Convenient Access to α-Fluorinated Alkylammonium Salts

A series of novel α‐fluoroalkyl ammonium salts was obtained from the corresponding cyano compounds or nitriles by reaction with anhydrous HF. Room‐temperature stable trifluoromethyl ammonium salts were obtained in quantitative yield in a one‐step reaction at ambient temperature from the commercially available starting materials BrCN or ClCN. The novel cations [CF3CF2NH3]+, [HCF2CF2NH3]+, and [(NH3CF2)2]2+ were obtained from CF3CN, HCF2CN, and (CN)2, respectively, and anhydrous HF. The aforementioned fluorinated ammonium cations were isolated as room temperature stable [AsF6]− and/or [SbF6]− salts, and characterized by multi‐nuclear NMR and vibrational spectroscopy. The salts [HCF2NH3][AsF6] and [CF3NH3][Sb2F11] were characterized by their X‐ray crystal structure. Effing and binding: HF addition across the CN triple bonds of various nitriles and subsequent addition of MF5 (M=As, Sb) yields room‐temperature stable α‐fluoroalkyl ammonium salts. The cations [HCF2NH3]+, [CF3NH3]+, [CF3CF2NH3]+, [HCF2CF2NH3]+, and [(NH3CF2)2]2+ were prepared and isolated as [AsF6]−, [SbF6]−, and [Sb2F11]− salts.