Development of a Split Bipolar Electrode System for Electrochemical Fluorination of Triphenylmethane

To overcome the problem of electrochemical fluorination methods using a large amount of supporting electrolytes and fluorine sources, we employed a split bipolar electrode (s-BPE) system, in which electrode reactions occur in a low concentration of supporting electrolyte and electricity is monitored. We optimized the electrochemical parameters for the s-BPE system using a U-shaped electrochemical cell and investigated the electrochemical fluorination of triphenylmethane as a model substrate in the presence of potassium fluoride (KF) or cesium fluoride (CsF) as a supporting electrolyte and a fluorine source dissolved by the help of poly(ethylene glycol) (PEG) additive. The fluorination of triphenylphoshine was also examined under the optimized conditions.