Deoxygenative Silylation of C(sp3)–O Bonds with Hydrosilane by Cooperative Catalysis of Gold Nanoparticles and Solid Acids

Abstract

Efficient deoxygenative silylation of C(sp3)–O bonds with hydrosilanes by supported Au catalysts is described. Gold nanoparticles supported on TiO2 enabled various hydrosilanes to be used as sources of silyl groups in C–Si cross-coupling reactions. A variety of alkyl acetates and propargyl carbonates participated in the Au-catalyzed reactions to furnish the corresponding alkyl and allenylsilanes in high yields. In addition, Au/TiO2 was also effective for ring-opening silylation of cyclic ethers. A detailed mechanistic investigation corroborated that the title reaction involves the formation of silyl and alkyl radical intermediates, and the cooperation of Au nanoparticles as single-electron transfer catalysts and Lewis acid sites at the surface of metal oxides was responsible for the unusual reactivity of hydrosilanes for specific C(sp3)–Si bond formation.