Sawamura Masaya
| Faculty of Science Chemistry Organic and Biological Chemistry | Professor |
| Office of Health and Safety | Professor |
| Faculty of Engineering | Professor |
| Creative Research Institution Institute for Chemical Reaction Design and Discovery | Professor |
Last Updated :2024/12/06
■Researcher basic information
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■Career
Career
- 2001 - Present
- 北海道大学 教授 - 2001 - Present
- Hokkaido University Professor - 2019 - 2023
Hokkaido University, Institute for Chemical Reaction Design and Discovery (WPI-ICReDD, Professor - Apr. 2016 - Mar. 2022
Hokkaido University, Distinguished Professor - 1997 - 2001
The University of Tokyo - 1997 - 2001
The University of Tokyo, Associate Professor - 1996 - 1997
The University of Tokyo - 1996 - 1997
The University of Tokyo, Lecturer - 1995 - 1996
The University of Tokyo - 1995 - 1996
The University of Tokyo, Research Assistant - 1995 - 1995
- 東京工業大学 助手 - 1995 - 1995
- Tokyo Institute of Technology, Research Assistant - 1989 - 1995
京都大学 助手 - 1989 - 1995
Kyoto University, Research Assistant
Educational Background
Position History
■Research activity information
Awards
- May 2022, 日本産業衛生学会, 第１３回GP奨励賞
多数の作業場を抱える組織における効果的な職場巡視のための連携体制づくり〜大学の事例を通して〜
川上貴教、平井克美、澤村正也 - Apr. 2021, Ministry of Education, Culture, Sports, Science and Technology, The Commendation for Science and Technology by the Minister of Education, Culture, Sports, Science and Technology-Awards for Science and Technology-Research Category
遷移金属有機合成触媒の設計と不斉制御の研究
Masaya Sawamura - Feb. 2020, 北海道大学, 北海道大学教育研究総長賞
澤村正也 - Feb. 2019, The Society of Synthetic Organic Chemistry, Japan, Synthetic Organic Chemistry Award
Development of Carbon-Carbon Bond Forming Asymmetric Copper-Catalyzed Reactions
SAWAMURA Masaya - Mar. 2018, 根岸賞
澤村 正也 - Jan. 2017, 名古屋シルバーメダル
澤村 正也 - Feb. 2015, 有機合成化学協会 日産化学・有機合成新反応／手法賞
澤村 正也 - Mar. 2014, 北海道大学研究総長賞
澤村 正也 - Mar. 2012, 日本化学会学術賞
澤村 正也 - Mar. 1996, 日本化学会進歩賞
Japan - Feb. 1989, 有機合成化学協会 「研究企画賞」
Japan
Papers
- Roles of Divinylbenzene Co‐Cross‐Linker in a Threefold Cross‐Linked Polystyrene‐Phosphine Hybrid Monolith: Impact of Cross‐Linking Degree on Catalytic Performance
Hikaru Matsumoto, Yu Hoshino, Tomohiro Iwai, Masaya Sawamura, Yoshiko Miura
European Journal of Organic Chemistry, Wiley, 26 Sep. 2024
Scientific journal, Continuous‐flow organic transformations using immobilized catalysts are crucial for green and sustainable chemistry. Cross‐linked polymer ligands offer high stability, ease of recovery through filtration, and thus enhance performance in continuous‐flow reactions via transition‐metal catalysis. Additionally, the cross‐linking structure of the polymer support creates a unique reaction platform that controls the coordination behavior of the supported ligands and stabilizes the metal catalysts. However, insights into the material‐based design for preparing highly active and durable immobilized metal catalysts are still limited. In this report, we propose a straightforward approach to boost both selective mono‐coordination and effective stabilization of metal complexes. We developed threefold cross‐linked polystyrene‐triphenylphosphine hybrid monoliths with cross‐linking structures adjusted by varying the content of divinylbenzene as co‐cross‐linker. The coordination behaviors and metal‐support interactions of these monoliths were evaluated, highlighting the importance of co‐cross‐linker content in site‐isolating phosphine units and stabilizing metal centers via arene‐metal interactions on the polystyrene network. By optimizing the cross‐linking structure, the monolith catalysts demonstrated exceptionally high catalytic activity and durability in Pd‐catalyzed C‐Cl transformations, such as Suzuki‐Miyaura cross‐couplings and Buchwald‐Hartwig aminations in continuous flow. This underscores the utility of our monolith system in challenging transition‐metal catalysis. - Boron-Catalyzed Michael Reaction of Donor–Acceptor Carboxylic Acid Pairs Enabling Direct Synthesis of 1,5-Dicarboxylic Acids
Yukiho Yoshida, Masaya Sawamura, Yohei Shimizu
Organic Letters, 26, 26, 5425, 5429, American Chemical Society (ACS), 19 Jun. 2024
Scientific journal - Gold‐Zinc Co‐Catalyzed Alkynoate Hydrocarboxylation with N‐Protected Amino Acids for Preparation of Storable Acylating Reagents and Racemization‐Free Peptide Synthesis
Ayaka Sakurada, Miyu Sato, Kosuke Higashida, Masaya Sawamura
Advanced Synthesis & Catalysis, Wiley, 15 May 2024
Scientific journal, Abstract
Hydrocarboxylation of methyl 2‐octynoate, a chemical commercially available at a low cost, with N‐protected amino acids was developed with a gold‐zinc cooperative catalyst constructed with a 5‐[ (2,2′‐bipyridin)‐5‐yl]imidazo[1,5‐a]pyridin‐3‐ylidene to prepare α‐methoxycarbonyl enol esters as acylating reagents. The α‐methoxycarbonyl enol esters were isolable through silica‐gel column chromatography and storable without precautions regarding moisture. Acylation of free amines with the α‐methoxycarbonyl enol esters proceeded without epimerization of the stereogenic center derived from the enol esters, affording analytically pure dipeptide compounds through filtration and hexane‐washing. - Continuous‐Flow Catalysis Using Phosphine‐Metal Complexes on Porous Polymers: Designing Ligands, Pores, and Reactors
Hikaru Matsumoto, Tomohiro Iwai, Masaya Sawamura, Yoshiko Miura
ChemPlusChem, Wiley, 28 Mar. 2024
Scientific journal, Continuous‐flow syntheses using immobilized catalysts can offer efficient chemical processes with easy separation and purification. In particular, porous polymers have gained significant interests for their applications to catalytic systems in the field of organic chemistry. The porous polymers are recognized for their large surface area, high chemical stability, facile modulation of surface chemistry, and cost‐effectiveness. It is crucial to immobilize transition‐metal catalysts due to their difficult separation and high toxicity. Supported phosphine ligands represent a noteworthy system for the effective immobilization of metal catalysts and modulation of catalytic properties. Researchers have been actively pursuing strategies involving phosphine‐metal complexes supported on porous polymers, aiming for high activities, durabilities, selectivities, and applicability to continuous‐flow systems. This review provides a concise overview of phosphine‐metal complexes supported on porous polymers for continuous‐flow catalytic reactions. Polymer catalysts are categorized based on pore sizes, including micro‐, meso‐, and macroporous polymers. The characteristics of these porous polymers are explored concerning their efficiency in immobilized catalysis and continuous‐flow systems. - 20.2.1.8.15 Synthesis of Carboxylic Acids with Retention of the Functional Group (Update 2024)
M. Sawamura, Y. Shimizu
Knowledge Updates 2024/2, Georg Thieme Verlag KG, 2024
In book, Abstract
Carboxylic acids are readily available feedstock materials, and are also found in natural products, pharmaceuticals, agrochemicals, and other biologically active compounds. Hence, efficient methods to transform carboxylic acids into other value-added compounds is of great importance. This review is an update to Science of Synthesis Section 20.2.1.8 on the synthesis of carboxylic acids with “retention of the functional group”. The main focus of this review is placed on asymmetric reactions and catalytic reactions, along with practical stoichiometric reactions, reported in the period 2010–2022. The transformations discussed include α-functionalizations, conjugate additions, and C(sp2)—H as well as C(sp3)—H functionalizations. - The Aldol Reaction: Group III Enolates
Masaya Sawamura, Yohei Shimizu
Reference Module in Chemistry, Molecular Sciences and Chemical Engineering, Elsevier, 2024
In book - Sheltering Mono-P-Ligated Metal Complexes in Porous Polystyrene Monolith: Effect of Aryl Pendant Stabilizers on Catalytic Durability.
