【作者】 刘艳红；

【导师】 周林成；

【作者基本信息】 兰州大学 ， 高分子化学与物理， 2013， 硕士

【摘要】 磁性纳米颗粒及其复合材料在反应介质中具有有效分布的催化活性位点和磁性能,呈现出催化活性高、易回收、对环境污染小等特征。本文讨论了磁性Fe304纳米颗粒催化剂的设计与合成,并研究了磁性Fe3O4纳米颗粒固载含氮配体与CuI共催化在C-S键形成反应中的应用。此外,对磁性纳米颗粒固载的N-杂环卡宾催化的串联反应进行了研究。1.将γ-氨基丙基三乙氧基硅烷(APTS)、聚乙烯亚胺(PEI-600)作为含N配体来源,采取多种负载方式得到了5种氨基功能化的均一、单分散的磁性纳米复合材料CoFe204-NH2(Ligand A)、Fe3O4@Si(CH2)3NH2(Ligand B)、Fe3O4@Si(CH2)3PEI (Ligand C).Fe3O4@Si(CH2)3NHC(O)(CH2)2PEI (Ligand D)和Fe3O4@Si(CH2)3NHC(O)PEI (Ligand E),研究了其作为配体与CuI共催化芳杂环硫醇与芳香碘化物的C-S键偶联反应,实验结果表明反应具有广泛的底物适用性,产率高达99%。Ligand B和C在回收使用5次后仍具有良好的催化活性。2.首次制备了磁性Fe3O4纳米颗粒负载的N-杂环卡宾催化剂。通过8步反应得到氨基功能化的三唑卡宾前体5-(氨基甲基)-2-苯基-6,7-二氢-5H-吡咯[2,1-c][1,2,4]三唑四氟硼酸盐,用戊二醛交联至单分散Fe304纳米颗粒表面得到磁性纳米负载氮杂环卡宾催化剂,红外谱图和元素分析结果表明N-杂环卡宾负载成功,负载量0.6764mmol/g。将磁性纳米负载氮杂环卡宾催化剂应用于2-溴代肉桂醛和1,3-环己二酮的串联反应,实验结果表明催化剂失活,这可能与N-杂环卡宾作为配体与Fe3O4的铁原子发生配位有关。更多还原

【Abstract】 Superparamagnetic nanoparticles and composite materials, which possess high surface to volume ratios and have high surface energies, show a high catalytic activity and can be reused after separation from the reaction system by using a magnet. This paper discusses the design and synthesis of magnetic nanocatalyst, specifically about fabrication of magnetic nanocomposites for C-S bond coupling reaction and preliminary studies towards the preparation of magnetic nano-carbene catalyst.1. Aminosilane coupling agent and PEI-600as ligands were loaded to magnetic nano-particles, and uniformed monodisperse nanocomposites CoFe2O4-NH2(Ligand A), Fe3O4@Si(CH2)3NH2(Ligand B), Fe3O4@Si(CH2)3PEI (Ligand C), Fe3O4@Si(CH2)3NHC(O)(CH2)2PEI (Ligand D) and Fe3O4@Si(CH2)3NHC(O)PEI (Ligand E) were obtained. The catalytic applications of the synthesized magnetic nanocomposites were explored for the cross-coupling of heterocyclic thiols with aromatic iodides. The reaction was carried out in the presence of Cul (5mol%), ligand (10mol%N) and K2CO3(1.3eq) in DMF at120℃.A variety of heterocyclic sulfides were prepared in good to excellent yields (up to99%). Ligands B and C had a good catalyst activity after five consecutive cycles.2.5-(Aminomethyl)-2-phenyl-6,7-dihydro-5H-pyrrolo[2,1-c][1,2,4]triazol-2-ium tetrafluorobo-rate was synthesized through8steps. Triazole carbene precursor as a catalyst was crosslinked to Fe3O4nanomaterials by glutaraldehyde for the first time. Infrared spectra and elemental analysis showed that triazole carbene was successful imbolized on nanoparticles surface and the N-heterocyclic carbene loading amount reached0.6764mmol/g. The catalytic application of the synthesized magnetic nano-carbene catalyst was explored for the tandem reaction. The catalyst deactivated due to the interaction of N-heterocyclic carbene as ligand and iron atoms.更多还原