Amidinyl Radical Formation through Anodic N-H Bond Cleavage and Its Application in Aromatic C-H Bond Functionalization

Abstract

We report herein an atom-economical and sustainable approach to access amidinyl radical intermediates through the anodic cleavage of N-H bonds. The resulting nitrogen-centered radicals undergo cyclizations with (hetero)arenes, followed by rearomatization, to afford functionalized tetracyclic benzimidazoles in a highly straightforward and efficient manner. This metal- and reagent-free C-H/N-H cross-coupling reaction exhibits a broad substrate scope and proceeds with high chemoselectivity.

Keywords: benzimidazoles; cyclization; electrochemistry; heterocycles; radicals.