127 - Novel Catalyst for Enantioselective Cyanosilylation of Aldehydes and Ketones Using Partially Hydrolyzed Titanium Alkoxide as a Lewis Acidic Metal

Abstract

Highly enantioselective cyanosilylation of aldehydes and ketones to the corresponding cyanohydrins was developed in the presence of an optically active titanium catalyst. This enantioselective cyanation was carried out using partially hydrolyzed titanium alkoxide as a Lewis acidic metal. The reactions between aldehydes and trimethylsilyl cyanide proceeded rapidly in high yields at room temperature, and its cyanohydrin trimethylsilyl ethers were obtained in 0.5-2 hours in high enantioselectivities using 0.2 mol% of the titanium catalyst. This catalytic system was successfully applied to the asymmetric cyanosilylation of ketones.