Enantioselective Cyanosilylation of Ketones Catalyzed by a Nitrogen-Containing Bifunctional Catalyst

An efficient and optically active, bifunctional tetraaza ligand (2S)‐N‐{(1R,2R)‐2‐[(S)‐pyrrolidine‐2‐carboxamido]‐1,2‐diphenylethyl}pyrrolidine‐2‐carboxamide has been developed for the addition of trimethylsilyl cyanide (TMSCN) to ketones. The bifunctional catalyst system based on a monometallic titanium complex was found to be a highly enantioselective catalyst to provide O‐TMS cyanohydrins with up to 94% ee. A possible transition state has been proposed to explain the origin of the activation and asymmetric inductivity.