Rhodium(I)-Catalyzed Highly Enantioselective Insertion of Carbenoid into Si–H: Efficient Access to Functional Chiral Silanes

The first rhodium­(I)-catalyzed enantioselective Si–H insertion reaction of α-diazoesters and α-diazophosphonates has been developed. The use of a C₁-symmetric chiral diene ligand enabled the asymmetric reaction to proceed under exceptionally mild conditions and give versatile chiral α-silyl esters and phosphonates with excellent enantioselectivities (up to 99% ee). The mechanism and stereochemical pathway of this novel Rh­(I)-carbene-directed Si–H insertion was investigated by deuterium kinetic isotope effect experiments and DFT calculations.