Hikaru Matsumoto, Yu Hoshino, Tomohiro Iwai, Masaya Sawamura, Yoshiko Miura
Chemistry (Weinheim an der Bergstrasse, Germany), 29, 55, e202301847, 02 Oct. 2023, [International Magazine]
English, Scientific journal, Metal centers that can generate coordinatively unsaturated metals in accessible and stable states have been developed using synthetic polymers with sophisticated ligand and scaffold designs, which required synthetic efforts. Herein, we report a simple and direct strategy for producing polymer-supported phosphine-metal complexes, which stabilizes mono-P-ligated metals by modulating the electronic properties of the aryl pendant groups in the polymer platform. A three-fold vinylated PPh3 was copolymerized with a styrene derivative and a cross-linker to produce a porous polystyrene-phosphine hybrid monolith. Based on the Hammett substituent constants, the electronic properties of styrene derivatives were modulated and incorporated into the polystyrene backbone to stabilize the mono-P-ligated Pd complex via Pd-arene interactions. Through NMR, TEM, and comparative catalytic studies, the polystyrene-phosphine hybrid, which induces selective mono-P-ligation and moderate Pd-arene interactions, demonstrated high catalytic durability for the cross-coupling of chloroarenes under continuous-flow conditions. - Photocatalytic 1,2-Phosphorus-Migrative [3 + 2] Cycloaddition of Tri(t-butyl)phosphine with Terminal Alkynes
Yusuke Masuda, Daichi Ikeshita, Kosuke Higashida, Masaki Yoshida, Naoki Ishida, Masahiro Murakami, Masaya Sawamura
Journal of the American Chemical Society, American Chemical Society (ACS), 21 Aug. 2023
Scientific journal - Dimetal‐Binding Scaffold 2‐(Pyridin‐2‐yl)imidazo [1,5‐b]pyridazine‐7‐ylidene: Synthesis of Trinuclear Heterobimetallic Complexes Involving Gold‐Metal Interactions
Akito Kitabayashi, Yuriko Ono, Tetsuya Taketsugu, Masaya Sawamura, Kosuke Higashida
Chemistry – A European Journal, Wiley, 09 Aug. 2023
Scientific journal, Abstract
As a dimetal‐binding rigid scaffold, 2‐(pyridin‐2‐yl)imidazo[1,5‐b]pyridazine‐7‐ylidene was introduced. The scaffold was first converted into a meridional Au,N,N‐tridentate ligand through binding of a Au(I)Cl moiety at the carbene center. The Au(I) center and the N,N‐chelating moiety were expected to function as metallophilic and 4e‐σ‐donative interaction sites, respectively, in the binding of the second metal center. In this manner, various trinuclear heterobimetallic complexes were synthesized with different 3d‐metal sources, such as cationic CuI, CuII, NiII, and CoII salts. SC‐XRD analysis showed that the mono‐3d‐metal di‐gold(I) trinuclear heterobimetallic complexes were constructed through gold(I)‐metal interactions. Metallophilic interactions were also investigated by quantum chemical calculations including the AIM and IGMH methods. - Gold‐Zinc Cooperative Catalysis for Seven‐exo‐dig Hydrocarboxylation of Internal Alkynes
Miyu Sato, Vishal Kumar Rawat, Kosuke Higashida, Masaya Sawamura
Chemistry – A European Journal, Wiley, 20 Jul. 2023
Scientific journal - Visible-Light-Induced Aminochlorination of Alkenes
Emna Mejri, Kosuke Higashida, Yuta Kondo, Anna Nawachi, Hiroyuki Morimoto, Takashi Ohshima, Masaya Sawamura, Yohei Shimizu
Organic Letters, American Chemical Society (ACS), 08 Jun. 2023
Scientific journal - Direct α-Trifluoromethylthiolation of Carboxylic Acids Enabled by Boron Catalysis
Kai Sun, Chung-Yang Dennis Huang, Masaya Sawamura, Yohei Shimizu
Synlett, Georg Thieme Verlag KG, 11 Apr. 2023, [Peer-reviewed], [Invited]
Scientific journal, A boron-catalyzed direct α-trifluoromethylthiolation of carboxylic acids was developed. Catalytically generated boron enediolates reacts with electrophilic SCF3 reagent, N-SCF3-phthalimide, to provide α-SCF3 carboxylic acids without the need of substrate pre-activation. The method is applicable to direct modification of bioactive carboxylic acids. Data science analyses provided suitable models for substrate classification as well as yield prediction. - Sequence-selective three-component reactions of alkyltrifluoroborates with α,β-unsaturated carbonyl compounds and vinylphosphonium salts
Masaki Yoshida, Masaya Sawamura, Yusuke Masuda
Organic Chemistry Frontiers, 10, 14, 3654, 3661, Royal Society of Chemistry (RSC), 2023
Scientific journal, A photocatalytic three-component reaction of alkyltrifluoroborates with two electron-deficient alkenes proceeds in a sequence-selective manner, which can be followed by Wittig olefination to afford γ,δ-unsaturated ketones and esters. - Boron Catalysis in the Transformation of Carboxylic Acids and Carboxylic Acid Derivatives
Masaya Sawamura, Yohei Shimizu
European Journal of Organic Chemistry, Wiley, 15 Dec. 2022, [Peer-reviewed], [Invited], [Lead author]
Scientific journal - Nickel-Catalyzed Defluorophosphonylation of Aryl Fluorides
Zhensheng You, Yusuke Masuda, Tomohiro Iwai, Kosuke Higashida, Masaya Sawamura
The Journal of Organic Chemistry, 87, 21, 14731, 14737, American Chemical Society (ACS), 18 Oct. 2022, [Peer-reviewed], [Last author, Corresponding author]
Scientific journal - Photoinduced Alcoholic α‐C−H Bond Anti‐Markovnikov Addition to Vinylphosphonium Bromides Followed by Wittig Olefination: Two‐Step Protocol for α‐C−H Allylic Alkylation of Alcohols
Masaki Yoshida, Masaya Sawamura, Yusuke Masuda
ChemCatChem, 20 Sep. 2022, [Peer-reviewed], [Invited], [Corresponding author]
Scientific journal - Silver‐Catalyzed Asymmetric Aldol Reaction of Isocyanoacetic Acid Derivatives Enabled by Cooperative Participation of Classical and Nonclassical Hydrogen Bonds
Satoshi Sakai, Akane Fujioka, Koji Imai, Kei Uchiyama, Yohei Shimizu, Kosuke Higashida, Masaya Sawamura
Advanced Synthesis & Catalysis, 364, 14, 2333, 2339, Wiley, 19 Jul. 2022, [Peer-reviewed], [Last author, Corresponding author]
Scientific journal - Construction of Heterobimetallic Catalytic Scaffold with a Carbene-Bipyridine Ligand: Gold–Zinc Two-Metal Catalysis for Intermolecular Addition of O-Nucleophiles to Nonactivated Alkynes
