Pd-Catalyzed Intramolecular Aerobic Oxidative C–H Amination of 2‑Aryl-3-(arylamino)­quinazolinones: Synthesis of Fluorescent Indazolo­[3,2‑<i>b</i>]­quinazolinones

Abstract

A palladium-catalyzed intramolecular aerobic oxidative C–H amination of 2-aryl-3-(arylamino)­quinazolinones has been developed, providing a variety of substituted indazolo­[3,2-<i>b</i>]­quinazolinone derivatives in moderate to excellent yields. Preliminary mechanistic studies suggested that a palladacycle dimer could be the key intermediate, which underwent a cascade “rollover” cyclometalation and C–H amination sequence. Furthermore, the potential utility of these products has been demonstrated as a new class of blue fluorophores for fluorescent materials