Transition-Metal-Free Approach to Acridone Derivatives by TBHP-Promoted Oxidative Annulation of Isatins with Arynes.

A tert -butyl hydroperoxide-promoted oxidative annulation reaction of isatins with 2-(trimethylsilyl)aryl triflates for the convenient synthesis of acridone derivatives has been established. Mechanistic investigation suggested that the reaction may proceed via consecutive Baeyer-Villiger-type rearrangement followed by an intermolecular cyclization. This synthetic approach offers several advantages, including broad substrate scope, good functional group tolerance, and simplicity of operation. Additionally, successful late-stage modification of the obtained compounds was achieved, expanding the application potential of this methodology in organic synthesis.