2019 Fiscal Year Final Research Report
Design and Creation of New Chiral Reaction Environment Utilizing Helical Macromolecular Architectures
| Project Area | Precise Formation of a Catalyst Having a Specified Field for Use in Extremely Difficult Substrate Conversion Reactions |
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| Project/Area Number |
15H05811
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| Research Category |
Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
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| Allocation Type | Single-year Grants |
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| Review Section |
Science and Engineering
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| Research Institution | Kyoto University |
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Principal Investigator |
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| Project Period (FY) |
2015-06-29 – 2020-03-31
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| Keywords | 不斉合成 / 高分子触媒 / 不斉増幅 / キラル溶媒 / らせん高分子 / 動的キラリティ / キラル触媒 / キラリティスイッチング |
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| Outline of Final Research Achievements |
This study revealed that the helical poly(quinoxaline-2,3-diyl) scaffold provides highly effective chiral reaction environments for asymmetric catalysis, of which enantioselectivities are comparable or even superior to those obtained with low-molecular-weight chiral catalysts. Generality of the PQX scaffold as chiral catalysts was demonstrated by incorporation of various chiral catalyst pendants on the basis of copolymerization protocol, leading to the application to a wide array of asymmetric reactions with high enantioselectivities. The dynamic nature of the PQX scaffolds allows "chirality-amplifying" asymmetric catalysis in which chiral molecules with low enantiomeric excesses or those having weak nonbonding molecular interaction are used as sources of chirality. Through this research program, new possibilities of helical polymer scaffolds as a novel type of catalysts for asymmetric catalysis have been successfully demonstrated.
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| Free Research Field |
有機合成化学
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| Academic Significance and Societal Importance of the Research Achievements |
右巻き構造と左巻き構造を速やかに反転させることを特徴とする新しいポリマーを開発し、そのらせん構造中に触媒活性部位を導入することで、鏡像異性体の一方を高い選択性で与える優れた触媒機能を確立した。触媒活性部位の構造を変化させることで、全く異なった反応機構で進む様々な反応に対応した触媒を作り出すことができた。また、右巻きと左巻きの区別がないポリマーに対して、天然に由来する鏡像異性体化合物を後で添加することで、右巻きおよび左巻き構造を完全に誘起することができた。これを利用し、オレンジの皮から大量に得られる(R)-リモネン等のキラル溶媒を唯一の不斉源とする不斉合成反応の開発に世界で初めて成功した。
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