【作者】 彭丽芬；

【导师】 许新华；

【作者基本信息】 湖南大学 ， 有机化学， 2011， 硕士

【摘要】 近年来,许多文献报道了茂金属的全氟甲基磺酸盐配合物Cp₂M （OTf）₂ （Cp = C₅H₅; M = Ti, Zr, OTf= OSO₂CF₃）能有效地催化许多碳-碳键形成的反应。但是这些配合物对空气不稳定。2009年,本实验室课题组设计合成了对水和空气都稳定的化合物二（全氟辛基磺酸）二茂锆,并且其在糖基化反应以及羧酸与酸酐的酰化反应中表现出很好的Lewis酸催化活性。羧酸与醇的直接酯化反应和羧酸酯与醇的酯交换反应是制备化学及药物中间体的重要反应。然而,这些反应都是平衡反应,为了使平衡向产物方向移动,必须使一种反应物过量或蒸馏出反应产生的产物。传统的硫酸催化的酯化反应具有毒性、腐蚀性、污染环境和产率低等不足。因此,本论文选择二（全氟辛基磺酸）二茂锆（Cp₂ Zr （OSO3C8F17）₂）作催化剂,并研究了在无溶剂条件下,其催化的羧酸与醇的直接酯化、羧酸酯与醇的酯交换反应以及应用于生物柴油的制备。研究表明:在无溶剂条件下,催化量的二（全氟辛基磺酸）二茂锆就能有效地催化羧酸与等当量的醇的直接酯化反应。脂肪酸与芳香醇酯化反应的产率达95%以上,芳香羧酸与脂肪醇酯化反应产率一般达90%以上,长链脂肪酸酯的产率也很高,达到85%。并且催化剂可以重复使用,循环使用4次后,催化剂的活性只有少量的下降。且发现有水存在下（水量达200 mol%）,对酯化反应没有影响。本反应具有无溶剂、无副反应、绿色环保、催化剂可以重复使用、反应物比例为1:1等特点,符合绿色化学的要求。无溶剂条件下,催化量的二（全氟辛基磺酸）二茂锆也能有效地催化羧酸酯与等当量的醇的酯交换反应。芳香醇与羧酸酯的酯交换反应的产率一般达到90%以上,脂肪醇的反应活性略低于芳香醇。催化剂对C-Br和C=C没有影响。该反应具有反应条件温和、产率高、无溶剂、操作简单等优点。生物柴油的生产方法主要是催化剂作用下的动植物油与低分子醇的酯交换反应。本论文研究了在二（全氟辛基磺酸）二茂锆催化下,运用茶油与甲醇或乙醇的酯交换反应来制备生物柴油。研究表明:茶油与醇的摩尔比、催化剂的用量以及温度对反应有很大的影响。在温度是醇的沸点、压强为大气压、催化剂的用量是6 mol% （相对于茶油）和醇做溶剂的条件下,脂肪酸酯的产率最高（达到90%以上）。且催化剂可以通过沉淀和用石油醚洗涤来回收,循环使用10次以上,催化活性只有少量的下降。更多还原

【Abstract】 Presently, many documents have shown that the metallocene bis （triflate） s complexes of titanium and zirconium Cp₂M （OTf）₂ （Cp = C₅H₅; M = Ti, Zr, OTf= OSO₂CF₃） can efficiently accelerated various carbon–carbon bond forming reactions. But the complexes are air-sensitive. In 2009, our research group has synthetized air and water stable zirconocene bis（perfluorooctanesulfonate）s Cp₂Zr（OPf）₂(OPf=OSO₂C₈F₁₇), which has shown high Lewis acidity in glycation and acylation of carboxylic acids and alcohols.Direct esterification between carboxylic acids and alcohols and transesterification of carboxylic ether and alcohols are fundamental transformations in preparation of chemical and pharmaceutical important intermediates. However, these reactions are equilibria. We should excessively use one reactant or remove the product to bias the equilibrium to the benefit of the product side. There are some disadvantages such as toxicity, causticity, environmental unfriendly and low yield in traditional esterification catalyzed by sulfuric acid.So we studied the esterification between carboxylic acids and alcohols, transesterification between carboxylic ether and alcohols, and it’s application in biodiesel synthesis, using zirconocene bis（perfluorooctanesulfonate）s Cp₂Zr（OPf）₂ as a catalyst under solvent-free condition.Catalytic amount of zirconocene bis（perfluorooctanesulfonate）s can efficiently promote esterification of carboxylic acids with equimolar amounts alcohols under solvent-free condition. The yield of the reaction of fatty acids with aromatic alcohols is more than 95%, compared to 90% of the reaction of aromatic acids with fatty alcohols. And the yield of long chain fatty acids esters is 85%. The catalyst can be reused 4 times with little loss of activity. What’s more, our study shows that water （≤200 mol%） has no effect to the esterification. This reaction, under solvent-free, having no side reactions, being environment-friendly and reusable catalyst, agrees with demand of Green Chemistry.Catalytic amount of zirconocene bis（perfluorooctanesulfonate）s can efficiently promote transesterification of carboxylic ether with equimolar amounts alcohols under solvent-free condition. Generally, the yields of the reaction of carboxylic ether with alcohols are more than 90%. The reactive acidity of fatty alcohols is a little lower than aromatic alcohols. And the catalyst make no difference to the C-Br and C=C bond. This reaction has many advantages such as mild reaction condition, high yield, solvent-free, simplicity of operator and so on.The main synthetic approaches have been used for biodiesel production that is transesterfication of Vegetable oils or animal fats with a low molecular weight alcohol using a catalyst. In our study, we make biodiesel by transesterification of teaseed oil with methanol or ethanol using zirconocene bis（perfluorooctanesulfonate）s as a catalyst. The effect on reaction is the mole ratio of teaseed oil and alcohol, the amount of catalyst, and temperature. When the reaction temperature is the alcohol’s boiling temperature, the pressure is atmospheric pressure, the amount of catalyst is 6 mol% （relative to vegetable oil）, and methanol or ethanol is solvent, the yield is the highest （more than 90%）. Significatively, the catalyst can be purified by precipitate and washed by petroleum ether, and can be reused more than 10 times with little loss of activity.更多还原