Cu-catalyzed sulfenylation of imidazol[1,2-a]pyridine via C–H functionalization using a combination of Na 2 S 2 O 3 and halides

A novel copper-catalysed sulfenylation method by using the inorganic salt Na 2 S 2 O 3 and alkyl halides (Cl, Br, I) or iodobenzene homologues is described. The reactions proceeded smoothly, giving regioselective 2-phenylimidazo[1,2- a ]pyridine thioether derivatives in good yields via a C–H functionalization process. More importantly, this method has extended the existing methods by offering a better method which can make both alkyl and aryl thioether derivatives under one set of reaction conditions.