A benzimidazole-based Cu(<sc>ii</sc>) complex catalyzed site-selective C-H sulfenylation of imidazo-[1,2-a]pyridines using CS2 as a sulfur source

A new benzimidazole-based Cu(ii) complex catalyzed site-selective sulfenylation of imidazo[1,2-a]pyridines with benzyl/alkyl/allyl bromides and CS2 at 100 degrees C in DMF : H2O is reported. The present methodology has been developed for the synthesis of 3-sulfenyl imidazo[1,2-a]pyridines in good yields with a broad substrate scope. In this protocol, CS2, commonly known as a non-polar small molecule bioregulator (SMB), is converted to valuable sulfenylated imidazo[1,2-a]pyridine derivatives. In addition, theoretical investigations along with experimental evidence unfold the insights into the probable mechanistic pathway of site-selective sulfenylation from S,S-dibenzyltrithiocarbonate, which is particularly formed as an intermediate during the reaction.