Radical fluorination is a type of fluorination reaction, complementary to nucleophilic and electrophilic approaches. HF is a reactive solvent in the electrochemical fluorination of organic compounds. These can be easily synthesized by alkylation followed by fluorination. The mechanism of electrophilic fluorination remains controversial. Examples of radical fluorination using BrF and fluorinated solvents have been reported. A specialized but important method of electrophilic fluorination involves electrosynthesis. The use of fluorine for radical fluorination is mainly limited to perfluorination reactions. It is prepared by the electrochemical fluorination of sulfolane. Another method of synthesizing cyanogen fluoride is by the fluorination of cyanogen. PFOA has two main synthesis routes, electrochemical fluorination (ECF) and telomerization. Silicon tetrafluoride has been found to act as a catalyst in fluorination by . In 1947, 3M began producing perfluorooctanoic acid (PFOA) by electrochemical fluorination. In 1949, 3M began producing POSF by electrochemical fluorination (ECF). Diols can undergo pinacol rearrangement under fluorination conditions. Perchloryl fluoride is produced primarily by the fluorination of perchlorates.