【摘要】 合成了芳环上含不同取代基的Sch iff碱配体(水杨醛缩组氨酸(H2L1)、5-溴水杨醛缩组氨酸(H2L2)、5-硝基水杨醛缩组氨酸(H2L3))及其铜(Ⅱ)配合物,研究了其作为催化剂应用于催化分子氧氧化β-紫罗兰酮制备4-氧代-β-紫罗兰酮中的行为。提出了可能的催化反应机理。结果表明,取代基影响铜(Ⅱ)配合物的催化性能,其催化效果为CuL2>CuL1>CuL3,吡啶可增强其催化活性。以CuL2作催化剂,当反应时间为10 h、反应温度为75℃、催化剂用量为1.6%(摩尔分数)、O2气压力为1 MPa、添加摩尔分数为30%吡啶时,4-氧代-β-紫罗兰酮的收率为50.2%,纯度超过98.5%。氧化产物、Sch iff碱配体及其铜(Ⅱ)配合物的结构经EA、IR、1H NMR和MS等测试方法表征。未反应的原料经减压蒸馏回收利用,催化剂经过滤分离、活化,其重复使用性良好。更多还原

【Abstract】 A series of L-histidine Schiff bases that include Sal-His(H₂L¹),Br-Sal-His(H₂L²),NO₂-Sal-His(H₂L³) and their Cu（Ⅱ） complexes were synthesized,and the catalytic behavior of Schiff-base-Cu for the oxidation of β-ionone to 4-oxo-β-ionone as well as the effects of substitutents on these properties were（examined）.The effects of reaction temperature,reaction time,molar ratio of catalyst to β-ionone, the amount of pyridine additive and O₂ pressure on the catalytic activity of the various catalysts were optimized and a（probable） catalytic mechanism was proposed.The results showed that the catalytic performances of Schiff-base-Cu（Ⅱ） complexes were affected by substituted groups and enhanced by additive pyridine.The main product was 4-oxo-β-（ionone） with a yield of 50.2% and a purity over 98.5% under O₂ pressure（1 MPa） at 75 ℃ with additive pyridine over catalyst CuL² in 10 h.The structures of L-histidine Schiff bases,their Cu（Ⅱ）（complexes） and oxidation product were characterized by IR,MS,¹H NMR and EA.The excessive β-ionone and the catalysts can be reused via vacuum distillation and filtration.更多还原