylic Acids by Electrochemical Carboxylation of Vinyl Bromides and Its application to the Synthesis of Anti-inflammatory Agents　　　　　　　　　　　　　　　
Novel Trends in Electroorganic Synthesis, ed. by Torii S., Springer-Verlag, Tokyo, 1998

二酸化炭素を炭素源とするβ－アミノ酸の金属フリーな環境調和型電解合成
科学研究費助成事業
01 Apr. 2022 - 31 Mar. 2025
仙北 久典
日本学術振興会, 基盤研究(C), 北海道大学, 22K05182

二酸化炭素を炭素源として用いる電子移動型極性変換によるマンデル酸の環境調和型合成
Apr. 2016 - Mar. 2019
仙北 久典
Principal investigator, Competitive research funding

電子移動還元反応を利用する二酸化炭素とアルコールからの増炭カルボン酸の一段階合成
科学研究費補助金（基盤研究(C)）
Jun. 2013 - Mar. 2016
仙北 久典
日本学術振興会, Principal investigator, Competitive research funding

Multiphase Reaction Medium Including Dense Phase Carbon Dioxide and Water for Rate Acceleration and Selectivity Control of Synthetic Organic Reactions
Grants-in-Aid for Scientific Research
2010 - 2012
ARAI Masahiko, FUJITA Shinichiro, SENBOKU Hisanori
Multiphase reaction media including dense phase carbon dioxide and/or water have been applied for hydrogenation reactions, photocatalytic reactions, and so on. The practical usefulness of those reactions was examined and the physical and chemical functions of carbon dioxide and water were investigated. The reactions studied include selective hydrogenation of nitriles to primary amines, hydrogenation of phenol, photocatalytic water splitting, and others. In situ high pressure Fourier transform infrared spectroscopy was used to examine the interactions between carbon dioxide and organic substrates and those between supported catalytic metal particles and reacting species (carbon monoxide formed from carbon dioxide and hydrogen, organic substrates, water). There were observed acceleration of reaction rate, modification of product selectivity, and/or suppression of catalyst deactivation for those reactions in the multiphase media. The chemical functions of carbon dioxide and water d pended on the chemical reactions examined.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 22360327

Umpolung using Electroorganic Reaction - Carbon-Carbon Bond Forming Reaction by the use of Sulfonates as a Nucleophile.
Grants-in-Aid for Scientific Research(基盤研究(C))
2003 - 2005
仙北 久典, Tsuyoshi FUKUHARA, 吉田 雅紀, 原 正治, 仙北 久典
Electrochemical reduction (ER) of 3-phenylpropyl tosylate gave 3-phenyl-1-propanol predominantly. On the other hand, a similar ER of 3-phenylpropyl mesylate in the presence of ketones, such as cyclohexanone, resulted in C-C bond forming reaction between mesylate and ketone to obtain the corresponding 1-(3-phenylpropyl)cycloalkanol in up to 30% yields. However, the yields of C-C bond forming reaction products could not be improved even though the reaction was carried out under various reaction conditions.We next tried ER of alkyl mesylates to the corresponding alkanes. A constant current ele...
Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(C), 北海道大学, Principal investigator, Competitive research funding, 15550082

