Rh(III)‐Catalyzed Oxidative Annulation of 2‐Arylquinoxalines with Cyclic 2‐Diazo‐1,3‐diketones by C−H Bond Activation

Abstract Rh(III)‐catalyzed C−H bond annulation of 2‐arylquinoxalines with cyclic 2‐diazo‐1,3‐diketones has been accomplished for the first time to synthesize a novel series of 2,3‐dihydrodibenzo[a,c]phenazin‐4(1 H )‐one frameworks by means of carbene insertion followed by condensation. The reaction proceeds through the C−H bond activation and functionalization of 2‐arylquinoxalines using Rh(III)/AgSbF 6 complex to produce highly substituted 2,3‐dihydrodibenzo[a,c]phenazin‐4(1 H )‐one and benzo[5,6][1,2,4]thiadiazino[2,3‐f]phenanthridin‐5(6 H )‐one‐10,10‐dioxide derivatives in good to excellent yields.