TEMPO/固载化席夫碱铜配合物共催化剂在分子氧氧化苯甲醇过程中的催化性能

通过大分子反应,将苯甲醛(BA)和邻氨基苯酚(AP)形成的双齿席夫碱配基键合在交联聚甲基丙烯酸缩水甘油酯(CPGMA)微球表面,形成固载有席夫碱配基的载体微球BAAP-CPGMA,再通过与铜盐的配位螯合反应,制备了固载有席夫碱铜配合物的微球Cu(BAAP)2]-CPGMA.将该固载化铜配合物与均相的2,2,6,6-四甲基哌啶氮氧自由基(TEMPO)构成共催化体系TEMPO/Cu(BAAP)2]-CPGMA,应用于分子氧氧化苯甲醇的催化氧化过程.我们考察了该共催化体系的催化性能,并探索研究了催化氧化机理.实验结果表明,共催化体系TEMPO/Cu(BAAP)2]-CPGMA可在温和条件下(室温、常压的氧气)高效地将苯甲醇氧化为苯甲醛(选择性100%,苯甲醛产率93%),并具有良好的循环使用性能.

Catalytic Property of Co-catalyst of TEMPO/Immobilized Schiff base Copper Complex in Oxidation of Benzyl Alcohol by Molecular Oxygen

Bidentate Schiff base copper complex formed by benzaldehyde (BA) and ortho-aminophenol (AP) was bonded chemically on crosslinked poly(glycidyl methacrylate) microspheres CPGMA via macromolecular reactions, resulting in the supporter microspheres BAAP-CPGMA, on which Schiff base ligands were immobilized. And then through the coordionation reaction with copper salt, the immobilized- Schiff base copper complex microspheres Cu(BAAP)2]-CPGMA were obtained. A co-catalyst was constituted with the microspheres Cu(BAAP)2]-CPGMA and 2, 2, 6, 6- four methyl piperidine nitroxide (TEMPO) free radical, and it was used in the oxidation reaction of benzyl alcohol by molecular oxygen. The catalytic activity of this co-catalyst system was examined and the catalytic mechanism was researched. The experimental results show that the co-catalyst system consisting of the homogeneous main catalyst TEMPO and the heterogeneous sub-catalyst Cu(BAAP)2]-CPGMA can efficiently catalyzed the oxidation reaction of benzyl alcohol by molecular oxygen under mild conditions including at room temperature and at normal pressure for oxygen, and benzyl alcohol is transformed to benzaldehyde with 100% selectivity and with a yield of 93%. Furthermore, the co-catalyst has excellent cycle and reuse property.