Vishal Kumar Rawat, Kosuke Higashida, Masaya Sawamura
ACS Catalysis, 12, 14, 8325, 8330, American Chemical Society (ACS), 15 Jul. 2022, [Peer-reviewed], [Last author, Corresponding author]
Scientific journal - Insights into the Mechanism of Enantioselective Copper‐Catalyzed Ring‐Opening Allylic Alkylation of Cyclopropanols
Akito Kitabayashi, Sho Mizushima, Kosuke Higashida, Yuto Yasuda, Yohei Shimizu, Masaya Sawamura
Advanced Synthesis & Catalysis, 364, 11, 1855, 1862, Wiley, 07 Jun. 2022, [Peer-reviewed], [Last author, Corresponding author]
Scientific journal - Photoinduced Copper-Catalyzed Asymmetric Acylation of Allylic Phosphates with Acylsilanes
Yusuke Ueda, Yusuke Masuda, Tomohiro Iwai, Keisuke Imaeda, Hiroki Takeuchi, Kosei Ueno, Min Gao, Jun-ya Hasegawa, Masaya Sawamura
Journal of the American Chemical Society, 144, 5, 2218, 2224, American Chemical Society (ACS), 06 Jan. 2022, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal - Visible Light-Induced Reductive Allylation of Aldehydes by Umpolung Approach
Ibuki Tanaka, Masaya Sawamura, Yohei Shimizu
Organic Letters, 24, 2, 520, 524, American Chemical Society (ACS), Dec. 2021, [Peer-reviewed], [Corresponding author]
English, Scientific journal - Synthesis of C,N,N-Cyclometalated Gold(III) Complexes with Anionic Amide Ligands
Ryotaro Niizeki, Kosuke Higashida, Emna Mejri, Masaya Sawamura, Yohei Shimizu
Synlett, 33, 3, 282, 292, Georg Thieme Verlag KG, 19 Oct. 2021, [Peer-reviewed], [Corresponding author]
English, Scientific journal, A series of neutral C,N,N Au(III) complexes was synthesized with N-(8-quinolinyl)benzamide derivatives and chiral N-(2-(oxazolin-2-yl)phenyl)benzamide derivatives. This convenient synthesis method for amide ligands as well as an operationally simple complexation by direct C-H auration permitted changes to both the steric and electronic properties of the Au(III) complexes for promoting catalytic three-component coupling of an aldehyde, an amine, and an alkyne. - Access to Indole-Fused Benzannulated Medium-Sized Rings through a Gold(I)-Catalyzed Cascade Cyclization of Azido-Alkynes
Luca C. Greiner, Shinsuke Inuki, Norihito Arichi, Shinya Oishi, Rikito Suzuki, Tomohiro Iwai, Masaya Sawamura, A. Stephen K. Hashmi, Hiroaki Ohno
Chemistry - A European Journal, 27, 51, 12992, 12997, John Wiley and Sons Inc, 09 Sep. 2021
English, Scientific journal, Because benzannulated and indole-fused medium-sized rings are found in many bioactive compounds, combining these fragments might lead to unexplored areas of biologically relevant and uncovered chemical space. Herein is shown that α-imino gold carbene chemistry can play an important role in solving the difficulty in the formation of medium-sized rings. Namely, phenylene-tethered azido-alkynes undergo arylative cyclization through the formation of a gold carbene intermediate to afford benzannulated indole-fused medium-sized tetracycles. The reactions allow a range of different aryl substitution patterns and efficient access to these otherwise difficult-to-obtain medium-sized rings. This study also demonstrates the feasibility of the semihollow-shaped C-dtbm ligand for the construction of a nine-membered ring. - Front Cover: Access to Indole‐Fused Benzannulated Medium‐Sized Rings through a Gold(I)‐Catalyzed Cascade Cyclization of Azido‐Alkynes (Chem. Eur. J. 51/2021)
Luca C. Greiner, Shinsuke Inuki, Norihito Arichi, Shinya Oishi, Rikito Suzuki, Tomohiro Iwai, Masaya Sawamura, A. Stephen K. Hashmi, Hiroaki Ohno
Chemistry – A European Journal, 27, 51, 12917, 12917, Wiley, 09 Sep. 2021
Scientific journal - Access to Indole‐Fused Benzannulated Medium‐Sized Rings through a Gold(I)‐Catalyzed Cascade Cyclization of Azido‐Alkynes
Luca C. Greiner, Shinsuke Inuki, Norihito Arichi, Shinya Oishi, Rikito Suzuki, Tomohiro Iwai, Masaya Sawamura, A. Stephen K. Hashmi, Hiroaki Ohno
Chemistry – A European Journal, 27, 51, 12992, 12997, Wiley, 09 Sep. 2021, [Peer-reviewed], [Invited], [International Magazine]
English, Scientific journal, Because benzannulated and indole-fused medium-sized rings are found in many bioactive compounds, combining these fragments might lead to unexplored areas of biologically relevant and uncovered chemical space. Herein is shown that α-imino gold carbene chemistry can play an important role in solving the difficulty in the formation of medium-sized rings. Namely, phenylene-tethered azido-alkynes undergo arylative cyclization through the formation of a gold carbene intermediate to afford benzannulated indole-fused medium-sized tetracycles. The reactions allow a range of different aryl substitution patterns and efficient access to these otherwise difficult-to-obtain medium-sized rings. This study also demonstrates the feasibility of the semihollow-shaped C-dtbm ligand for the construction of a nine-membered ring. - Visible-Light-Driven α-Allylation of Carboxylic Acids
Kai Sun, Masato Ueno, Keisuke Imaeda, Kosei Ueno, Masaya Sawamura, Yohei Shimizu
ACS Catalysis, 11, 15, 9722, 9728, American Chemical Society (ACS), 06 Aug. 2021, [Peer-reviewed], [Corresponding author]
Scientific journal - Construction of Medium-Sized Rings by Gold Catalysis
Ronald L. Reyes, Tomohiro Iwai, Masaya Sawamura
Chemical Reviews, 121, 14, 8926, 8947, American Chemical Society (ACS), 28 Jul. 2021, [Peer-reviewed], [Invited], [Last author, Corresponding author]
Scientific journal - A Hollow-shaped Caged Triarylphosphine: Synthesis, Characterization and Applications to Gold(I)-catalyzed 1,8-Enyne Cycloisomerization
Tomohiro Iwai, Yuto Goto, Zhensheng You, Masaya Sawamura
Chemistry Letters, 50, 6, 1236, 1239, The Chemical Society of Japan, 05 Jun. 2021, [Peer-reviewed], [Last author, Corresponding author]
Scientific journal - Nickel-Catalyzed Homocoupling of Aryl Ethers with Magnesium Anthracene Reductant
Kosuke Higashida, Masaya Sawamura, Vishal Kumar Rawat
Synthesis, Georg Thieme Verlag KG, 17 May 2021, [Peer-reviewed], [Invited], [Last author, Corresponding author]
