Catalytic reduction of imines with silylformates: Formation of silyl carbamates through CO2 insertion

Silylformates are emerging surrogates of hydrosilanes, able to reduce carbonyl groups in transfer hydrosilylation reactions, with the concomitant release of CO2. In this work, a new reactivity is revealed for silylformates, in the presence of imines. Using ruthenium catalysts, and lithium iodide as a co-catalyst, imines are shown to undergo hydrocarboxysilylation by formal insertion of CO2 to the N-Si bond of silyl amine to yield silyl carbamates in excellent yields.