マイクロウェーブ照射法による環境調和的な合成反応の開発
科学研究費補助金(萌芽的研究, 萌芽研究)
2001 - 2002
徳田 昌生, 仙北 久典, 折登 一彦, 黒野 暢仁
1.(E)-および(Z)-ハロゲン化ビニルの高効率・高立体選択的合成trans-α,β-不飽和カルボン酸の臭素化で得られるanti-2,3-ジブロモアルカン酸にDMF溶媒中トリエチルアミンを添加してマイクロ波を1分間照射すると、相当する(Z)-臭化ビニルが高効率かつ高立体選択的に合成されることをすでに報告した。今年度は、同一の出発原料であるanti-2,3-ジブロモアルカン酸を酢酸中1.2当量の酢酸銀を加えて1分間マイクロ波照射することによって、全く異なる異性体である(E)-臭化ビニルが高収率かつ高立体選択的に合成されるという、極めて興味深い結果を見出した。2.ハロゲン化ビニルの無溶媒合成反応の開発DMF溶媒中でのマイクロ波反応による(Z)-臭化ビニルの合成についてはすでに成功しているが、無溶媒でマイクロ波照射を行っても同様の合成反応が高効率で進行することを見出し、現在展開を図っている。3.クロスカップリング反応の開発anti-2,3-ジブロモアルカン酸のマイクロ波反応で(Z)-臭化ビニルを合成し、そのままone-potでPd触媒、CuIおよびフェニルアセチレンを加えてマイクロ波をさらに2分間照射すると,薗頭カップリングが進行し、相当するエンイン化合物が良好な収率で得られることを見出した。立体選択性の低下が現在のところ問題点である。
文部科学省, 萌芽的研究, 萌芽研究, 北海道大学, Coinvestigator not use grants, Competitive research funding, 13875171

アルケン類の電解ジカルボキシル化による1,2-ジカルボン酸の環境低負荷型合成
科学研究費補助金(奨励研究(A))
2000 - 2001
仙北 久典
研究計画に基づき以下の検討を行い、以下のような実績が得られた。1)シクロヘキセンなどの脂肪族アルケンの電解カルボキシル化については、種々検討を行ったが電解カルボキシル化は進行しなかった。しかしながら、1,3-シクロヘキサジエンなどの環状ジエンを用いるとジカルボキシル化反応が進行し、相当する2-シクロアルケン-1,4-ジカルボン酸を54〜93%の収率で得ることに成功した。さらに、ニッケル触媒を用いるβ-ブロモスチレンの電解ホモカップリング反応は高収率で進行すること、得られるフェニル置換ブタジエンの電解ジカルボキシル化も容易に進行すること、これらの2つの反応がワンポットで行えること等も明らかとした。2)超臨界二酸化炭素を反応媒体としてフェニル置換アルケン類の電解ジカルボキシル化を検討したところ、収率よく相当するジカルボン酸を得ることができ、有機溶媒を用いた反応と比較してもほぼ同様の収率でジカルボン酸が得られることを明らかとした。3)特異な骨格としてメチレンシクロプロパン構造を有するビシクロ[n.1.0]アルキリデン誘導体のアルケン部位に電子吸引性基を有する基質についてジカルボキシル化反応を検討した。その結果、カルボキシル化は容易に進行し、1分子もしくは2分子の二酸化炭素を固定化したモノカルボン酸及びジカルボン酸が基質選択的に生成した。また、得られたカルボン酸はすべてexo-異性体...
文部科学省, 奨励研究(A), 北海道大学, Principal investigator, Competitive research funding, 12750753

Development of Various Cross-coupling Reactions in New Media for the Electron-Transfer Reactions
Grants-in-Aid for Scientific Research(基盤研究(B))
1999 - 2001
Masao TOKUDA, 仙北 久典, 折登 一彦
The purpose of this study is to develop new media for the electron-transfer reactions and to use these media in cross-coupling reactions of various organic halides with aryl halides or in selective carbon-carbon forming reactions. In order to achieve efficient cross-coupling reactions, two media for the electron-transfer reactions were employed in this study. One is to use highly reactive zinc which can readily be prepared by electrolysis. Another medium is the electrochemical reaction system using a reactive-metal anode such as magnesium or zinc.We found that the electrolysis of a DMF solu...
Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(B), 北海道大学, Coinvestigator not use grants, Competitive research funding, 11450342

