Regioselective thiolation of electron rich arenes and heterocycles in recyclable catalytic media

A convenient and novel approach has been developed for the synthesis of unsymmetrical diaryl sulfides by the reaction of sulfonyl hydrazides with phenols using a [Bmim][Br] ionic liquid through the formation of C–S bonds. The reaction has further been extended to indole, β-naphthol and aromatic amine moieties. This protocol offers a new, versatile and greener approach for thiolation of natural phenols (monoterpenes)/aromatic phenols/β-naphthols/aromatic amines and indoles without using any catalyst. A broad range of functional groups were well tolerated in this reaction system.