A benzimidazole-based Cu() complex catalyzed site-selective C-H sulfenylation of imidazo-[1,2-]pyridines using CS 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 CS 2 at 100 °C in DMF : H 2 O 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, CS 2 , 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. A benzimidazole-based Cu( ii ) complex catalyzed site-selective sulfenylation reaction using CS 2 as a sulfur surrogate is reported.