Chemodivergent Synthesis of Indeno[1,2- b ]indoles and Isoindolo[2,1- a ]indoles via Mn(III)-Mediated or Electrochemical Intramolecular Radical Cross-Dehydrogenative Coupling.

Chemodivergent synthesis of indeno[1,2- b ]indoles and isoindolo[2,1- a ]indoles from the same starting materials involving radical cross-dehydrogenative couplings have been developed. Mn(OAc) 3 ·2H 2 O selectively promoted an intramolecular radical C-H/C-H dehydrogenative coupling reaction to provide indeno[1,2- b ]indoles, while an intramolecular radical C-H/N-H dehydrogenative coupling reaction could proceed via electrochemistry to deliver isoindolo[2,1- a ]indoles. Plausible mechanisms of the chemodivergent reactions were proposed.