1998 Fiscal Year Final Research Report Summary
Development of Catalytic Asymmetric Synthesis of Optically Active beta-Hetero-alpha-amino Acids
| Project/Area Number |
09650935
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
有機工業化学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
KUWANO Ryoichi Kyoto University, Graduate School of Engineering, Assistant Professor, 工学研究科, 助手 (20273477)
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| Project Period (FY) |
1997 – 1998
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| Keywords | Catalytic Asymmetric Synthesis / alpha-Amino Acid / beta-Hydroxy-alpha-amino Acid / alpha, beta-Diamino Acid / Piperazine-2-carboxylic Acid / Optically Active Compound / Rhodium Catalyst / Chiral Diphosphine Ligand |
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| Research Abstract |
Optically active alpha-amino acids attached a hetero atom on the beta-carbon atom are important as not only constituents of many biologically active peptides but also chiral building blocks for syntheses of useful compounds. In this study, the author developed some new catalytic asymmetric syntheses of optically active beta-hetero-alpha-amino acids.
1. Stereoselective Synthesis of beta-Hetero-alpha-acetamldoacrylates. alpha-Acetamidoacrylates bearing a heterosubstituent at the beta-position were synthesized from the corresponding beta-keto-alpha- acetamidoacrylates. Both of the geometrical isomers were possible to be prepared with perfect stetreoselectivity.
2. Catalytic Asymmetric Hydrogenation of beta-Hetero-alpha-acetamidoacrylates. The beta-hetero-alpha- acetamidoacrylates thus obtained were hydrogenated with high enantioselectivity (up to 97% ee) by a chiral rhodium catalyst possessing a trans-chelating chiral diphosphine TRAP, which had been developed by the authors. threo- and erythro-beta-Hetero-alpha-amino acids were obtained with complete stereospecificity and high enantioselectivity from the (E)- and (Z)-substrates, respectively.
3. Catalytic Asymmetric Synthesis of Cyclic beta-Hetero-alpha-amino acids. The TRAP-rhodium catalysts were also effective for asymmetric hydrogenations of tetrahydropyrazine-2-carboxamides, giving (S)-piperazine-2-(N-tert-butyl)carboxamides with up to 97% ee, which are important for the synthesis of HIV protease inhibitor Crixivan. Of interest is that both of the enantiomers with high enantiomeric excess were possible to be obtained by two chiral catalysts derived from a single chiral source.
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