Photocatalytic [4 + 1] Annulation of Vinyl Aziridines with Alkyl Halides

Herein, we develop a photocatalytic [4 + 1] annulation of vinyl aziridines with alkyl halides. The reaction appears to experience radical trigger kinetically favored β-scission of the vinyl aziridine C-N bond, generating transient nitrogen-centered radical, followed by sequential single electron oxidation, 5-exo-trig cyclization, and protonation. Significantly, an unprecedented annulation mode in which vinyl aziridines serve as four-atom synthons has been disclosed.