Copper-catalyzed silylation of activated alkenes by photoinduced ligand-to-metal charge transfer

A CuCl$_2$-mediated hydrosilylation of activated olefins with hydrosilanes under visible-light irradiation is reported. The photoactive CuCl$_2$ undergoes a ligand to metal charge transfer, generating a chlorine radical, which abstracts an hydrogen from the hydrosilane, forming a silyl radical, which then adds to the activated olefin. The reaction provides the corresponding carbosilanes in generally good yield under practically simple and mild conditions.