Visible-light-mediated intramolecular radical cyclization of α-brominated amide-tethered alkylidenecyclopropanes.Chem Commun (Camb). 2022 Mar 15; 58(22):3653-3656.CC
A ring-opening/cyclization cascade reaction of α-brominated amide-tethered alkylidenecyclopropanes in the presence of photocatalyst 4CzIPN under visible-light irradiation was developed to afford polycyclic benzazepine derivatives in good yields with broad substrate scope and good functional tolerance. A plausible mechanism involving a halogen atom transfer (XAT) process and a radical chain process is proposed for this reaction. This study provides a concise and practical strategy for the synthesis of benzazepine derivatives.