Enabling Access to 3‐gem‐Difluorovinyl Lactams via Zn‐Mediated Sequential Single Electron Reductive Hydrodehalogenation.

Comprehensive Summary: Herein, we describe a direct route for the synthesis of 3‐gem‐difluorovinyl lactams through Zn‐mediated reductive hydrodehalogenation. Importantly, by using inexpensive deuterium oxide (D2O), the high value‐added vicinal dideuterated gem‐difluoroalkenes with excellent deuterium (D) incorporation were prepared. Mechanism studies indicated a successive single electron transfer process: the reaction initially undergoes hydrodechlorination to give the intermediate α‐trifluoromethylidene lactams, which are then activated by the in‐situ generated zinc cations and reduced to the desired product via hydrodefluorination. [ABSTRACT FROM AUTHOR]