Scientific journal,Abstract Nickel-catalyzed reductive homocoupling of aryl ethers has been achieved with Mg(anthracene)(thf)3 as a readily available low-cost reductant. DFT calculations provided a rationale for the specific efficiency of the diorganomagnesium-type two-electron reducing agent. The calculations show that the dianionic anthracene-9,10-diyl ligand reduces the two aryl ether substrates, resulting in the homocoupling reaction through supply of electrons to the Ni-Mg bimetallic system to form organomagnesium nickel(0)-ate complexes, which cause two sequential C–O bond cleavage reactions. The calculations also showed cooperative actions of Lewis acidic magnesium atoms and electron-rich nickel atoms in the C–O cleavage reactions. - An Introductory Overview of C–H Bond Activation/ Functionalization Chemistry with Focus on Catalytic C(sp3)–H Bond Borylation
Ronald Reyes, Masaya Sawamura
KIMIKA, 32, 1, 70, 109, Philippine Federation of Chemistry Societies, Inc., 13 May 2021, [Peer-reviewed], [Invited], [Last author, Corresponding author]
Scientific journal, The direct and selective functionalization of C–H bonds provides novel disconnections and innovative strategies to streamline the synthesis of molecules with diverse complexities. However, despite the significant advances in the elaboration of techniques for C–H activation, the utilization of unactivated C(sp3)–H bonds remains challenging. In particular, asymmetric transformation of C(sp3)–H bonds is underdeveloped owing to the lack of catalytic systems that can competently discriminate among ubiquitous C–H bonds in organic molecules. This short review aims to outline the challenges and strategies for the catalytic functionalization of C(sp3)–H bonds giving a general and non-exhaustive explanatory approach. Current strategies on the basis of the substrates and reaction mechanisms are summarized in Section 1. Examples of enantioselective C–H bond transformations are then given in Section 2. Finally, in Section 3, an outline of current methodologies towards the direct borylation of C(sp3)–H bonds is described to showcase the importance of developing techniques for catalytic C–H bond chemistry. While we try to cover all excellent reports available in the literature on this topic, any omissions are unintentional, taking note of the most representative examples available. - Use of Imidazo[1,5‐ a ]pyridin‐3‐ylidene as a Platform for Metal‐Imidazole Cooperative Catalysis: Silver‐Catalyzed Cyclization of Alkyne‐Tethered Carboxylic Acids
Vishal Kumar Rawat, Kosuke Higashida, Masaya Sawamura
Advanced Synthesis & Catalysis, 363, 6, 1631, 1637, Wiley, 16 Mar. 2021, [Peer-reviewed], [Last author, Corresponding author]
Scientific journal - Phosphinylation of Non‐activated Aryl Fluorides through Nucleophilic Aromatic Substitution at the Boundary of Concerted and Stepwise Mechanisms
Zhensheng You, Kosuke Higashida, Tomohiro Iwai, Masaya Sawamura
Angewandte Chemie International Edition, 60, 11, 5778, 5782, Wiley, 08 Mar. 2021, [Peer-reviewed], [Last author, Corresponding author]
Scientific journal - Synthesis of 4‐Hydroxy‐2‐pyridinone Derivatives and Evaluation of Their Antioxidant/Anticancer Activities
Wafaa S. Hamama, Eslam A. Ghaith, Mona E. Ibrahim, Masaya Sawamura, Hanafi H. Zoorob
ChemistrySelect, 6, 7, 1430, 1439, Wiley, 17 Feb. 2021, [Peer-reviewed]
Scientific journal - Dumbbell‐Shaped 2,2’‐Bipyridines: Controlled Metal Monochelation and Application to Ni‐Catalyzed Cross‐Couplings
Yongjoon Kim, Tomohiro Iwai, Sho Fujii, Kosei Ueno, Masaya Sawamura
Chemistry – A European Journal, 27, 7, 2289, 2293, Wiley, Feb. 2021, [Peer-reviewed], [Last author, Corresponding author]
English, Scientific journal, Dumbbell-shaped bipyridines, featuring distal steric effects of bipyridine C5- and C5'-triarylmethyl substituents, allowed controlled monochelation to transition metals. These newly synthesized ligands showed improved ligand performance compared to conventional bipyridine ligands in the Ni-catalyzed cross-electrophile coupling and the Ni/photoredox-synergistically catalyzed decarboxylative coupling. More information can be found in the Communication by T. Iwai, M. Sawamura, et al. (DOI: 10.1002/chem.202004053). - Copper-Catalyzed Reactions of Alkylboranes
Hirohisa Ohmiya, Masaya Sawamura
Bulletin of the Chemical Society of Japan, 94, 1, 197, 203, The Chemical Society of Japan, 15 Jan. 2021, [Peer-reviewed], [Invited], [Last author, Corresponding author]
Scientific journal - Asymmetric Remote C-H Borylation of Aliphatic Amides and Esters with a Modular Iridium Catalyst
Reyes, Ronald L., Sato, Miyu, Iwai, Tomohiro, Suzuki, Kimichi, Maeda, Satoshi, Sawamura, Masaya
Synthesis, 2021
Scientific journal - Convenient Synthesis of Binary and Fused Pyrazole Ring Systems: Accredited by Molecular Modeling and Biological Evaluation
Eslam A. Ghaith, Hanafi H. Zoorob, Mona E. Ibrahim, Masaya Sawamura, Wafaa S. Hamama
ChemistrySelect, 5, 47, 14917, 14923, Wiley, 18 Dec. 2020, [Peer-reviewed]
Scientific journal - The Scope of 3-acetyl-4-hydroxy-6-methyl-2H-pyran-2-one (DHA)
Eslam A. Ghaith, Hanafi H. Zoorob, Mona E. Ibrahim, Masaya Sawamura, Wafaa S. Hamama
Current Organic Chemistry, 24, 13, 1459, 1490, Bentham Science Publishers Ltd., 01 Oct. 2020, [Peer-reviewed]
Scientific journal,
The following review article provides an overview of DHA chemistry, with specific
confirmation based on major historical developments and progress mainly made over
the last two decenniums. It is our hope this review serves as a valuable treasure to those
interested in the 3-acetyl-4-hydroxy-6-methyl-2H-pyran-2-one (DHA) chemistry, and helps
impact future advancements. - Front Cover Picture: Iridium‐Catalyzed Enantioselective Transfer Hydrogenation of Ketones Controlled by Alcohol Hydrogen‐Bonding and sp3‐C−H Noncovalent Interactions (Adv. Synth. Catal. 21/2020)
Hiroaki Murayama, Yoshito Heike, Kosuke Higashida, Yohei Shimizu, Nuttapon Yodsin, Yutthana Wongnongwa, Siriporn Jungsuttiwong, Seiji Mori, Masaya Sawamura
Advanced Synthesis & Catalysis, 362, 21, 4445, 4445, Wiley, 15 Sep. 2020
