Visible-Light-Induced [5 + 1] Annulation of Vinyl Cyclopropane with Nitrene

A metal- and reagent-free visible-light-mediated [5 + 1] annulation of vinyl cyclopropanes with iminoiodinanes has been developed, providing efficient access to 1,2,3,6-tetrahydropyridines with broad substrate tolerance for aryl, alkyl, and heteroaryl substituents. These scaffolds undergo base-promoted aromatization to 2,5-diarylpyridines and diverse transformations, highlighting their utility in medicinal and materials chemistry. Mechanistic studies reveal a triplet nitrene-initiated radical pathway involving selective cyclopropane ring opening, advancing sustainable C-N bond formation.