Superelectrophilic Csp3-H bond fluorination of aliphatic amines in superacid: the striking role of ammonium-carbenium dications.

The superacid-promoted electrophilic Csp3-H bond activation of aliphatic amines generates superelectrophilic species that can be subsequently fluorinated. Demonstrated by low-temperature in situ NMR experiments, the ammonium-carbenium dications, crucial for this reaction, can also react with C-H bonds opening future synthesis perspectives for this mode of activation.