Divergent Conversion of <i>N</i>‑Acyl-isoxazol-5(2<i>H</i>)‑ones to Oxazoles and 1,3-Oxazin-6-ones Using Photoredox Catalysis

The fragmentation of N-acyl-isoxazol-5-ones using visible light photoredox catalysis has been disclosed. The catalyst-controlled divergent mechanisms, namely the oxidative and reductive quenching catalytic cycle, are utilized. Various oxazoles and 1,3-oxazin-6-ones are selectively obtained from the same isoxazol-5-one skeleton under mild conditions