Catalyst‐Free Selective Desulfurization of Thioamides in Water and an Open System

The selective reduction of the unsaturated substrates in green solvent is highly desired yet however, remains a long‐standing challenge. Especially the selective desulfurization of thioamides usually requires hazardous highly reactive reagents or transition metal catalysts in high‐pressure conditions. Herein, a novel protocol of selective desulfurization of thioamides to amines with dimethylaminoborane (DMAB) without catalysts, operating in neat water under an open system, is presented. Notably, the selectivity of the reaction is effectively controlled with a simple Lewis acid additive through computational design. The combination of density functional theory and experimental mechanism studies reveals the important synergistic cooperation by DMAB and Lewis acid additive to facilitate the hydrogenative desulfurization process in an aqueous solution.