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A04 小島 隆彦

 小島 隆彦

公募班 A04

所 属

筑波大学 数理物質系

役 職

教授

連絡先

kojima@chem.tsukuba.ac.jp

研究室HP

http://www.chem.tsukuba.ac.jp/kojima/Site/Site/Home.htm

研究課題

らせん不斉を有する錯体触媒の開発と不斉酸化反応への応用

研究組織

研究協力者:石塚 智也(筑波大学数理物質系・講師)

研究協力者:小谷 弘明(筑波大学数理物質系・助教)

研究内容

これまでの金属錯体触媒による不斉酸化反応では、その配位子に不斉炭素や軸不斉を導入した触媒が用いられてきた。本研究の目的は、金属錯体触媒の金属周りのらせん不斉(ΔΛ)に基づく、全く新しい不斉酸化反応系の開発である。その方策として、不斉点を持たないピリジルアミン系多座配位子がらせん不斉構造を安定に保持し、かつ高活性な酸化活性高原子価オキソ錯体を形成しうるルテニウム錯体を用いる。この配位子に、オキソ配位子の近傍に立体的な不斉反応場を構築するため、立体的にかさ高い置換基を導入し、「メタロヘリセン」構造を構築する。その前駆体錯体の酸化により、らせん不斉を有するRu(IV)-オキソ錯体を生成させ、ラセミ混合物のアルコール類の速度論的光学分割、C-H結合の不斉水酸化、オレフィン類の不斉エポキシ化などを試みる。さらに、量論的酸化反応の速度論的解析及びDFT計算に基づいて、その反応機構を明らかにするとともに、不斉選択性の要因を明らかにする。

専門分野

錯体化学、触媒化学、ポルフィリン化学、酸化還元化学

研究キーワード

らせん不斉、ルテニウム錯体、不斉酸化反応

研究業績

2021

[31] Long-Range Order in Supramolecular π Assemblies in Discrete Multi-Decker Naphthalenediimides,
Sudhir Kumar Keshri; Tomoya Ishizuka; Takahiko Kojima; Yoshitake Matsushita; Masayuki Takeuchi, J. Am. Chem. Soc., 143, 8, 3238 – 3244, 2021
DOI: 10.1021/jacs.0c13389.

