A Convenient Catalytic Procedure for the Addition of Trimethylsilyl Cyanide to Functionalised Ketones, Mediated by InBr3 − Insight into the Reaction Mechanism

This paper describes a useful and practical methodology for the addition of trimethylsilyl cyanide (TMSCN) to a large variety of functionalised and unfunctionalised ketones in the presence of catalytic amounts of anhydrous InBr3. The optimum procedure involves low catalyst loading (1 mol %) and appears general in scope and applicability for aromatic and aliphatic ketones. The desired cyanohydrins were typically isolated as their O-silyl ethers in good to excellent chemical yields (up to 99%). Kinetic and spectroscopic studies suggest that a catalytically active dimeric indium species is involved in the reaction mechanism. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)