N-Doped Cationic PAHs by Rh(III)-Catalyzed Double C–H Activation and Annulation of 2-Arylbenzimidazoles with Alkynes

Abstract

A novel class of N-doped cationic PAHs (Polycyclic Aromatic Hydrocarbons) bearing the benzo[c,d]fluoranthene scaffold has been synthesized by the Rh(III)-catalyzed double oxidative annulation of 2-arylbenzimidazoles with alkynes. The overall process involves a double C–N bond formation through a double C–H/N–H functionalization.The solid-state structures and electronic properties of the new N-doped PAHs were analyzed. These cationic azapolycycles were readily reduced in the presence of LiAlH4 or by the addition of PhLi to give interesting phenyl and diphenylmethanediamine derivatives.