Electrophilic fluorinating agents containing N-F bonds

It is frequently overlooked that, following fluorination, some of these systems, e.g. Selectfluor , are extremely acidic and may, consequently, ionise the carbon-fluorine bond just formed, leading to a carbocation and subsequent reaction with the solvent (see Section IIIA) [65]. 

These fluorinations are generally considered to proceed by nucleophilic attack on fluorine, rather than via an electron-transfer mechanism [115], as determined from radical 

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