Visible-light-promoted tandem decarboxylation coupling/cyclization of N-aryl glycines with quinoxalinones: Easy access to tetrahydroimidazo[1,5-a]quinoxalin-4(5H)-ones

Abstract

A visible-light-promoted formal [2 ​+ ​2 + 1] cyclization of N-aryl glycines with quinoxalin-2(1H)-ones to synthesize tetrahydroimidazo[1,5-a]quinoxalin-4(5H)-ones have been developed. The protocol features operational simplicity, mild reaction conditions with blue LED light employing Ru(bpy)₃Cl₂^.6H₂O as a photoredox catalyst, a combination of O₂ from air and Cu(OAc)₂ as the oxidant and broad substrate applicability.