TBAI-mediated sulfenylation of arenes with arylsulfonyl hydrazides in DPDME

An efficient TBAI (tetrabutylammonium iodide)-mediated C–H sulfenylation of arenes with arylsulfonyl hydrazides in dipropylene glycol dimethyl ether (DPDME) was described. Various electron-rich arenes were applicable in the reaction, such as naphthylamine, naphthol, aniline, indole, pyrrole, and imidaz o [1,2-a] pyridine. A wide range of the aryl sulfides were obtained with good functional group tolerance. This method features green reaction conditions (odorless and easily available sulfur reagent, recyclable TBAI, and DPDME as solvent), and broad substrate scope. The synthetic potential is demonstrated by gram-scale synthesis and downstream transformations. The mechanism studies show that the reaction is achieved through electrophilic substitution process, and diaryl disulfide may be the main intermediate.