Straightforward and highly efficient catalyst-free regioselective reaction of thiol to β-nitrostyrene: a concise synthesis of vinyl sulfide and nitro sulfide

Under catalyst-free reaction conditions, solvent-mediated addition of thiol 2 to β-nitrostyrene 1 proceeded with regioselective control to afford either adduct 3 or vinyl sulfide 4 in good to excellent yield. Thermodynamic and autocatalytic reaction mechanisms were proposed to rationalize the products thus formed.