Copper-catalyzed sulfenylation of pyrroles with disulfides or thiols: directly synthesis of sulfenyl pyrroles

We present here the synthesis of sulfenyl pyrroles by copper-catalyzed sulfenylation of pyrroles with organic disulfides or thiols. The direct sulfenylation of pyrroles with organic disulfides has been accomplished in the presence of 3 mol % of CuI in DMSO at 110 °C under air atmosphere. In the other hand, sulfenylation of pyrroles with thiols were performed in the same solvent and temperature, however it is necessary 5 mol % of CuI and nitrogen atmosphere. Using these protocols we were able to produce 2-sulfenyl pyrroles in good to excellent yields and with high selectivity without use of any ligand or additive.