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

Herein, we describe a novel O2N-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.

Automated summary

In this study, a novel O2N-triggered ordered addition 7-endo cyclization reaction is described, showing excellent chemo- and regioselectivity. With this strategy, structurally diverse nitro-benzo[b]azepines were successfully prepared, with a total of 28 examples. The large-scale operation and convenient N-Ts and N-Cbz deprotection demonstrate the promising utility of this methodology. Mechanistic studies suggest that the reaction proceeds through a radical pathway.