1997 Fiscal Year Final Research Report Summary
Development and Application of Chiral Ligands Bearing Hetero-functional Groups for Neighboring Participation
| Project/Area Number |
08457587
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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 | University of Shizuoka |
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Principal Investigator |
ACHIWA Kazuo University of Shizuoka, School of Pharmaceutical Sciences, Professor, 薬学部, 教授 (10012626)
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| Co-Investigator(Kenkyū-buntansha) |
MORIMOTO Toshiaki University of Shizuoka, School of Pharmaceutical Sciences, Associated Professor, 薬学部, 助教授 (60046307)
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| Project Period (FY) |
1996 – 1997
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| Keywords | chiral ligand / chiral catalyst / palladium catalyst / rhodium catalyst / asymmetric allylation / asymmetric hydrogenation / neighboring group |
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| Research Abstract |
Novel chiral 1,4- and 1,2-bisphoshine ligands [BHMP-7X and NORPHOS-7X(or 5X)] which have a norbornane skeleton bearing hetero-functional groups syn to the phosphino groups for neighboring participation were efficiently prepared by using stereospecific rearrangement of the framework, and it was found that the neighboring hetero-functional groups have dramatic effects on the enantioselection in several transition metal-catalyzed asymmetric reactions. A BHMP-7-X bearing a beta-alanine branch efficiently improved the enantio-selectivity in palladium-catalyzed allylic alkylation and aminations ; these results indicate that the carboxyl group of the ligand efficiently interacts with the nucleophiles. The neighboring amino group of another ligands, NORPHOS-7-NEt_2 and -5-NEt_2, gave unexpected effects on the enatioselection in palladium-catalyzed asymmetric allylation of malonate. The complete reversal chirality (-99%ee) of the regands was observed in contrast to the enantioselectivity of the original NORPHOS.On the other hand, a NORPHOS-7X bearing a carboxyl group showed also reversal chirality in rhodium-catalyzed asymmetric hydrogenation of N-benzoylhydrazone, although no clear effects of neighboring groups on the enantioselection in rhodium-catalyzed asymmetric hydrogenation of N-acyldehydroamino acids were observed.
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