Rhodium-Catalyzed Highly Regioselective and Stereoselective Intermolecular Hydrosilylation of Internal Ynamides under Mild Conditions

A rhodium-catalyzed highly regio- and stereoselective intermolecular hydrosilylation of internal ynamides has been developed. With the neutral rhodium complex [Rh­(CO)₂Cl]₂ as a catalyst and the bulky silanes as reactants, various ynamides underwent hydrosilylation smoothly at room temperature with an excellent β-regioselectivity and <i>anti</i>-stereoselectivity. The synthetically versatile β-silyl (<i>Z</i>)-enamide products could be further transformed to diverse useful building blocks. Several possible mechanisms are proposed to rationalize this unique formal <i>trans</i>-addition-type selectivity