Chemistry of N-fluoropyridinium salts
This tutorial review deals with developments in the chemistry of N-fluoropyridinium salts in the past decade, including both synthetic and mechanistic aspects. Three distinct types of transformations including: i) fluorination reactions, ii) carbenoid behavior and iii) cine-/tele- substitution involving N-fluoropyridinium cation are exemplified. Procedures for fluorination of carbanions and benzenoid aromatics along with hetarylation processes yielding 2- and 4-substituted pyridines are referenced. Several new discoveries in the area, including three-component condensation reactions of in situ generated N-fluoropyridinium fluoride are described.