Stable and readily available N,N'-di-Boc-substituted thiourea, when activated with trifluoroacetic acid anhydride, was used as a novel thioacylating agent. Through the thioacylation of nucleophiles, such as amines, alcohols, thiols, sodium benzenethiolate, and sodium malonates with N,N'-di-Boc-substituted thiourea, a series of thiocarbonyl compounds were prepared under mild conditions with good chemical selectivity and functional group tolerance.