Promising Molecules for Optoelectronic Applications: Synthesis of 5,10‐Dihydrobenzo[ a ]indolo[2,3‐ c ]carbazoles by Scholl Reaction of 1,2‐Bis(indol‐2‐yl)benzenes

Only a few straightforward procedures for the preparation of indolo[2,3‐ c ]carbazoles are known, despite promising features for material applications. Herein we present a convenient synthesis of 5,10‐dihydrobenzo[ a ]indolo[2,3‐ c ]carbazoles using an oxidative cyclization of 1,2‐bis(1 H ‐indol‐2‐yl)benzenes prepared from readily accessible starting materials. Functionalization through electrophilic aromatic substitution reactions and palladium‐catalyzed cross‐coupling reactions were investigated, which lead to the isolation of new functionalized 5,10‐dihydrobenzo[ a ]indolo[2,3‐ c ]carbazoles, whose steady state electronic spectroscopy has been examined.