Metal-free electrochemical C3-sulfonylation of imidazo[1,2-: A] pyridines

Electrochemical oxidative cross-coupling represents one of the most atom-economical and green approaches to synthesize various useful compounds. In this work, an electrochemical C3-sulfonylation of imidazo[1,2-A]pyridines with sodium benzenesulfinates as sulfonylation reagents has been developed. This transformation provides an effective and straightforward metal-free protocol towards the synthesis of biologically and synthetically useful 3-(arylsulfonyl)imidazo[1,2-A]pyridine. Up to 94% yields were obtained. The scale-up experiment gave 1.56 g of the desired product in 90% yield.