fluorinate

Fluorinate is the process of introducing fluorine atoms into a molecule, creating carbon–fluorine or other C–F bonds. In practice, fluorination is achieved by electrophilic fluorination (adding F+), nucleophilic fluorination (adding F−), or radical fluorination, each with distinct reagents and substrate scope. Direct fluorination with elemental fluorine is powerful but hazardous and used mainly in specialized settings for small or simple substrates.

Common deoxyfluorination reagents such as DAST (diethylaminosulfur trifluoride) and Deoxo-Fluor convert alcohols into alkyl fluorides, and related reagents enable installation of fluorine at other functional groups. Electrophilic fluorination uses reagents like Selectfluor and N-fluorobenzenesulfonimide (NFSI), often with catalysts, to introduce fluorine into electron-rich arenes, alkenes, or heterocycles. Nucleophilic fluorination uses fluoride sources (CsF, KF, tetra-n-butylammonium fluoride) for SN2 substitutions or as [18F]fluoride in radiolabeling for PET imaging.

Applications include pharmaceuticals and agrochemicals, where fluorination can improve metabolic stability, lipophilicity, and bioavailability; in radiochemistry, fluorine-18 labeling enables PET imaging; and in materials science, fluorinated motifs impart thermal and chemical resistance.

Safety: fluorine gas is highly reactive and corrosive; many fluorinating reagents are toxic or reactive with moisture or acids, requiring good ventilation, appropriate personal protective equipment, and careful waste management.