Synfacts 2008(3): 0287-0287  
DOI: 10.1055/s-2008-1042683
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

Boron-Based Reagent for Enantioselective Reduction of Ketones

Contributor(s):Hisashi Yamamoto, Marina Naodovic
S. Eagon, J. Kim, K. Yan, D. Haddenham, B. Singaram*
University of California, Santa Cruz, USA
Asymmetric Reductions Using the Chiral Boronic Ester TarB-H: A Practical and Inexpensive Procedure for Synthesizing Chiral Alcohols
Tetrahedron Lett.  2007,  48:  9025-9029  
Further Information

Publication History

Publication Date:
21 February 2008 (online)


Significance

Boron-derived reducing agents used for reduction of carbonyls represent a vast group of common reagents used in organic synthesis. Although several examples of boron-based enantioselective reduction have been reported, many of those methodologies still suffer from great difficulties. Described here is a highly stable and effective boron reagent for highly efficient enantioselective reduction of ketones.

Comment

The tartaric acid based boron-derived reagent is easily prepared and can be stored for extended periods of time. Under mild conditions, the reaction proceeds smoothly to give products in good yields and excellent enantioselectivities. It was also demonstrated that reactions can be carried out in air without any loss of reactivity and selectivity. For the above-mentioned reasons, this methodology represents a very useful alternative especially for the large-scale synthesis.