2006 Fiscal Year Final Research Report Summary
Development of Asymmetric Carbon-Carbon Bond Formation Catalyzed by Chiral Bronsted Acid Based on Molecular Recognition Approach
| Project/Area Number |
17350042
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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 |
Synthetic chemistry
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| Research Institution | Tohoku University |
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Principal Investigator |
TERADA Masahiro Tohoku University, Graduate School of Science, Professor, 大学院理学研究科, 教授 (50217428)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Asymmetric Synthesis / Catalyst / Molecular Transformation / Bronsted Acid / Molecular Recognition / Hydrogen Bonding / Environmentally Benign / Selective Synthesis |
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| Research Abstract |
Much effort has been directed towards the development of highly efficient and selective organic transformations. In particular, considerable attention has been devoted to create a novel catalyst with high performance to accelerate organic transformations in highly stereoselective manner. Bronsted acid catalysts have been utilized in valuable organic transformations. If the enantioselective catalysis by chiral Bronsted acid would be accomplished, this provides an advanced approach to the Bronsted acid catalysis. The purpose of this research project is the development of efficient and selective chiral Bronsted acid catalysis for useful organic transformations.
We have previously reported the enantioselective direct Mannish reaction catalyzed by chiral phosphoric acids derived form optically pure binahthol derivatives. In our continued studies for the chiral Bronsted acid catalysis, herein we report recent advance in this research project, especially for the development of efficient and enantioselective carbon-carbon bond forming reactions. We developed highly enantioselective Friedel-Crafts reaction of imines with diazoacetates to give a-substituted products of diazoacetates in high enentioselectivity. Second, we have also developed highly enantioselective aza-ene type reaction of imines with enecarbamate as a nucleophile. In the aza-ene type reaction, we successfully demonstrated that the aza-ene type reaction took place efficiently with lowering the load of the chiral catalyst, less than 0.1 mol%. Furthermore, taking advantage of the nature of the present phosphoric acid catalyst as the Bronsted acid, we also successfully developed the first enantioselective Friedel-Crafst reaction of electron rich alkenes with aromatic compounds. The reaction of enecarbametes as electron rich alkenes with indoles gave the corresponding products in high enantioselectivity.
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