2020

[30] Iron Complex of a Quadruply Fused Porphyrin: Synthesis, Structure and Redox Properties,
Tomoya Ishizuka; Keiyu Komamura; Yuta Saegusa; Shogo Tanaka; Yoshihito Shiota; Kazunari Yoshizawa; Takahiko Kojima, Journal of Porphyrins and Phthalocyanines, 24, 1-3, 252 – 258, 2020
DOI: 10.1142/S1088424619500846.
[29] Photocatalytic Hydrogen Evolution Using a Ru(II)-Bound Heteroaromatic Ligand as a Reactive Site,
Takuya Sawaki; Tomoya Ishizuka; Nanase Namura; Dachao Hong; Mayuko Miyanishi; Yoshihito Shiota; Hiroaki Kotani; Kazunari Yoshizawa; Jieun Jung; Shunichi Fukuzumi; Takahiko Kojima, Dalton Trans., 49, 47, 17230 – 17242, 2020
DOI: 10.1039/D0DT03546G.
[28] Selective Convergence to Atropisomers of a Porphyrin Derivative Having Bulky Substituents at the Periphery,
Tomoya Ishizuka; ShogoTanaka; Sayaka Uchida; Lianyu Wei; Takahiko Kojima, J. Org. Chem., 85, 20, 12856 – 12869, 2020
DOI: 10.1021/acs.joc.0c01876.
[27] Mechanistic Insight into Concerted Proton-Electron Transfer of a Ru(IV)-Oxo Complex: A Possible Oxidative Asynchronicity,
Hiroaki Kotani; Hinatsu Shimomura; Kei Ikeda; Tomoya Ishizuka; Yoshihito Shiota; Kazunari Yoshizawa; Takahiko Kojima, J. Am. Chem. Soc., 142, 40, 16982 – 16989, 2020
DOI: 10.1021/jacs.0c05738.
[26] Study on Proton-Coupled Electron Transfer in Transition Metal Complexes,
Takahiko Kojima, Bull. Chem. Soc. Jpn., 93, 12, 1571 – 1582, 2020
DOI: 0.1246/bcsj.20200213.
[25] Redox Properties of a Bipyrimidine-Bridged Dinuclear Ruthenium(II) Complex,
Tomoya Ishizuka; Masaki Itogawa; Hinatsu Shimomura; Yoshihito Shiota; Hiroaki Kotani; Kazunari Yoshizawa; Takahiko Kojima, Inorg. Chem. Commun., 120, 108150 – 1081510, 2020
DOI: 10.1016/j.inoche.2020.108150.
[24] Selective catalytic 2e-oxidation of organic substrates by an FeII complex having an N-heterocyclic carbene ligand in water,
Hiroto Fujisaki; Tomoya Ishizuka; Yoshihiro Shimoyama; Hiroaki Kotani; Yoshihito Shiota; Kazunari Yoshizawa; Takahiko Kojima, Chem. Commun., 56, 68, 9783 – 9786, 2020
DOI: 10.1039/D0CC03289A.
[23] A Mechanistic Dichotomy in Two-Electron Reduction of Dioxygen Catalyzed by N,N’-Dimethylated Porphyrin Isomers,
Wataru Suzuki; Hiroaki Kotani; Tomoya Ishizuka; Takahiko Kojima, Chem. Eur. J., 26, 46, 10480 – 10486, 2020
DOI: 10.1002/chem.202000942.
[22] Conformational Dynamics of Monomeric- vs Dimeric-like Features in Naphthalenediimide-based Conjugated Cyclophane,
Sudhir Kumar Keshri; Atsuro Takai; Tomoya Ishizuka; Takahiko Kojima; Masayuki Takeuchi, Angew. Chem. Int. Ed., 59, 13, 5254 – 5258, 2020
DOI: 10.1002/anie.201914414.
[21] Efficient Near-Infrared Light-Driven Hydrogen Evolution Catalyzed by a Saddle-Distorted Porphyrin as a Photocatalyst,
Hiroaki Kotani; Takuya Miyazaki; Emi Aoki; Hayato Sakai; Taku Hasobe; Takahiko Kojima, ACS Applied Energy Materials, 3, 4, 3193 – 3197, 2020
DOI: org/10.1021/acsaem.0c00206.
[20] Development of functionality of metal complexes based on proton-coupled electron transfer,
Takahiko Kojima, Dalton Trans., 49, 22, 7284 – 7293, 2020
DOI: 10.1039/D0DT00898B.
[19] Cooperative Effects of Hetero-Dinuclear IrIII-MII Complexes on Catalytic H2Evolution from Formic Acid Dehydrogenation in Water,
Dachao Hong; Yoshihiro Shimoyama; Yuji Ohgomori; Ryoichi Kanega; Hiroaki Kotani; Tomoya Ishizuka; Yoshihiro Kon; Yuichiro Himeda; Takahiko Kojima, Inorg. Chem., 59, 17, 11976 – 11985, 2020
DOI: 10.1021/acs.inorgchem.0c00812.
[18] Discrete π–Stack of a Tweezer-Shaped Naphthalenediimide-Anthracene Conjugate,
Sudhir Kumar Keshri; Waka Nakanishi; Atsuro Takai; Tomoya Ishizuka; Takahiko Kojima; Masayuki Takeuchi, Chem. Eur. J., 26, 58, 13288 – 13294, 2020
DOI: 10.1002/chem.202002477.

