Iridium-Catalyzed Reduction of Secondary Amides to Secondary Amines and Imines by Diethylsilane

Catalytic reduction of secondary amides to imines and secondary amines has been achieved using readily available iridium catalysts such as [Ir­(COE)2Cl]2 with diethylsilane as reductant. The stepwise reduction to secondary amine proceeds through an imine intermediate that can be isolated when only 2 equiv of silane is used. This system requires low catalyst loading and shows high efficiency (up to 1000 turnovers at room temperature with 99% conversion have been attained) and an appreciable level of functional group tolerance.