SiO2-Supported Rh Catalyst for Efficient Hydrosilylation of Olefins Improved by Simultaneously Immobilized Tertiary Amines

The simultaneous immobilization of a Rh complex and a tertiary amine on a SiO2 surface afforded a highly active supported catalyst for the hydrosilylation of terminal olefins. The turnover number in the reaction using 0.00005 mol % of the Rh catalyst approached 1 900 000 over 24 h. A broad range of terminal olefins and hydrosilanes acted as good substrates, giving their corresponding hydrosilylation products in excellent yields. CSI-mass analysis of the precursor solution containing the Rh complex and tertiary amine indicated complexation between these two precursors. The resultant close positioning of the Rh complex and amine after attachment onto SiO2 surface led to excellent catalysis.