2019

[17] A Diprotonated Porphyrin as an Electron Mediator in Photoinduced Electron Transfer in Hydrogen-Bonded Supramolecular Assemblies,
Wataru Suzuki; Hiroaki Kotani; Tomoya Ishizuka; Masaki Kawano; Hayato Sakai; Taku Hasobe; Kei Ohkubo; Shunichi Fukuzumi; Takahiko Kojima, J. Phys. Chem. C, 123, 18, 11529 – 11538, 2019
DOI: 10.1021/acs.jpcc.9b02449.
[16] Catalytic Oxidative Cracking of Benzene Rings in Water,
Yoshihiro Shimoyama; Tomoya Ishizuka; Hiroaki Kotani; Takahiko Kojima, ACS Catal., 9, 1, 671 – 679, 2019
DOI: 10.1021/acscatal.8b04004.
[15] Significant Enhancement of Hole Transport Ability in Conjugated Polymer/Fullerene Bulk Heterojunction Microspheres,
Amandeep Jindal; Hiroaki Kotani; Soh Kushida; Akinori Saeki; Takahiko Kojima; Yohei Yamamoto, ACS Applied Polymer Materials, 1, 2, 118 – 123, 2019
DOI: 10.1021/acsapm.8b00170.
[14] Identification of Intermediates in Peroxidase Catalytic Cycle of a DNAzyme Possessing Heme,
Ryosuke Shinomiya; Haruka Araki; Atsuya Momotake; Hiroaki Kotani; Takahiko Kojima; Yasuhiko Yamamoto, Bull. Chem. Soc. Jpn., 92, 10, 1729 – 1736, 2019
DOI: 10.1246/bcsj.20190157.
[13] Metal-Oxyl Species and Their Possible Roles in Chemical Oxidations,
Yoshihiro Shimoyama; Takahiko Kojima, Inorg. Chem., 58, 15, 9517 – 9542, 2019
DOI: 10.1021/acs.inorgchem.8b03459.
[12] Fundamental electron-transfer and proton-coupled electron-transfer properties of Ru(IV)-oxo complexes,
Hiroaki Kotani; Hinatsu Shimomura; Momoko Horimoto; Tomoya Ishizuka; Yoshihito Shiota; Kazunari Yoshizawa; Sachiko Yanagisawa; Yuka Kawahara-Nakagawa; Minoru Kubo; Takahiko Kojima, Dalton Trans., 48, 35, 13154 – 13161, 2019
DOI: 10.1039/C9DT02734C.
[11] Mechanistic Insight into Synergistic Catalysis of Olefin Hydrogenation by a Hetero-Dinuclear RuII-CoII Complex with Adjacent Reaction Sites,
Dachao Hong; Yuji Ohgomori; Yoshihiro Shimoyama; Hiroaki Kotani; Tomoya Ishizuka; Yoshihiro Kon; Takahiko Kojima, Inorg. Chem., 58, 17, 11284 – 11288, 2019
DOI: 10.1021/acs.inorgchem.9b02104.
[10] Excellent Oxygen Reduction Reaction Performance in Self-Assembled Amyloid-β/Platinum Nanoparticle Hybrids with Effective Platinum-Nitrogen Bond Formation,
Amandeep Jindal; Kentaro Tashiro; Hiroaki Kotani; Toshiaki Takei; Sven Reichenberger; Galina Marzun; Stephan Barcikowski; Takahiko Kojima; Yohei Yamamoto, ACS Applied Energy Materials, 2, 9, 6536 – 6541, 2019
DOI: 10.1021/acsaem.9b01103.
[9] Efficient Photocatalytic CO2 Reduction by a Ni(II) Complex Having Pyridine Pendants through Capturing a Mg2+ Ion as a Lewis-Acid Cocatalyst,
Dachao Hong; Takuya Kawanishi; Yuto Tsukakoshi; Hiroaki Kotani; Tomoya Ishizuka; Takahiko Kojima, J. Am. Chem. Soc., 141, 51, 20309 – 20317, 2019
DOI: 10.1021/jacs.9b10597.
[8] Formation of a Ruthenium(V)-Imido Complex and the Reactivity in Substrate Oxidation in Water through Nitrogen-Non-Rebound Mechanism,
Tomoya Ishizuka; Taichi Kogawa; Misaki Makino; Yoshihito Shiota; Kazuaki Ohara; Hiroaki Kotani; Shunsuke Nozawa; Shin-ichi Adachi; KentaroYamaguchi; Kazunari Yoshizawa; Takahiko Kojima, Inorg. Chem., 58, 19, 12815 – 12824, 2019
DOI: 10.1021/acs.inorgchem.9b01781.

