Progress in transition‑metal‑ and photoredox‑catalyzed 3，3‑difluoro‑γ‑lactam synthesis

Introduction of a difluoroalkyl into small organic molecules would improve their bioactivity， which was prevalently used in drug design. In addition， γ-lactam， as one of the most important nitrogen-containing heterocyclic rings， was widely applied in synthetic and medicinal chemistry. Therefore， the development of synthetic strategies for 3，3-difluoro-γ-lactam was a valuable research topic. The methods of transition-metal- and photoredox-catalyzed 3，3-difluoro-γ-lactam synthesis were summarized， the mechanism and limitation of the reaction were discussed， and the future development direction was prospected.