Synthesis of Thiol Esters Using PhSZnBr as Sulfenylating Agent: A DFT-Guided Optimization of Reaction Conditions

The use of PhSZnBr as sulfenylating agent in a solvent-free protocol to prepare thiol esters in excellent yields from acyl chlorides is reported. The products were efficiently obtained by grinding the neat reagents for 5 min in a mortar. DFT calculations showed that the coordination of solvent molecules to the metal center of PhSZnBr results in the destabilization of the frontier MOs, thus reducing the reactivity towards the acyl chloride compared with solvent-free conditions. A possible mechanism based on the coordination of the carbonyl group of the acyl chloride to the metal center of PhSZnBr is proposed.