2018

[7] Formation and Isolation of a Four‐Electron‐Reduced Porphyrin Derivative by Reduction of a Stable 20π Isophlorin,
Wataru Suzuki; Hiroaki Kotani; Tomoya Ishizuka; Yoshihito Shiota; Kazunari Yoshizawa; Takahiko Kojima, Angew. Chem. Int. Ed., 57, 7, 1973 – 1977, 2018
DOI: 10.1002/anie.201711058.
[6] NH Tautomerism of a Quadruply-Fused Porphyrin: Rigid Fused Structure Delays the Proton Transfer,
Yuta Saegusa; Tomoya Ishizuka; Yoshihito Shiota; Kazunari Yoshizawa; Takahiko Kojima, J. Phys. Chem. B, 122, 1, 316 – 327, 2018
DOI: 10.1021/acs.jpcb.7b10945.
[5] A supramolecular photocatalyst composed of a polyoxometalate and a photosensitizing water-soluble porphyrin diacid for oxidation of organic substrates in water,
Tomoya Ishizuka; Shumpei Ohkawa; Hidemi Ochiai; Muneaki Hashimoto; Kei Ohkubo; Hiroaki Kotani; Masahiro Sadakane; Shunichi Fukuzumi; Takahiko Kojima, Green Chemistry, 20, 9, 1975 – 1980, 2018
DOI: 10.1039/C8GC00295A.
[4] Ruthenium(II) Complexes Having a Pincer‐Type Ligand with Two N‐Heterocyclic Carbene Moieties,
Yoshihiro Shimoyama; Tomoya Ishizuka; Hiroaki Kotani; Takahiko Kojima, Z. Anorg. Allg. Chem., 644, 14, 611 – 615, 2018
DOI: 10.1002/zaac.201800104.

2017

[3] Formation of Supramolecular Hetero-Triads by Controlling Hydrogen Bonding of Conjugate Bases with a Diprotonated Porphyrin based on Electrostatic Interaction,
Wataru Suzuki; Hiroaki Kotani; Tomoya Ishizuka; Yoshihito Shiota; Kazunari Yoshizawa; Takahiko Kojima, Chem. Commun., 53, 6359 – 6362, 2017
DOI: 10.1039/C7CC03635C.
[2] Thermodynamics and Photodynamics of a Monoprotonated Porphyrin Directly Stabilized by Hydrogen Bonding with Polar Protic Solvents,
Wataru Suzuki; Hiroaki Kotani; Tomoya Ishizuka; Kei Ohkubo; Yoshihito Shiota; Kazunari Yoshizawa; Shunichi Fukuzumi; Takahiko Kojima, Chem. Eur. J., 23, 19, 4669 – 4679, 2017
DOI: 10.1002/chem.201606012.
[1] Visible-Light-Driven Photocatalytic CO2 Reduction by a Ni(II) Complex Bearing a Bioinspired Tetradentate Ligand for Selective CO Production,
Dachao Hong; Yuto Tsukuakoshi; Hiroaki Kotani; Tomoya Ishizuka; Takahiko Kojima, J. Am. Chem. Soc., 139, 19, 6538 – 6541, 2017
DOI: 10.1021/jacs.7b01956.