One-Pot Synthesis of 5-Acyl-1,2,3-Thiadiazoles from Enaminones, Tosylhydrazine, and Elemental Sulfur under Transition-Metal-Free Conditions

I2/dimethyl sulfoxide (DMSO)-mediated C–S, S–N, and C–N bond cross-coupling cyclization reaction for the synthesis of 5-acyl-1,2,3-thiadiazoles from enaminones, tosylhydrazine, and elemental sulfur has been developed under transition-metal-free conditions. This strategy is operationally simple, compatible with a wide range of functional groups, and provides the desired products in moderate to excellent yields.