Direct C–H bond activation of ethers and successive C–C bond formation with benzene by a bifunctional palladium–titania photocatalyst

Abstract

Palladium-loaded titanium oxide was found to work as a bifunctional photocatalyst for functionalization of benzene with ether upon photoirradiation, without using any special reagents. The metal-loaded TiO₂ photocatalyst activated a C–H bond of ethers and the heterogeneous Pd metal nanoparticle catalyst promoted the successive C–C bond formation between benzene and the radical species. In this reaction, benzene reacted very selectively with the α-carbon of various ethers at least in the initial stage of the reaction. Kinetic and ESR studies revealed a detailed mechanism for the reaction.