Synthesis of Anti-inflammatory Agents by Electrochemical Fixation of Carbon Dioxide
Grants-in-Aid for Scientific Research(基盤研究(B))
1998 - 2000
Masao TOKUDA, 佐々木 〓美, 仙北 久典, 折登 一彦, 佐々木 皇美
1. Synthesis of Anti-inflammatory Agents and Their Precursors(1)Electrochemical carboxylation of vinyl halides -2-Aryl-2-propenoic acids were prepared in high yields by electrolysis of the corresponding aryl-substituted vinyl bromides in DMF in the presence of atmospheric pressure of carbon dioxide with a platinum cathode and a magnesium anode. 2-Aryl-2-propenoic acids, precursors of various anti-inflammatory agents such as ibuprofen, naproxen, and ketoprofen, were actually prepared in high yields by using this electrochemical carboylation and can readily be transformed into anti-inflammato...
Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(B), 北海道大学, Coinvestigator not use grants, Competitive research funding, 10555314

超臨界二酸化炭素を用いる電解カルボキシル化反応の開発と抗炎症剤合成への応用
科学研究費補助金(奨励研究(A))
1998 - 1999
仙北 久典
昨年度の研究では、少量のアセトニトリルを共溶媒として用いると超臨界二酸化炭素中(反応温度40℃、二酸化炭素圧力80Kg/cm^2)でも電解に十分な通電が得られることを見出し、本反応を用いて抗炎症剤イブプロフェン[2-(4-イソブチルフェニル)プロピオン酸]の合成にも成功した。今年度はさらに様々な出発物質から種々の抗炎症剤ならびにそれらの前駆体の合成を行った。相当する塩化ベンジルまたは芳香族置換臭化ビニルを基質として用いる超臨界二酸化炭素中での電解カルボキシル化では、抗炎症剤であるイブプロフェン、ナプロキセン、シクロプロフェンならびにそれらの光学活性体の前駆体を良好な収率で得ることができた。一方、相当するアリールメチルケトンを基質として同様の反応を行うと2-アリールプロパン酸構造を有する抗炎症剤の光学活性体の前駆体であるα-ヒドロキシカルボン酸を高収率で合成することができた。なかでも、ロキソプロフェンはその分子内に脂肪族ケトン構造を有しており、共存するケトンのうち芳香族ケトン部のみを化学選択的にカルボキシル化できるのは電解反応の特長を生かしたものといえる。これらの結果は、日本化学会題78春季年会において発表予定であり、今後学術論文として投稿する予定である。一方、臭化ビニルの類縁体としてビニルトリフラートがあげられる。含フッ素化合物は超臨界二酸化炭素に高い溶解性を示すことが知られ...
文部科学省, 奨励研究(A), 北海道大学, Principal investigator, Competitive research funding, 10750614

環境調和型共有結合生成反応-超臨界流体およびKを溶媒とする新規反応場の開発
科学研究費補助金(特定領域研究(A))
1998 - 1998
徳田 昌生, 高橋 憲司, 仙北 久典
1.超臨界二酸化炭素中での電解カルボキシル化白金陰極、マグネシウム陽極を取り付けた高圧反応容器に支持電解質としてBu_4NBF_4、共溶媒として少量のアセトニトリル(10ml:155mlの反応容器に対して6vol%)を加え、二酸化炭素の臨界点以上の反応条件(40℃,80Kg/cm^2)で電解することによって、電解力ルボキシル化が可能となることを見出した。超臨界二酸化炭素中での電解によるカルボン酸の合成は本研究が世界で最初の例である。さまざまな置換ハロゲン化アリールを電解すると相当するアレーンカルボン酸が高収率で得られた。例えば、1-および2-クロロナフタレンからナフタレン手およびナフタレン-2-カルボン酸をそれぞれ92%および83%の収率で得ることができた。また、ハロゲン化ベンジル類を同様な条件下電解することによって置換フェニル酢酸を高収率で合成することができた。現在、さらにさまざまな基質を用いて電解カルボキシル化を検討している。2.超臨界二酸化炭素を用いる抗炎症剤の合成1-クロロ-1-(4-イソブチルフェニル)エタンおよび1-クロロ-(6-メトキシナフチル)エタンを超臨界二酸化炭素中上記の条件で電解することによって、抗炎症剤であるイブプロフェンおよびナプロキセンをそれぞれ79%および74%の収率で合成することに成功した。3.電子移動反応における超臨界流体の特性に関する研究超...
文部科学省, 特定領域研究(A), 北海道大学, Coinvestigator not use grants, Competitive research funding, 10132202

