Facile synthesis of indolo[3,2- a]carbazoles via Pd-catalyzed twofold oxidative cyclization

Beilstein J Org Chem. 2016 Nov 22:12:2490-2494. doi: 10.3762/bjoc.12.243. eCollection 2016.

Abstract

A rapid and efficient route has been developed for the synthesis of 9-methoxycarbonylindolo[3,2-a]carbazole derivatives. The key steps in this approach involved an aromatic amination and an oxidative biaryl coupling. Via the present route, indolo[3,2-a]carbazole derivatives are available in 3-4 steps based on commercially available starting materials.

Keywords: N-arylation; cyclization; indolo[3,2-a]carbazole; oxidative biaryl coupling; palladium catalysis.