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。
A series of L-histidine Schiff bases that include Sal-His（ H2L^1 ）, Br-Sal-His（ H2L^2 ）, NO2-Sal-His （H2L^3） 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 CuL^2 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.
出处
《应用化学》
CAS
CSCD
北大核心
2006年第7期718-723,共6页
Chinese Journal of Applied Chemistry
基金
国家自然科学基金资助项目(20436010)
作者简介
通讯联系人：唐瑞仁，男，1967年生，博士，副教授；E—mail：trr@mail．csu．edu．cn；研究方向：有机合成
