Visible light-induced aerobic oxidative cross-coupling of glycine esters with -angelicalactone: a facile pathway to -lactams

A metal-free aerobic oxidative dehydrogenative formal [2 + 3] cyclization of glycine esters with -angelicalactone has been accomplished via the synergistic combination of photoredox catalysis and acid catalysis. This protocol provides straightforward and facile access to a series of substituted -lactams at room temperature under an air atmosphere. Moreover, the reaction could be carried out on a gram scale. The mild conditions as well as the use of cheap substrates and catalyst make this protocol very attractive for further synthetic applications.