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Communication
Chiral Lithium Salts of Phosphoric Acids as Lewis Acid–Base Conjugate Catalysts for the Enantioselective Cyanosilylation of Ketones
Article first published online: 9 JUL 2008
DOI: 10.1002/adsc.200800314
Copyright © 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Additional Information
How to Cite
Hatano, M., Ikeno, T., Matsumura, T., Torii, S. and Ishihara, K. (2008), Chiral Lithium Salts of Phosphoric Acids as Lewis Acid–Base Conjugate Catalysts for the Enantioselective Cyanosilylation of Ketones. Adv. Synth. Catal., 350: 1776–1780. doi: 10.1002/adsc.200800314
Publication History
- Issue published online: 31 JUL 2008
- Article first published online: 9 JUL 2008
- Manuscript Received: 20 MAY 2008
Funded by
- JSPS
- KAKENHI. Grant Number: 20245022
- Grant-in-Aid for Young Scientists B of MEXT. Grant Number: 19750072
- G-COE Program of MEXT
- Toray Science Foundation
Keywords:
- asymmetric catalysis;
- cyanohydrins;
- cyanosilylation;
- ketones;
- lithium;
- phosphoric acids
Abstract
The catalytic enantioselective cyanosilylation of aromatic ketones was developed by using chiral lithium salts of (R)-BINOL- or (S)-BINAM-derived phosphoric acid compounds. In the presence of 10 mol% of chiral conjugate lithium salts, the corresponding tertiary cyanohydrins were obtained in high yields with moderate to high enantioselectivities. This is the first efficient example of asymmetric catalysis using lithium salts of synthetically useful chiral phosphoric acid compounds. A possible catalytic mechanism and transition states are also discussed as a preliminary working hypothesis.