Synthesis of [1,2,3]Triazolo-[1,5- a ]quinoxalin-4(5 H )-ones through Photoredox-Catalyzed [3 + 2] Cyclization Reactions with Hypervalent Iodine(III) Reagents.

An efficient synthesis of a variety of [1,2,3]triazolo-[1,5- a ]quinoxalin-4(5 H )-ones via a [3 + 2] cyclization reaction by photoredox catalysis between quinoxalinones and hypervalent iodine(III) reagents is reported. A range of quinoxalinones and hypervalent iodine(III) reagents were tolerated well. This cyclization reaction allows access to structurally diverse [1,2,3]triazolo-[1,5- a ]quinoxalin-4(5 H )-ones in moderate to good yields.