Scientific journal - Polystyrene-Cross-Linking Triphenylphosphine on a Porous Monolith: Enhanced Catalytic Activity for Aryl Chloride Cross-Coupling in Biphasic Flow
Hikaru Matsumoto, Yu Hoshino, Tomohiro Iwai, Masaya Sawamura, Yoshiko Miura
Industrial & Engineering Chemistry Research, 59, 34, 15179, 15187, American Chemical Society (ACS), 26 Aug. 2020, [Peer-reviewed], [Corresponding author]
English, Scientific journal, Immobilized transition metals for continuous-flow catalyses are greatly in demand to achieve automation, scale-up, facile separation, regeneration, and energy-saving production with high level of sustainability and efficiency. Here, we report a tertiary phosphine immobilized on a macroporous monolith (M-PS-TPP) for the challenging Pd-catalyzed cross-coupling reaction of aryl chloride in a continuous-flow system. The monolithic and macroporous structure of M-PS-TPP was fabricated by bulk polymerization in the presence of a high internal phase emulsion (HIPE) template. Owing to the large pore size and high porosity, the M-PS-TPP showed high permeability against continuous flow of the mobile phase. The continuous-flow Suzuki-Miyaura cross-coupling reaction was realized by permeation of organic/aqueous media containing inorganic salt through a Pd-loaded monolith (M-PS-TPP-Pd) column without serious clogging. Controlling coordination chemistry and hydrodynamics of M-PS-TPP-Pd boosted highly active phosphine-metal complex formation and fast mass transfer of reactants. Indeed, the M-PS-TPP-Pd column showed surprisingly higher yields (similar to 93%) and turnover numbers (2704) under continuous-flow conditions than that under batch conditions (similar to 6%). - Polystyrene‐Supported PPh3 in Monolithic Porous Material: Effect of Cross‐Linking Degree on Coordination Mode and Catalytic Activity in Pd‐Catalyzed C−C Cross‐Coupling of Aryl Chlorides
Hikaru Matsumoto, Yu Hoshino, Tomohiro Iwai, Masaya Sawamura, Yoshiko Miura
ChemCatChem, 12, 16, 4034, 4037, Wiley, 20 Aug. 2020, [Peer-reviewed], [Corresponding author]
English, Scientific journal, Hybridization of porous synthetic polymer and sophisticated ligands play an important role in transition-metal catalysis for chemical transformations at laboratory and industrial levels. A monolithic porous polymer, which is a single piece with continuous macropores, is desired for high permeability, fast mass transfer properties, high stability, and easy modification. Herein, we first develop a monolithic porous polystyrene containing three-fold cross-linked PPh3(M-PS-TPP) for transition-metal catalysis. The monolithic and macroporous structure ofM-PS-TPPwas fabricated via polymerization-induced phase separation using porogenic solvent. Moreover, theM-PS-TPPwas synthesized using different feed ratios of divinylbenzene (DVB) for site-isolation and mono-P-ligating behavior of PPh3.P-31 CP/MAS NMR analysis revealed that the different selectivity ofM-PS-TPPs was obtained in formation of mono-P-ligation toward Pd-II. The macroporous properties and controlled mono-P-ligating behavior ofM-PS-TPPfacilitated the challenging Pd-catalyzed Suzuki-Miyaura cross-coupling reaction of chloroarenes. - Iridium‐Catalyzed Enantioselective Transfer Hydrogenation of Ketones Controlled by Alcohol Hydrogen‐Bonding and sp 3 ‐C−H Noncovalent Interactions
Hiroaki Murayama, Yoshito Heike, Kosuke Higashida, Yohei Shimizu, Nuttapon Yodsin, Yutthana Wongnongwa, Siriporn Jungsuttiwong, Seiji Mori, Masaya Sawamura
Advanced Synthesis & Catalysis, 362, 21, 4655, 4661, Wiley, 09 Jul. 2020, [Peer-reviewed], [Corresponding author]
Scientific journal - Ir-Catalyzed Reversible Acceptorless Dehydrogenation/Hydrogenation of N-Substituted and Unsubstituted Heterocycles Enabled by a Polymer-Cross-Linking Bisphosphine
Deliang Zhang, Tomohiro Iwai, Masaya Sawamura
Organic Letters, 22, 13, 5240, 5245, American Chemical Society (ACS), 02 Jul. 2020, [Peer-reviewed], [Corresponding author]
English, Scientific journal, The polystyrene-cross-linking bisphosphine ligand PS-DPPBz was effective for the Ir-catalyzed reversible acceptorless dehydrogenation/hydrogenation of N-heterocycles. Notably, this protocol is applicable to the dehydrogenation of N-substituted indoline derivatives with various N-substituents with different electronic and steric natures. A reaction pathway involving oxidative addition of an N-adjacent C(sp(3))-H bond to a bisphosphine-coordinated Ir(I) center is proposed for the dehydrogenation of N-substituted substrates. - Dinaphtho[2,1-d:1',2'-f][1,3,2]dioxaphosphepin, 4-_2から調製される表面固定化Ir錯体が嵩高い多置換アルケンの水素化に非常に高い活性を示すことを見いだした。さらに[Silica]-SMAPと[RhCl(ethylene)_2]]_2から調製される固定化Rh錯体を用いることにより、多置換ベンゼンの水素化にも成功した。
2.アルカンチオール化SMAPの金表面高密度自己組織化と触媒反応への応用に関する研究
まずアルカンチオール化SMAPを合成し、これを用いて金表面上に自己組織化単分子膜を形成させた。表面構造の解析は、XPS,ICP-MS, AFM, CVなどにより行い、表面上でホスフィンがほぼ最密充填していることを明らかにした。そのRh錯体はアルコールの脱水素化に対して高い触媒活性と優れた再利用効率を示した。幅広い一級アルコールに対して室温で高い活性を示す一方、2級アルコールにはまったく活性を示さない点も本触媒系の大きな特徴である。
日本学術振興会, 特定領域研究, 北海道大学, 19028003 - Catalyst Design Based on Functionalized Phosphines with a Compact Coordination Center
Grants-in-Aid for Scientific Research
2006 - 2007
SAWAMURA Masaya
1. Research with Caged Phosphine SMAP
The procedure for the synthesis of Ph-SMAP, the parent compound for various SMAP derivatives, was improved. It was confirmed that Ph-SMAP is an excellent ligand for hydrosilylation and hydrgenation of ketones.
SMAP was immobilized on silica gel surface. Silica-SMAP thus obtained showed very high ligand performance for the Rh-catalyzed hydrosilylation and hydrogenation of sterically demanding ketones.Furthermore, Silica-SMAP was successfully used for the development of Ir-catalyzed directed ortho borylation of functionalized arenes.
SMAP derivatives bearing an alkanethiol pendant at the bridgehead silicon atom was prepared and used for the preparation of self-assembled monolayer on gold surface. Au-SMAP thus prepared showed remarkably high activity and turnover efficiency in the Rh-catalyzed dehydrogenative alcohol silylation.
