Photo-Induced Synthesis of Functionalized -Lactams via Iron-Catalyzed LMCT Cascade

A base-and-additive-free photo-induced radical-mediated cascade cyclization reaction of 1,6-enyne compounds was presented. In this study, C(sp3)-H hydrocarbons, including various alkanes and ethers, were activated via Fe-catalyzed photo-induced conditions, providing a bunch of gamma-lactam products via hydrogen atom transfer and radical addition processes. Control experiments indicated that the reaction proceeded through photo-induced ligand-to-metal charge transfer (LMCT) process. Gram scale experiment was also completed by using continuous-flow-photocatalytic-device.