N-tert-Butyldimethylsilyl Imines as Intermediates for the Synthesis of Amines and Ketones

Abstract

Grignard reagents add to benzonitrile at low temperature catalyzed by CuBr and TBSCl affording N-TBS ketimines, which were investigated as intermediaries for the synthesis of primary amines and ketones. N-silylimines were easily obtained by an organolithium addition to benzonitrile followed by a reaction with TBSCl in CH2Cl2. In situ reduction of these imines by BH3 and 1,3,2-oxazaborolidines 1 or 2 as chiral templates afforded the corresponding amines with modest to good enantiomeric excess.