Hydrosilylation Catalyzed by the [Silica]-SMAP-Rh System

Significance

The compact phosphine 3 was immobilized on silica gel, which was found to be a highly effective ligand for the Rh-catalyzed hydrosilylation of various ketones. TfO-SMAP 2 was prepared via the protodesilylation of 1, and was covalently anchored onto HCl-activated silica gel to give [silica]-SMAP 3. The immobilized phosphine 3 was used as a ligand in the Rh-catalyzed hydrosilylation of ketones 4 where the corresponding silyl ethers 5 were obtained with excellent yields. The Rh-3 catalyst could be recoverd by simple filtration and be reused without loss of cata­lytic activity.