Catalytic asymmetric cyanosilylation of ketones, aldehydes, thioketones, thioaldehydes, imines and hydrazones

摘要

One aspect of the present invention relates to a method for the catalytic asymmetric cyanosilylation of ketones, aldehydes, thioketones, thioaldehydes, imines and hydrazones. The critical elements of the method are: a non-racemic chiral tertiary-amine-containing catalyst; a substrate selected from the group consisting of ketones, aldehydes, thioketones, thioaldehydes, imines and hydrazones; and a silyl cyanide, e.g., trimethylsilyl cyanide. In preferred embodiments, the substrate is a ketone or aldehyde. A preferred embodiment of the present invention relates to practicing the method in a halocarbon solvent, e.g., chloroform. Another preferred embodiment of the present invention ,relates to practicing the method in an ester solvent, e.g., ethyl acetate. In certain embodiments, the methods of the present invention produce a silyl cyanohydrin with an enantiomeric excess greater than about 80%. In certain embodiments, the methods of the present invention produce a silyl cyanohydrin with an enantiomeric excess greater than about 90%.