Tandem carbon-carbon bond constructions via catalyzed cyanation/Brook rearrangement/C-acylation reactions of acylsilanes.

[reaction: see text] A tandem nucleophile-catalyzed cyanation/Brook rearrangement/C-acylation has been developed. Phase transfer cocatalysts facilitate cyanide-catalyzed reactions between acylsilanes and cyanoformates to afford protected tertiary carbinol products. A catalytic cycle is proposed involving cyanation of an acylsilane, [1,2]-Brook rearrangement, and C-acylation of the derived carbanion by a cyanoformate ester. The reaction offers an efficient method for the preparation of functionalized, unsymmetrical malonic acid derivatives.