1997 Fiscal Year Final Research Report Summary
Origin of Regio and Stereoselectivity in Conjugate Addition Reactions
| Project/Area Number |
07457520
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Chemical pharmacy
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| Research Institution | KYOTO UNIVERSITY (1996-1997)
Osaka University (1995) |
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Principal Investigator |
TOMIOKA Kiyoshi KYOTO UNIVERSITY Gradate School of Pharmaceutical Sciences, Professor, 薬学研究科, 教授 (50114575)
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| Co-Investigator(Kenkyū-buntansha) |
NAGAOKA Yasuo KYOTO UNIVERSITY,Gradate School of Pharmaceutical Sciences, Instructor, 薬学研究科, 助手 (90243039)
IIDA Akira KYOTO UNIVERSITY,Gradate School of Pharmaceutical Sciences, Associate Professor, 薬学研究科, 助教授 (40202816)
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| Project Period (FY) |
1995 – 1997
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| Keywords | enantioselective reaction / conjugate addition / imine / lithium enolate / LUMO coefficients / ligand / catalytic reaction / beta-lactam |
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| Research Abstract |
We have reported the successful chiral ligand-mediated asymmetric 1,2- and 1,4-addition reactions of organolithiums to various imines of aryl and alpha, beta-unsaturated aldehydes Thus, organo-lithiums add to the cyclohexylimines 1,2 (R=c-C6Hll) in 1,4-fashion to give, after hydrolysis, the corresponding aldehydes in up to 99% ee and in high to good yields. On the other hand, the reactions with arylimines exclusively afford 1,2-adducts in up to 90% ee and in nearly quantitative yields, giving us a good method for the preparation of chiral amines. It is also interesting in that the reactions with both cyclohexyl- and arylimines of 1-fluoronaphthalene-2-carbaldehyde exclusively proceed in 1,4-fashion to provide nucleophilic aromatic substitution products in high yields. Since deep understanding of the factors governing regioselectivity is a long-standing problem and essential for further development of the much more effective catalytic asymmetric reactions of the ene-imines. we carried out molecular orbital calculations and revealed that the experimentally observed regioselectivity is rationalized by the relative magnitude of the LUMO coefficients.
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