2. Research with Semihollow Trialkynylphosphines
Triethynylphosphine ligands with different end-cap groups were synthesized. Those with bulky end-caps showed unique coordination properties to form 1:1 metal-phosphine complexes selectively with various transition metal species. The semihollow-shaped triethynylphosphines showed extraordinally high accelerating effect in the Rh-catalyzed hydrosilylation of ketones. Furthermore, the semihollow triethynylphosphines were successfully used as ligands for gold-catalyzed alkyne cyclizations. In particular, the accelerating effect in the 6-exo-dig and 7-exo-dig cyclization was remarkable. In addition, this catalyst system enabled unprecedented cyclizations of internal alkyne derivatives.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido Univesity, 18350047 - 11族元素錯体触媒による新反応と不斉反応の開発
科学研究費助成事業
2006 - 2006
澤村 正也
我々がすでに開発しているCu(I)-Xantphos触媒によるアリルホウ素生成反応は、アリルアルコール誘導体を位置および立体選択的にアリルホウ素化合物に直接変換できる唯一の反応である。
光学活性配位子を適用してこの反応を不斉触媒化することを検討し、Z配置のアリル炭酸エステルの反応に、不斉配位子として1,2-ビス(ホスフィノ)アレーン骨格を有し、リン原子がジアルキル-モノアリールホスフィン型のものを適用することにより高いエナンチオ選択性が発現することを見出した。不斉配位子としてQuinoxP^*を用いることにより、96%eeという実用的レベルの高選択性を達成できた。
シクロプロパン骨格は天然有機化合物にしばしば見られる構造であるとともに、液晶のコアとしても利用されている。ボリルシクロプロパンはこれらシクロプロパン骨格を持つ化合物を合成するためのビルディングブロックとして有用である。シクロプロパン化合物の多くは環内に不斉点を有するため、光学活性ボリルシクロプロパンは特に重要である。
既存の光学活性ボリルシクロプロパン合成法のほとんどは不斉補助基を量論的に用いるものであり、触媒的不斉合成は、置換シクロプロペンの不斉ヒドロホウ素化によるものが唯一の例である。
Xantphos-銅(I)触媒によるアリルホウ素の合成法を研究する中で、脱離基γ位の置換基がシリル基の場合、Cu-Bのアルケンへの付加の位置選択性が逆転し、その結果としてtrans-1-シリル-2-ボリルシクロプロパンが生成することを見出した。アリル炭酸エステルのアルケン部位の立体配置が、反応性、付加の位置選択性、立体選択性のいずれにも大きな影響を及ぼし、いずれもZ体の方が優れている。ホスフィン配位子としてXantphosの代わりにSEGPHOSやQuinoxP^*を用いると、反応速度が少し低下したが、高い光学純度のtrans-1-シリル-2-ボリルシクロプロパンが高収率で得られた。
シクロプロパン上のシリル基とボリル基は、それぞれ段階的に立体選択的に変換可能である。これを利用する収束的な合成法は、光学活性シクロプロパン化合物の優れた合成手法になるものと期待できる。
日本学術振興会, 特定領域研究, 北海道大学, 18037001 - 遷移金属錯体触媒の精密組織化と応用
ＪＳＴ戦略的創造研究推進制度（個人研究型） （個人研究推進事業：さきがけ研究２１‐ＰＲＥＳＴＯ）
2002 - 2005
Competitive research funding - Atomic Level Organization of Transition Metal Complexes for Use in Organic Synthesis
JST Basic Research Programs (Precursory Research for Embryonic Science and Technology :PRESTO)
2002 - 2005
Competitive research funding - 炭素クラスター複合体の精密有機合成化学
科学研究費助成事業
2001 - 2004
中村 栄一, 松尾 豊, 赤阪 健, 澤村 正也
2002年よりフラーレン,ナノチューブの大量合成が企業化され,ナノテクノロジーの中核技術としてますます注目されている.フラーレンやカーボンナノチューブなどの炭素クラスターそのものの性質は相当程度解明されたといえるが,それらの材料としてのポテンシャルを高めるためには,「化学修飾炭素クラスターの精密合成化学」の研究を展開することが必須である.本研究の目的は,炭素クラスター同士の複合体,炭素クラスターと有機分子,金属,生体分子などとの複合体を,炭素共有結合形成を鍵にして高効率・高選択的に作り出すことである.その結果,次世代の材料科学,ナノテクノロジーや医学に資する新しい物質科学を創成できると同時に,精密合成化学,触媒化学など基礎化学分野での新発見が期待できる.
本年度は,機能性炭素クラスター分子合成の取りまとめとして,五重付加型フラーレン誘導体およびアミノ化フラーレン誘導体の工業製品レベルの大量供給の方法を確立した.また,フラーレン誘導体からさらに修飾して得られるフラーレン-遷移金属錯体についてもいくつか代表的なものについては簡便に大量合成を行う方法を開発した.さらに,官能基化されたフラーレン遷移金属錯体や多核のフラーレン-遷移金属錯体を合成する手法も確立し,今後,電子デバイスへの実用化に向けた研究を展開することが可能となった.新しい分子集合の様式で液晶性を示す炭素クラスター複合体液晶分子(シャトルコック液晶分子)についても,より液晶相を発現させやすく,種々の誘導化が簡便な第二世代のシャトルコック分子を大量合成を可能にする研究を行った。また,金属内包フラーレンイオン種の種々の反応(ケイ素化反応,カルベンとの反応,ジアゾ化合物との反応など)について研究を行い,得られる化合物の反応性と物性を調査した.
日本学術振興会, 特別推進研究, 東京大学, 13001002 - Synthetic Chemistry and Materials Chemistry of Functionalized Fullerenes
Grants-in-Aid for Scientific Research
2001 - 2002
MASAYA Sawamura
During our studies on fullerene functionalization, we have found a one-step five-fold addition of a phenylcopper(I) reagent to [60]fullerene. This reaction produces a.cyclopenadiene embedded in a spherical surface of [60]fullerene. The cyclopentadiene in the new molecule consists of one of the twelve pentagon of [60]fullerene, and is surrounded by the five sp3 carbon atoms bearing a phenyl substituent derived from the organocopper reagent. The cyclopentadiene structure can be converted into 6-π electron cyclopentadienyl anion through deprotonation by a base. Metal complexes containing a five-carbon ligand cyclopentadienyl (Cp) play very important roles in organometallic chemistry. This study aimed at synthesis of functional molecules useful for applications as catalysts and materials by means of such functionalized fullerenes.
As results of this study, the multiple addition of organocopper reagents to fullerenes have been significantly improved so that various fullerene derivatives with different organic substituents can be synthesized in quantitative yields in large scales. Hybrids of fullerenes (C60 and C70) and ferrocene were synthesized. It was found that alkali metal salts of the cyclopentadienyl type-fullerenes are soluble in water and that they forms spherical bilayer vesicles. Derivatives with liquid crystalline properties and double decker Cp-type compounds were also synthesized.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 13440187 - 最小最強ホスフィン配位子―ケイ素含有カゴ型ホスフィンの設計と合成
科学研究費助成事業
2001 - 2001
澤村 正也
本研究課題では,これまでに知られるどのホスフィン配位子よりも立体障害が小さく,電子供与性が強い「世界最小・最強ホスフィン配位子」としてケイ素含有カゴ型ホスフィンを設計し,その合成経路に関する検討を徹底的に行った.この配位子はケイ素原子とリン原子の間に効果的な軌道相互作用があり,これによりリン原子の電子供与性が著しく増大することが非経験的分子軌道計算(プロトン化による安定化の比較,HF/3-21G^<(*)>)による検討からすでに明らかになっている.その合成戦略として,ケイ素原子上での環形成により合成を完了する経路とリン原子上での環形成をもって達成する経路を検討した.
