Angewandte Chemie International Edition2020 : Early View (2020).
The methylamino diazonium cations [CH3N(H)N2]+ and [CF3N(H)N2]+ were prepared as their low‐temperature stable [AsF6]‐ salts by protonation of azidomethane and azidotrifluoromethane in superacidic systems. They were characterized by NMR and Raman spectroscopy. Unequivocal proof of the protonation site was obtained by the crystal structures of both salts, confirming the formation of alkylamino diazonium ions. The Lewis acid‐base adducts CH3N3·AsF5 and CF3N3·AsF5 were also prepared and characterized by low‐temperature NMR and Raman spectroscopy, and, in case of CH3N3·AsF5, by X‐ray structure determination. Electronic structure calculations were performed to provide additional insights. Attempted electrophilic amination of aromatics such as benzene and toluene with methyl ‐and trifluoromethyl‐amino diazonium ions were unsuccessful.