超臨界二酸化炭素を用いる有機電解合成
科学研究費補助金(萌芽的研究)
1997 - 1998
徳田 昌生, 佐々木 皇美, 仙北 久典
1. 超臨界二酸化炭素中での電解カルボキシル化平成9年度の研究において、白金陰極、マグネシウム陽極を取り付けた高圧反応容器に支持電解質としてBu_4NBF_4、共溶媒として少量のアセトニトリル(10ml;155mlの反応容器に対して6vol%)を加え、臨界点以上の反応条件(40℃,80Kg/cm^2)にすると電解が可能となることを見出した。今年度は1-プロモナフタレンを基質として用い、反応条件についてさらに詳細な検討を行った。その結果、基質1mmolに対して5mmolのBUu4NBF_4の支持電解質を用い、5F/molの通電量で電解することによって95%の収率でナフタレン-1-カルボン酸を得ることができた。共溶媒については3mlまで減らしても約70%の収率でカルボン酸が得られることを見出した。超臨界二酸化炭素中での電解によるカルボン酸の合成は本研究が世界で最初の例である。2. 芳香族カルボン酸の合成少量のアセトニトリルを共溶媒とし超臨界二酸化炭素中上記の条件下1-クロロナフタレンを20mA/cm^2の定電流で電解することによって、ナフタレン-1-カルボン酸を92%の高収率で得ることができた。さまざまなハロゲン化アリールを同様の条件下電解することによって括弧内に示す収率でそれぞれ相当するカルボン酸を合成することができた:2-クロロナフタレン(83%)、2-ブロモナフタレン(79...
文部科学省, 萌芽的研究, 北海道大学, Coinvestigator not use grants, Competitive research funding, 09875218

Electrochemical Fixation of Carbon Dioxide by the Use of Fluidized Electrochemical Cell-Synthesis of Useful Organic Carboxylic Acids
Grants-in-Aid for Scientific Research(試験研究(B), 基盤研究(A))
1995 - 1997
Masao TOKUDA, 佐々木 皇美, 千葉 忠俊, 仙北 久典, 折登 一彦
The purpose of this research project is to develop an efficient preparation method of synthetically useful carboxylic acids by electrochemical fixation of carbon dioxide to organic substrates using fluidized electrochemical cell.1.Synthesis of Unsaturated Carboxylic Acids by Electrochemical Carboxylation Using a Reactive-metal Anode-Electrochemical carboxylation of allylic halides, propargylic halides, vinyl halides, vinyl triflates, and 1,4-dibromo-2-bromomethyl-2-butene in the presence of atmospheric carbon dioxide using a reactive-metal anode gave, respectively, alpha, beta-unsaturated a...
Ministry of Education, Culture, Sports, Science and Technology, 試験研究(B), 基盤研究(A), 北海道大学, Coinvestigator not use grants, Competitive research funding, 07555580

電解調製の活性亜鉛を用いる新しい有機反応の開発
科学研究費補助金(重点領域研究)
1995 - 1995
徳田 昌生, 仙北 久典, 折登 一彦
1.電解調製の活性亜鉛のキャラクタリゼーションDMF溶液中白金陰極-亜鉛陽極を用いて電解することにより活性な亜鉛が簡便に調製できることをすでに見出しているが、この電解調製亜鉛(EGZn)について走査型電子顕微鏡(FE-SEM)、X線回折、光電子分光分析(XPS)、蛍光X線分析および表面積測定などによってキャラクタリゼーションを行った。その結果、EGZnは0.1μ以下の亜鉛微粒子の凝集体で、PbやClあるいはN原子を含まない純度の高い結晶であり、その表面積は他の市販金属亜鉛より数10〜数100倍大きいことを明らかにすることができた。この極めて大きな表面積がEGZnの高活性の原因のひとつであることが判明した。2.電解調製活性亜鉛(EGZn)を用いる有機合成反応イソプレンから容易に合成できる2-ブロモメチル-1,4-ジブロモ-2-ブテン(BMDBB)をEGZnの存在下アルデヒドやケトンと反応させることにより温和な条件でイソプレニル化アルコールが高収率で得られることを見出している。この条件下において二酸化炭素との反応は進行しなかったが、常圧の二酸化炭素の存在下BMDBBを電解還元することによりイソプレンカルボン酸を合成することができた。一方、EGZnの存在下ハロゲン化アリルをケトンやアルデヒドあるいは酸無水物と反応させることにより温和な条件下でアリル化を進行させることができ、それぞれ...
文部科学省, 重点領域研究, 北海道大学, Coinvestigator not use grants, Competitive research funding, 07216201

