A simple and efficient copper-catalyzed procedure for the hydrosilylation of hindered and functionalized ketones

The catalytic hydrosilylation of highly hindered and functionalized ketones is described. The combination of inexpensive catalyst precursors, CuCl and NHC-HX (NHC = N-heterocyclic carbene), leads to a highly efficient reduction mediator for the preparation of silyl ethers from unfunctionalized and functionalized alkyl, cyclic, bicyclic, aromatic, and heteroaromatic ketones. A series of catalyst precursors have been structurally characterized and a catalyst-structure activity relationship is discussed.