Reaction of acylsilanes with potassium cyanide: Brook rearrangement under phase-transfer catalytic conditions

The reactions of acylsilanes with KCN under liquid–liquid phase-transfer catalytic conditions proceeded smoothly via the Brook rearrangement to produce O-silylated cyanohydrin derivatives in excellent yields. We also found that α-cyano carbanions generated by the Brook rearrangement in the reaction of (β-(trimethylsilyl)acryloyl)silane 7 can undergo alkylation at the γ-position and that in the reaction of β-bromoacylsilane 14 intramolecular alkylation occurs to afford cyclopropanone cyanohydrin derivative 16.