I(2)-catalyzed intramolecular oxidative amination of C(sp(3))–H bond: efficient access to 3-acylimidazo[1,2-a]pyridines under neat condition

An efficient and “green” protocol for the synthesis of 3-acylimidazo[1,2-a]pyridines through intramolecular oxidative α-amination of carbonyl compounds has been developed. The reaction proceeds smoothly utilizing I(2) as a catalyst and H(2)O(2) as an oxidant under neat condition with broad substrate scope. Several complex nitrogen-containing fused rings are conveniently constructed, which are not easy to access by traditional methods.