Corey-Bakshi-Shibata Reduction
Itsuno-Corey Reduction

The enantioselective reduction of ketones using borane and a chiral oxazaborolidine as catalyst (CBS catalyst). Usually, MeCBS is used (R'' = Me, but selectivity may be increased by varying this substituent).

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Mechanism

The mechanism depicted portrays the rationale for the enantioselectivity and high reaction rates, which are influenced only by the CBS catalyst. This catalyst is a combination of both a Lewis acid and a chiral auxiliary!

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Recent Literature

An Efficient and Catalytically Enantioselective Route to (S)-(-)-Phenyloxirane
E. J. Corey, S. Shibata, R. K. Bakshi, J. Org, Chem., 1988, 53, 2861-2863.

A Catalytic Enantioselective Synthesis of the Endothelin Receptor Antagonists SB-209670 and SB-217242. A Base-Catalyzed Stereospecific Formal 1,3-Hydrogen Transfer of a Chiral 3-Arylindenol
W. M. Clark, A. M. Tickner-Eldridge, G. K. Huang, L. N. Pridgen, M. A. Olsen, R. J. Mills, I. Lantos, N. H. Baine, J. Am. Chem. Soc., 1998, 120, 4550-4551.