Synthesis of acridones through the ring expansion of isatins with arynes oxidated by O2 in air

A simple and environmental-friendly method for the construction of acridone derivatives with isatins and arynes was described. The isatins underwent a ring expansion process oxidized by O2 in the air and a broad scope of acridones in moderate to good yields were obtained. Baeyer-Villiger-type oxidation and intermolecular-nucleophilic addition were included, and no extra oxidant except O2 was needed.(c) 2022 Elsevier Ltd. All rights reserved.