Catalyst‐Free Defluoroalkylation of Trifluoromethylated Alkenes via Photoinduced Electron Donor‐Acceptor Complex.

Radicals can be formed expeditiously through the direct irradiation of an electron donor‐acceptor (EDA) complex. Herein, we show a photocatalyst‐free strategy for gem‐difluoroalkenes synthesis realized by photo‐irradiation of the EDA complexes, which can be generated in situ between N‐alkylpyridinium salts and Hantzsch ester without any other additives. A wide variety of readily available alkylamines underwent deaminative defluoroalkylation to provide the corresponding gem‐difluoroalkenes. This reaction system exhibits high reactivity and good functional group tolerance and provides a practical and effective entry to a broad range of α‐alkyl‐substituted gem‐difluoroalkenes. [ABSTRACT FROM AUTHOR]