複素環化合物の新規合成法の開発と生理活性分子合成への応用
科学研究費補助金(奨励研究(A))
1994 - 1994
仙北 久典
研究計画に基づき、まず文献既知である4-ヒドロキシ-2-フェニル[1,8]ナフチリジン-2(1H)-オンとイソブテンをメタノール中500W高圧水銀灯によりPyrexフィルターを通して光照射し、head to headの位置選択的[2+2]光シクロ付加反応によりシクロブタノール誘導体を高収率で得た。エチルビニルエーテル、1-メトキシシクロヘキセン、酢酸イソプロペニルを用いた場合も同様の付加反応により相当するシクロブタノール誘導体を50-80%の収率で得た。次に、得られたシクロブタノールをベンゼン中、各3等量の酸化水銀およびヨウ素存在下、Pyrexフィルターを通し光照射を行った。その結果、発生したアルコキシルラジカルの炭素-炭素結合での位置選択的β-開裂反応によりフロナフチリジンが38-74%の収率で生成することを見出した。イソブテンとの付加体であるシクロブタノールからはフロ[2,3-b][1,8]ナフチリジン-4[2H]-オン誘導体のみが得られた。一方、エチルビニルエーテルおよび1-メトキシシクロヘキセンとの付加体であるシクロブタノールからは、フロ[3,2-c][1,8]ナフチリジン-4[2H]-オンのみが得られ、酢酸イソプロペニルとの付加体であるシクロブタノールからは両方のフロナフチリジン誘導体が得られた。フロナフチリジン骨格を有する化合物は抗アレルギー性・抗炎症性・鎮咳作用...
文部科学省, 奨励研究(A), 北海道大学, Principal investigator, Competitive research funding, 06750879

Development of New Selective Organic Processes and Their Application to the Synthesis of Biologically-active Molecules
Grants-in-Aid for Scientific Research(一般研究(A))
1991 - 1993
Hiroshi SUGINOME, 小林 和裕, 折登 一彦, 徳田 昌生, 仙北 久典
New Photoadditions of quinones leading to heterocyclic quinones. -A one-step formation of heterocyclic quinones by a new regioselective [3+2] photoaddition of 2-hydroxy, 2-amino-, and 2-mercapto-1,4-naphthoquinones with a variety of alkenes, alkyns and naphthol was found. The new [3+2] photoaddition reaction was then applied to the synthesis of maturinone. New photoacylation and alkylation of 2-arylamino-, and 2-alkylaminonaphtho quinones were also devised.Development of new methods for the transformations based on selective fragmentation of alkoxyl radicals.-Several new methods were devise...
Ministry of Education, Culture, Sports, Science and Technology, 一般研究(A), 北海道大学, Coinvestigator not use grants, Competitive research funding, 03403017

Deveropment of synthetic organic reactions by using hypervalent iodine compounds　　　　　　　　　　　　　　　
Competitive research funding

Synthesis of Carboxylic Acid by the Electrochemical Carboxylation using A Reactive-metal Anode.　　　　　　　　　　　　　　　
Competitive research funding

Electro-organic synthesis　　　　　　　　　　　　　　　
Competitive research funding

置換スチレン誘導体　　　　　　　　　　　　　　　
Patent right
JP2001081066

Substituted Styrene Derivative　　　　　　　　　　　　　　　
Patent right
JP2001081066