Radical annulation of a designed diene system: access to nitro-benzo[ b ]azepines.

Herein, we describe a novel O 2 N˙-triggered ordered addition 7- endo cyclization reaction with excellent chemo- and regioselectivity. With such a strategy, structurally diverse nitro-benzo[ b ]azepines were prepared with 28 examples. Large-scale operation and handy N -Ts and N -Cbz deprotection reveal the promising utility of this methodology. Mechanistic studies suggest that the reaction proceeds through a radical pathway.