Radical C−N Borylation of Aromatic Amines Enabled by a Pyrylium Reagent

Herein, we report a radical borylation of aromatic amines through a homolytic C(sp(2))−N bond cleavage. This method capitalizes on a simple and mild activation via a pyrylium reagent ((Sc)Pyry‐OTf) thus priming the amino group for reactivity. The combination of terpyridine and a diboron reagent triggers a radical reaction which cleaves the C(sp(2))−N bond and forges a new C(sp(2))−B bond. The unique non‐planar structure of the pyridinium intermediate, provides the necessary driving force for the aryl radical formation. The method permits borylation of a wide variety of aromatic amines indistinctively of the electronic environment.