1996 Fiscal Year Final Research Report Summary
Enantioface-Differentiating Protonation with Chiral Charcogen Compounds on the Basis of Original Molecular Design
| Project/Area Number |
07672261
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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 |
Chemical pharmacy
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| Research Institution | TOYAMA MEDICAL AND PHARMACEUTICAL UNIVERSITY |
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Principal Investigator |
TAKAHASHI Tamiko Toyama Medical & Pharmaceutical University, Faculty of Pharmaceutical Sciences, Research Associate, 薬学部, 助手 (10115181)
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| Project Period (FY) |
1995 – 1996
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| Keywords | chiral selenoxide / gamma-hydroxyselenoxide / asymmetric protonation / prochiral enolate / ZnBr / intramolecular hydrogen bonding / chelation effect |
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| Research Abstract |
1. We have developed a facile method for the preparation of arylselenoxides having electron-withdrawing or electron-donating group.
2. An optically pure gamma-hydroxyselenoxide was available for a chiral proton source (CPS).
3. Enantioselectivity of this reaction was improved by introduction of an electron-donating group to benzene ring of CPS.4-Methoxy group was the most effective.
4. Reaction of zinc bromide enolates of 2-benzyl-and 2-n-propylcyclohexanones with (S_<Se>) -selenoxide (Ar=p-MeOC_6H_4) gave (S) -2-benzylcyclohexanone and (R) -2-n-propyl-cyclohexan-one in 89% ee and 88%ee, respectively.
5. This asymmetric induction is probably due to intramolecular hydrogen bonding between hydroxy group and seleninyl-oxygen as well as chelation effects among hydroxy group, seleninyl-oxygen and metal enolate.
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