A simple, base-free preparation of S-aryl thioacetates as surrogates for aryl thiols

A mild method for the preparation of S-aryl thioacetates by hetero cross-coupling reactions of aryl bromides or aryl triflates with potassium thioacetate is described. The reaction proceeded smoothly in toluene at 110 °C, mediated by catalytic Pd2(dba)3 in combination with CyPF-tBu as the ligand. Neither the presence of a base nor microwave conditions were required. The formed S-aryl thioacetate proved to be stable under flash chromatographic conditions and could be rapidly converted into the corresponding thiol under mildly basic conditions.

Aryl bromides and aryl triflates are easily converted into the corresponding stable S-aryl thioacetates by a palladium-catalyzed hetero cross-coupling reaction. Subsequent mild deprotection to the corresponding thiol enables further functionalization.