前者の経路はまず,トリビニルホスフィンに対するシランの連続ヒドロシリル化により一気にビシクロ骨格を構築することを計画して行った.しかしながら,分子間でのヒドロシリル化や自己重合を抑えられず合成経路としては不向きであることが判明した.また,トリス2-メタロエチルホスフィン-ボラン錯体を合成中間体としてケイ素原子上での環形成を種々試みたが,錯体の安定性等に問題があった.
もう一方の経路であるリン原子上での環形成を伴う手法では,トリビニルホスフィンを出発原料とした.トリス(2-ブロモエチル)シランを合成し,これをリチウム-ハロゲン交換によりリチオ化した後に,塩化リンを加えたところ,ESI-マススペクトルにより目的のカゴ型ホスフィンの生成を示唆するピークが得られた.
日本学術振興会, 萌芽的研究, 北海道大学, 13874095 - 単一金属系新反応
科学研究費助成事業
1997 - 1999
村井 真二, 真島 和志, 直田 健, 澤村 正也, 溝部 裕司, 水野 一彦, 光藤 武明, 村上 正浩, 岩澤 康裕
当初から述べているように、本研究では単一金属系新反応の分野における新概念の開拓と蓄積をはかり、合成化学的応用に結びつけることを目的としている。これらの単一金属としては遷移金属元素や前周期遷移金属元素を主にとりあげ、典型金属元素もとりあげている。
本年度も引き続き、炭素共有結合形成のための新手法の開発を行った。そのため、遷移金属元素を中心として、これらと種々の型式の有機化合物ないし、有機化合物中の官能基との相互作用を極めて広範囲に調査し、これらを通じて得られる異常現象、非古典的現象の芽を蓄積し、専門の異なる研究者がチームをつくりつつ、これらの新現象の普遍化への方策を開拓した。
研究成果の一例として、前年度に導入した高性能な核磁気共鳴吸収装置は、引き続き順調に稼働しており、C-H/オレフィンカップリング反応機構をさらに深く追及していくことができた(村井)。14族有機金属化合物の光誘起電子移動反応の新たな解明にむけての成果が得られた(水野)。また、炭素間単結合間に分子内のオレフィンが挿入するという新触媒反応を見い出した(村上)。
さらに、本年度導入した反応解析モニタリングシステム(React IR 1000)は順調に稼働しており、反応の機構や経路についての重要なデータを鋭意蓄積しつつある(澤村)。
全体として、本年度は計画通り順調に研究が進展したといえる。
日本学術振興会, 特定領域研究(A), 大阪大学, 09238103 - 新有機反応メディア
科学研究費助成事業
1997 - 1999
吉田 潤一, 碇屋 隆雄, 大嶋 幸一郎, 神戸 宣明, 谷野 圭持, 岩澤 伸治, 澤村 正也, 堀口 良昭
本研究では新化学現象・新反応の発見と開拓のために、反応の分子環境としての反応場、反応剤、反応媒体、反応手法などを反応メディアという観点から研究を行ってきた。とくに、電子移動反応場、高分子反応場、結晶反応場、ラジカル反応場、金属錯体反応場、特異条件反応場とそれらの境界領域について重点的に検討を行い、新現象・新反応の発見を目指して検討を行ってきた。その結果、多くの特筆すべき成果を得ることができた。以下に示す。
電子移動反応場においては、活性種の生成条件を高度に制御することにより、生成した活性種を蓄え、それを結合生成反応に用いるというカチオンプール法を開拓し、炭素-炭素結合生成反応の新しい方法論を明らかにした。さらに、電解反応場と固体マトリックス反応場の組み合わせにより、高効率・高選択的な分子変換法を明らかにした。また、有機金属反応場、ラジカル反応場、カチオン反応場においては、新活性種や機能性反応場反応の構築などにおいて顕著な成果を上げることができた。
媒体の研究においても注目すべき成果が得られた。すなわち、水中におけるラジカル反応において、従来の有機溶媒中の反応にみられない興味深い応性の変化や選択性の変化が観測されることを明らかにした。また、水中におけるイオン反応の促進効果を利用し、ラジカル反応とイオン反応を組み合わせる新しい反応系の開発をも明らかにした。さらに、超臨界流体における金属触媒反応においては、流体の特性を活かすことにより触媒の活性を大きく向上できることを明らかにした。
日本学術振興会, 特定領域研究(A), 京都大学, 09238102 - ポルフィリン-遷移金属ホスフィン錯体集積反応場による光エネルギーの利用
科学研究費助成事業
1998 - 1998
澤村 正也
ポルフィリンの光機能物質としての性質と遷移金属ホスフィン錯体の多彩な触媒活性を組み合わせることにより,光エネルギーを有効利用できる触媒的物質変換システムを創出することを目的として,ポルフィリン部位を有するビスホスフィン錯体およびその遷移金属錯体を合成した.自然光を利用するアルカンの脱水素反応(不活性C-H結合活性化)を実現することが究極の目標である.
(1) 配位子の合成 目的化合物のホスフィン部位は酸化反応に対して不安定と予想されたので,あらかじめホスフィンスルフィドとして保護してからポルフィリン環に組み込み,最終段階で脱保護をする戦略をとった.その結果,リン原子の位置が異なる2種類の配位子を合成することに成功した.
(2) 遷移金属錯体の合成と物性 触媒反応の検討に先立ち,いくつかの基本的な遷移金属ホスフィン錯体を合成し,その構造および性質を調べた.吸収スペクトルおよび蛍光スペクトルを測定した.
(3) 触媒反応 今回合成された錯体の内,パラジウム錯体は有機ホウ素化合物と有機ハロゲン化物のクロッスカップリングに,ロジウム錯体は活性化ニトリルのマイケル付加に活性を示した.
日本学術振興会, 萌芽的研究, 東京大学, 10874086 - Synthesis of Functional Organometallic Complexes Involving a Pentahaptofullerene Ligand
Grants-in-Aid for Scientific Research
1997 - 1998
SAWAMURA Masaya
The pentaphenylated fullerene anion C_<60>Ph_5-, which is obtained through the five-fold addition of an organocopper reagent to C_<60>, and its metal complexes represent a new class of cyclopentadiene derivatives, which can be prepared through deprotonation of the parent compond. One out of twelve pentagons in C_<60> is isolated from the remaining 50 sp^2 carbon atoms of the C_<60> molecule by five surrounding sp3 carbon atoms each bearing a phenyl group. The previous X-ray crystallographic studies revealed the highly unique cavity structure formed around the cyclopentadienyl (Cp) moiety by the five phenyl groups, but failed to give us information on the electronic properties of these unique molecules. In this research project, we have carried out ab-initio molecular orbital calculations and electrochemical experiments and obtained evidence that there is endohedral homoconjugation, that is, an electronic interaction between the upper Cp and the lower C_<50> moiety in C_<60>Ph_5-and C_<60>Ph_5H through inside of the C_<60> cage.
