Synfacts 2007(7): 0722-0722  
DOI: 10.1055/s-2007-968669
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

Spiroborate-Catalyzed Asymmetric Borane Reduction of Oxime Ethers

Contributor(s): Hisashi Yamamoto, Joshua N. Payette
X. Huang, M. Ortiz-Marciales*, K. Huang, V. Stepanenko, F. G. Merced, A. M. Ayala, W. Correa, M. De Jesús
University of Puerto Rico, Humacao, Puerto Rico
Further Information

Publication History

Publication Date:
22 June 2007 (online)

Significance

The authors report the first truly catalytic, asymmetric borane-mediated reduction of oxime ethers. Prior to this work, high enantioselectivities could only be obtained by using stoichio­metric amounts of oxazaborolidines as the chirality transfer reagent. Spiroborate ester 1 is able to catalyze the reduction of (E)-benzyl oxime ethers derived from acyclic as well as cyclic ketones in good yields with high ee values.