【摘要】 研究了钒化合物对N-羟基邻苯二甲酰亚胺(NHPI)催化分子氧氧化乙苯反应中的调变效应.结果表明,由8-羟基喹啉及其衍生物与乙酰丙酮氧钒(IV)配位制得的8-羟基喹啉氧钒(IV)配合物的催化活性比乙酰丙酮氧钒(IV),NH4VO3和V2O5的高.在优化的反应条件下,乙苯转化率和苯乙酮选择性可分别达60%～69%和97%.基于液体反应的紫外光谱,推测钒催化剂能够促进NHPI转变为N-氧基邻苯二甲酰亚胺自由基和1-苯基过氧化氢转变为苯乙酮.更多还原

【Abstract】 The mediation effect of vanadium compounds on the N-hydroxyphthalimide (NHPI)-catalyzed aerobic oxidation of ethylbenzene (EB) was investigated at 90 °C in benzonitrile. Among the vanadium mediators examined, a series of oxobis(8-quinolinolato) vanadium (IV) complexes (VIVOQ2), which were prepared by the coordination of 8-hydroxyquinoline or its derivatives with oxobis(2,4-pentanedionate) vanadium (IV) (VIV O(acac)2) showed a better mediation effect than VIVO(acac)2, NH4VO3, and V2O5 and they gave about 60%–69% EB conversion and 97% of acetophenone (AcPO) selectivity under optimum reaction conditions. This is due to the dual catalysis effects of these V mediators on the transformation of NHPI to the phthalimide-N-oxyl (PINO) radical and the decomposition of 1-phenylethyl hydroperoxide to AcPO, as supported by UV-Vis spectral characterization.更多还原