Direct Synthesis of 2-Aryl-4-quinolones via Transition-Metal-Free Intramolecular Oxidative C(sp3)–H/C(sp3)–H Coupling

A novel, metal-free oxidative intramolecular Mannich reaction was developed between secondary amines and unmodified ketones, affording a simple and direct access to a broad range of 2-arylquinolin-4(1H)-ones through C(sp3)–H activation/C(sp3)–C(sp3) bond formation from readily available N-arylmethyl-2-aminophenylketones, using TEMPO as the oxidant and KOtBu as the base.