Synthesis of Heteroannulated Indolopyrazines through Domino N-H Palladium-Catalyzed/Metal-Free Oxidative C-H Bond Activation

ACS Omega. 2020 Jun 18;5(25):15681-15690. doi: 10.1021/acsomega.0c01945. eCollection 2020 Jun 30.

Abstract

A convenient approach to [1,2,5]oxadiazolo[3',4':5,6]pyrazino[2,3-b]indoles and their heteroannulated analogues bearing various aryl substituents in the backbone has been developed. This synthetic protocol is based on Pd-catalyzed Buchwald-Hartwig and subsequent annulation by intramolecular oxidative cyclodehydrogenation. The photophysical properties for new polycycles have been measured.