Carbonyl-Stabilized Phosphorus Ylide as an Organocatalyst for Cyanosilylation Reactions Using TMSCN

We report carbonyl-stabilized phosphorus ylides as general and efficient catalysts for the cyanosilylation of ketones. The N,N-diethylacetamide derived phosphorane is identified as an extremely efficient catalyst for the cyanosilylation of dialkyl ketones, alkyl aryl ketones, diaryl ketones, and α,β-unsaturated enones with catalyst loading down to 0.005 mol %, the lowest ever known for ketone cyanosilylation. Aldehydes, aldimines, and ketimines are also viable substrates. By NMR and React IR analysis, as well as electrical conductivity experiments, it is proposed that the phosphorane acts as a Lewis base in order to mediate the reaction via the desilylative nucleophilic activation of TMSCN.