| Enlightened by the catalytic action of metal enzyme, people anchored the catalytically active components on the polymer containing some kind of ligands, thus prepared a new kind of catalyst called polymer metal complex catalyst. In general, polymer metal complex catalysts are more catalytically active, selective and stable compared to the corresponding low molecular weight ones, at the same time they can be easily recycled and have little causticity for equipments, hi some aspects, they simulated and showed some characters of metal enzyme. For these reasons, polymer metal complex catalysts have always been paid great attention by researchers on catalysis, so we first made a relatively detailed review of the recent advances in polymer metal complex catalysts in this thesis.According to the corresponding literatures, we first prepared MgO-supported melamine-formaldehyde polymer (abbr. as MEF / MgO), then acted it with palladium chloride to get the palladium complex of MgO-supported melamine-formaldehyde polymer catalyst (abbr. as Pd MEF / MgO). Then Pd MEF / MgO was characterized by IR, XRD and XPS, and the possible structure of the catalyst was given. Finally Pd MEF / MgO was successfully applied to the preparation of N-n-octyl-D-glucamine by catalytic hydrogenation and Heck arylation. The results were as following:1. The preparation and characterization of Pd MEF / MgO(1) During the preparation process of MEF / MgO, the mixture's pH(8.0-8.5), temperature (80 )and the occasion to add MgO are three key factors to adjust the polymerization degree and the content of ligands in the polymer.(2) The results of IR, XRD and XPS showed that melamine-formaldehyde polymer was not only adsorbed on MgO, but also changed the chemical structure of MgO, and Pd coordinated with N atoms in the polymer support. Pd particles were immobilized on the polymer and highly dispersed.(3) According to the characterization data, we gave the possible scheme of the preparation of Pd MEF / MgO catalyst.2. The application of Pd MEF / MgO catalyst in the preparation of N-n-octyl-D-glucamine by catalytic hydrogenation(1) The effects of additives, melamine/Pd mol ratio, Pd content and solvent on the reaction have all been studied. The results are as following: The addition of triethylamine greatly improves the catalyst's activity, so the best additive is triethylamine. No evident maximal yield is gotten with the change of the melamine/Pd mol ratio in the catalyst. The optimum Pd content in the catalyst is 3.55%(w/w). The best reaction solvent for this reaction is ethanol.(2) The reaction conditions are optimized through the orthogonal experiment and elasticity experiment, and the optimum reaction conditions are as follows: the amount of catalyst, 0.7 g(N%=5.58%, Pd%=3.55%); D-glucose : octylamin =1.2:1(mol : mol); additive, 1.0ml triethylamine; reaction temperature, 60℃ ; hydrogen pressure, 1.5MPa. Under these experimental conditions, the highest yield of N-n-octyl-D-glucamine (57.6%) is obtained.(3) The composition and structure of the product N-n-octyl-D-glucamine were characterized by elemental analysis, IR, 1HNMR and 13CNMR spectra.(4) After two cycles, the activity of Pd MEF/MgO began to reduce. After reflux distillation in ethanol, the catalyst's activity recovered, but can't reach the original level.3. The application of Pd MEF/MgO catalyst in the Heck arylation of iodobenzene with acrylic acid(1) Under different reduction conditions, we prepared four different Pd ?MEF/MgO catalysts and used them in the Heck reaction. We found the catalyst reduced in the ethanol had the highest catalytic activity.(2) For its good solubility and proper basicity, triethylamine is the best base in this reaction.(3) The effects of solvent, mole ratio of iodobenzene with acrylic acid, reaction temperature, the amount of base and the catalyst on the Heck arylation have all been studied. The best reaction condition was that under 80℃, 15mmol acrylic acid, 10mmol iodobenzene, 47mmol... |
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