Quaternary ammonium salts are widely used as surfactants, 1 phase-transfer catalysts, 2 templates, 3,4 molecular probes, and ionic channel blockers. 5 Considerable efforts have already been devoted to studies in the synthesis, structure, and thermal stability of these compounds. Quaternary ammonium salts were conventionally synthesized by reacting amines or amides with alkyl halides. Wang et al. 6,7 reported a facile method to synthesize ...