Efficient, Eco-Friendly and Regioselective Method for Thiolysis of 1,2-Epoxides with Diaryl Disulfides in the Presence of Zn/Bi(TFA)3-TBPB or Zn/Bi(OTf)3-TBPB

Diaryl disulfides undergo regioselective ring-opening of 1,2-epoxides in the presence of zinc powder and 3-4 mol-% of bismuth(III) trifluoroacetate or 1 mol-% of bismuth(III) triflate in molten tetrabutylphosphonium bromide (TBPB) to afford the corresponding β-hydroxy thioethers in good to excellent yields.