Palladium-catalyzed carbonylation of quaternary ammonium halides to tertiary amides

• Published in: Applied organometallic chemistry 2014-04, Vol.28 (4), p.310-314
• Main Authors: Lei, Yizhu, Zhang, Rui, Wu, Linjuan, Wu, Qing, Mei, Hui, Li, Guangxing
• Format: Article
• Language: English
• Subjects: Amides; carbonylation; Carbonyls; Catalysis; Catalysts; ligand-free palladium; Palladium; quaternary ammonium halide; Quaternary ammonium halides; Quaternary ammonium salts; Recycled; tertiary amide
• ISSN: 0268-2605; 1099-0739
• DOI: 10.1002/aoc.3126

Catalytic carbonylation of quaternary ammonium salts under anhydrous conditions was investigated using palladium catalyst. The carbonylation of tetramethylammonium iodide was chosen as a model reaction and studied systematically. Ligand‐free PdCl2 showed efficient catalytic performance for this transformation. A palladium catalyst loading as low as 0.05 mol% was sufficient for high yield (96.9%) of N,N‐dimethylacetamide, corresponding to a turnover frequency of 242 h−1. Under optimum conditions, several other quaternary ammonium halides were also carbonylated to corresponding tertiary amides in moderate to excellent yields. The catalytic activity of commercial palladium on activated carbon (Pd/C) catalyst was also evaluated. The Pd/C catalyst exhibited high activity for this carbonylation reaction and could be recycled six times with a slight decrease in activity. Furthermore, mechanistic considerations concerning Pd‐catalyzed carbonylation of quaternary ammonium halides were also discussed. Copyright © 2014 John Wiley & Sons, Ltd. Catalytic carbonylation of quaternary ammonium salts under anhydrous condition was investigated by ligand free palladium catalyst. Moderate to excellent yields of tertiary amides was obtained with a relatively low catalyst dosage. The commercial Pd/C catalyst also showed high active for this carbonylation reaction and could be easily recovered and reused.