Electrochemical sulfonylation of imidazoheterocycles under batch and continuous flow conditions

Abstract

An efficient and versatile protocol for the C–H sulfonylation of imidazoheterocycles via electrochemical activation was established under batch and flow conditions. The selective C–H bond functionalization proceeded under catalyst- and oxidant-free conditions and tolerated a wide range of functional groups. Various sodium sulfinates as well as imidazo[1,2-a]-pyridines, -pyrimidine, -quinolines, and -isoquinolines, imidazo[1,2-b]pyridazine, imidazo[2,1-b]thiazoles and benzo[d]imidazo[1,2-b]thiazoles reacted successfully. Interestingly, significant acceleration and higher yields were obtained under microfluidic conditions.