Synthesis of [1,2,3]Triazolo-[1,5‑a]quinoxalin-4(5H)‑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(5H)-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(5H)-ones in moderate to good yields.