- 4-N,N-Dimethylaminopyridine promoted selective oxidation of methyl aromatics with molecular oxygen.
4-N,N-Dimethylaminopyridine promoted selective oxidation of methyl aromatics with molecular oxygen.
Molecules (Basel, Switzerland) (2012-04-03)
Zhan Zhang, Jin Gao, Feng Wang, Jie Xu
PMID22466855
RESUMEN
4-N,N-Dimethylaminopyridine (DMAP) as catalyst in combination with benzyl bromide was developed for the selective oxidation of methyl aromatics. DMAP exhibited higher catalytic activity than other pyridine analogues, such as 4-carboxypyridine, 4-cyanopyridine and pyridine. The sp3 hybrid carbon-hydrogen (C-H) bonds of different methyl aromatics were successfully oxygenated with molecular oxygen. The real catalyst is due to the formation of a pyridine onium salt from the bromide and DMAP. The onium salt was well characterized by NMR and the reaction mechanism was discussed.