Development of an Environmentally Friendly Anodic Fluorination System Based on Bipolar Electrochemistry

Electrochemical fluorination is one of the ideal methods for the selective fluorination of organic compounds under mild safe conditions. 1 Recently, Fuchigami and coworkers have demonstrated the electrochemical fluorination of organic compounds using alkali metal fluorides (MF) as a fluorine source and a supporting electrolyte in a poly(ethylene glycol) (PEG)/acetonitrile (MeCN) solution. 2 However, to drive electrochemical reactions, the use of a large amount of supporting electrolytes is still necessary. In this study, to reduce the amount of supporting electrolytes in electrochemical fluorination, we employed a split bipolar electrode (s-BPE) system, in which the redox reactions are driven in a low electrolyte concentration. 3 We optimized the electrochemical parameters for the s-BPE system using a U-shaped electrochemical cell and investigated the electrochemical fluorination of organic compounds such as triphenylmethane and derivatives in the presence of potassium fluoride (KF) or cesium fluoride (CsF) as a supporting electrolyte and a fluorine source in a PEG/MeCN solution. 4 References Fuchigami, T.; Inagi, S. Acc. Chem. Res. 2020 , 53 , 322. Sawamura, T.; Takahashi, K.; Inagi, S.; Fuchigami, T. Angew. Chem. Int. Ed. 2012 , 51 , 4413. Shida, N.; Zhou, Y.; Inagi, S. Acc. Chem. Res. 2019 , 52 , 2598. Miyamoto, K.; Nishiyama, H.; Tomita, I.; Inagi, S. ChemElectroChem 2019 , 6 , 97.