We also found that the reaction of C_<70> with an organ ocopper reagent gives a trisaddition product [C_<7O>Ar_3H, Ar = 4-CF_3-C_6H_4] with an indene-like substructure flanked by the three sp^3 carbons in a quantitative yield. The trisadduct was deprotonated with metal alkoxides to form the corresponding metal complexes C_<70>Ar_3M [M=K, Tl]. The results of ab initio molecular orbital calculations and X-ray diffraction study suggested that C_<70>Ar_3- coordinates to the metal as an eta^5-indenylide rather than a eta^3-ligand in C_<7O>Ar_3M.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), The University of Tokyo, 09440238 - 機能性有機金属錯体触媒の創出を指向するC_<5v>対称η^5-フラーレン配位子の開発
科学研究費助成事業
1996 - 1996
澤村 正也
金属錯体触媒の分野は今,高活性,高選択性を追求する研究から,機能性触媒の開発へと研究のフロンティアが変わろうとしている.これに応じて,新概念に基づいた触媒設計の必要性が生まれてくる.申請者は,フラーレンの特異な電子構造,適度な大きさ,および三次元的な空間の広がりが機能性配位子を設計する上での基盤として適していると考え,これを目指したフラーレンの化学修飾の研究に着手した.そして様々な検討の結果,有機銅試薬のC_<60>への付加反応において,五つのフェニル基が一つの五員環の廻りを取り囲むように位置選択的に連続付加し,C_S対称のシクロペンタジエン型置換体C_<60>Ph_5Hが定量的な収率で得られることを発見,さらに,LiOtBu,KOtBu,TlOEt及びCuOtBu(PEt_3)によって脱プロトン化することにより対応するシクロペンタジエニル型η_5-フラーレン金属錯体を合成した.中でもタリウム錯体についてはX線結晶構造解析にも成功し,C_5対称の構造を確認した(文献1).
フラーレンがその球状表面の5角形の部分でη^5-配位する他に類を見ない特異な構造を有するこれらの金属錯体は,予想される主な特徴として,「幅広い金属に対する強い配位力」,「フラーレン部位の可逆的電子受容能および光励起能」,「50π系ポリオレフィン部位とCp部位との間のフラーレンケージ内部空間を通した電子的相互作用」,および「Cp部位を取り囲む5つの置換基により,Cp環を底とする深いすり鉢状の空間が形成される点」などが挙げられ,機能性配位子として要求される性質を備えている.
日本学術振興会, 萌芽的研究, 東京大学, 08874093 - 炭素共有結合形成手法の新機軸
科学研究費助成事業
1996 - 1996
村井 真二, 沢村 正也, 藤原 祐三, 中村 栄一, 吉田 潤一, 安田 源
本研究は平成9年度新規設定領域として発足予定の重点領域「有機化学新現象-多元素協同作用に基づく炭素共有結合形成の新機軸-」、領域略称「炭素結合形成」、領域番号283、領域代表者大阪大学工学部教授村井真二、研究期間平成9年度-11年度、についてそのスムーズな開始と進展をはかるための企画、調査、調整を行った。
本重点領域研究「炭素結合形成」は、有機化学の新しい現象を発見・開拓し、これらの展開研究を行うことにより、新しい有機合成手法の開拓、新しい有機化学概念の確立、新しい有機化学理論の構築を目指すものである。この重点領域研究の目標達成への準備として、効果的な研究組織、その運営方法、公募研究と計画研究との調整企画、研究評価法の策定などを行った。公募研究の公募については広報活動に努め、ポスターやインターネットホームページ設定等の手段を用いた結果、期待どうり多数の公募研究課題の応募があった。
日本学術振興会, 基盤研究(B), 大阪大学, 08355029 - トランスキレート光学活性ホスフィンを用いる触媒的不斉合成
科学研究費助成事業
1996 - 1996
澤村 正也
申請者らはこれまでに各種遷移金属に対しトランスの位置にまがたってキレート配位する光学活性2座ホスフィン配位子2,2“-bis[1-(diarylphosphino)enthyl]-1,1"-biferrocene(arylTRAP)および2,2“-bis[1-(dialkylphosphino)enthyl]-1,1"-biferrocene(alkyTRAP)を種々合成し,その触媒的不斉合成への応用を行ってきた.
これまでもっぱらロジウム触媒による反応において成果を上げていたが,本年度は新たにパラジウム触媒による反応の開発を手掛けた.さまざまな検討を行った結果,1,6-エン-イン化合物の不斉環化反応(文献1)やRh-Pdバイメタリック触媒形によるα-シアノエステルのアリル化反応などの新規不斉触媒反応(文献2)を開発することができた.
また芳香族有機金属試薬とハロゲン化アリールのPd触媒不斉クロスカップリング反応(鈴木カップリング)による軸不斉ビアリール化合物の合成についても検討した.不斉反応という観点からはまだ大きな成果は得られていないが,TRAP配位子が本反応において顕著な加速効果を示すという大変興味深い結果を得た.TRAP配位子がパラジウムにトランスキレートの様式で配位することを考慮に入れると,この事実は反応機構的にも興味深い.今後はさまざまな基質の反応にTRAP配位子を適用し,この加速効果の一般性,有用性を検証しながら鋭意検討を加えることにより,本反応が高次構造有機化合物の合成に役立つ,実践的分子変換法となるよう努力する.
日本学術振興会, 重点領域研究, 東京大学, 08245212 - 新規トランスキレート光学活性ホスフィン配位子の開発
科学研究費助成事業
1995 - 1995
澤村 正也
申請者らはこれまでに各種遷移金属に対しトランスの位置にまたがってキレート配位する光学活性2座ホスフィン配位子2,2"-bis[l-(diarylphosphino)ethyl]-l,l"-biferrocene(arylTRAP)および2,2"-bis[l-(dialkylphosphino)ethyl]-l,l"-biferrocene(alkylTRAP)を種々合成し,これらのロジウム錯体が活性化ニトリルの不斉マイケル付加反応,ケトンの不斉ヒドロシリル化反応,オレフィンの不斉水素化反応などにおいて非常に効率的な触媒となることを報告している.
本研究では新しい光学活性トランスキレート配位子としてTRAPの2つのフェロセンの間にケイ素原子が挿入した配位子STRAP及び,光学活性meridional3座配位子となることが予想される配位子としフェロセン間にリン原子が挿入したものの合成を試みた.
まずSTRAPと3座ホスフィン配位子の両方の合成中間体となる(R)-(S)-{2-(l-diphenylphos-phino)ethyl-l-tributylstanylferrocene}を(R)-[l-(N,N-dimethylamino)ethylferrocene]から1)ジアステレオ選択的オルトリチオ化,2)スタニル化,及び3)ジフェニルホスフィンによる置換反応を経て合成した.続いてブチルリチウムによるトランスメタル化とジクロロジメチルシランによる補足によりSTRAPを一気に合成することを種々の条件で試みたが未だ成功には至っていない.ジクロロフェニルホスフィンによる補足にも成功していない.このような経過を踏まえ,現在は,先にケイ素原子やリン原子でフェロセンを繋いだ後に,ジメチルアミノ基をジフェニルホスフィノ基などで置換する合成経路を検討中である.
日本学術振興会, 一般研究(C), 東京大学, 07651054 - 機能性有機金属化合物の開発
Competitive research funding - Development of Functional Organometallic Compounds
Competitive research funding
Educational Organization
- Bachelor's degree program, School of Science
- Master's degree program, Graduate School of Chemical Sciences and Engineering
- Doctoral (PhD) degree program, Graduate School of Chemical Sciences and Engineering
