Copper(I) Iodide/Boron Trifluoride Etherate-Cocatalyzed Aerobic Dehydrogenative Reactions Applied in the Synthesis of Substituted Heteroaromatic Imidazo[1,2-a]pyridines

Compared with the well-known palladium-catalyzed oxidative dehydrogenation coupling reactions, similar transforms initiated by copper/oxygen have attracted more and more attention. We have investigated a novel construction of heteroaromatic imidazo[1,2-a]pyridines through copper(I) iodide/boron trifluoride etherate/oxygen-mediated dehydrogenative reactions of aryl alkyl or alkyl alkyl ketones with 2-aminopyridines. Four hydrogen atoms are removed and two new CN bonds are formed in one step via the imine formation and oxidative C(sp(3))H functionalization.