Iron- or Copper-Catalyzed Trifluoromethylation of Acrylamide-Tethered Alkylidenecyclopropanes: Facile Synthesis of CF₃-Containing Polycyclic Benzazepine Derivatives

A novel iron- or copper-catalyzed trifluoromethylation of acrylamide-tethered alkylidenecyclopropanes with Togni reagent II to construct CF3-containing tetracyclic benzazepine derivatives under mild and convenient conditions has been disclosed. The chemoselective addition of in situ generated trifluoromethyl radical onto the activated alkenes triggers the reaction followed by a ring-opening process of alkylidenecyclopropanes, leading to the formation of two types of CF3-containing tetracyclic benzazepine derivatives in moderate to good yields, respectively, with excellent functional group tolerance.