Electrochemical dehydrogenative cyclization/aromatization of aniline-tethered alkylidenecyclopropanes: facile access to benzo[c]carbazoles

Abstract

A novel noble transition metal- and external oxidant-free electrochemical cyclization/aromatization of aniline-tethered alkylidenecyclopropanes enabled by N–H/C–H functionalization is described. Various highly functionalized benzo[c]carbazoles were constructed in atom-economical and sustainable manners, and exhibited a broad substrate scope and excellent regioselectivity. In addition, H₂ was the only theoretical byproduct in this protocol. Mechanistic studies indicated that the reaction proceeded through nitrogen-centered radical generation, cleavage of C–C bonds, C(sp²)–H functionalization and aromatization cascades.