【作者】 高俊阳；

【导师】 胡兴邦；

【作者基本信息】 南京大学 ， 化学工程， 2012， 硕士

【摘要】 异佛尔酮本身是优良的高分子溶剂以及化工中间体,其选择性氧化产物氧代异佛尔酮则是多种类胡萝卜素以及调味化合物的关键中间体。但是,自从氧代异佛尔酮工业化生产以来,几乎所有关键技术和生产都被国外所垄断。随着我国本土精细化工的发展,氧代异佛尔酮需求量越来越大,亟待自主生产并降低成本。所以,研究选择性氧化异佛尔酮直接合成氧代异佛尔酮是非常有意义的。但由于异佛尔酮C=O双键与C=C双键间存在共轭,电子离域的作用使得烯丙位的C-H键键能增强,使得异佛尔酮难以直接氧化。若能找到一种简单的方法来削弱C=O双键与C=C双键间的电子离域作用,将能有效降低C-H键键能,起到C-H活化的效果,从而使得本身难以直接氧化的异佛尔酮变得容易氧化。本文研究的目的就是探寻这样一种能削弱电子离域,从而使底物得以活化的非催化剂修饰方法。本文的工作内容主要是在前人研究的基础上,以共沉淀法制备含Cu、Mg、Al三种金属的类水滑石催化剂,尝试以路易斯酸盐作为添加剂,通过添加剂与底物之间的相互作用而达到C-H活化的效果,从而提高直接氧化异佛尔酮反应的效率,得到的结论如下：(1)制备的催化剂为NO3-离子插层型的类水滑石六方晶系且有一定含量的结合水,催化剂中三种金属的物质的量之比与投料比接近,Cu:Mg:A1≈1:3:1,并综合热重和元素分析得到了每种金属在催化剂中的质量摩尔浓度。(2)通过加入各种不同的路易斯酸作为添加剂,在目标产物产率基本不受影响的情况下,确实大大缩短了直接氧化异佛尔酮这一反应的时间,从48h缩短到4h左右。其中,以加入典型的路易斯酸盐ZnCl2, AICl3, SnCl2等作为添加剂的效果最好。(3)通过一系列反应条件控制和比较,得到了使目标产物KIP转化率最大的条件a以及使整个催化反应效率最高的条件b,分别为a.60℃,催化剂量为0.1g, ZnCl2为20%异佛尔酮摩尔量,TBHP为3.5倍异佛尔酮摩尔量b.60℃,催化剂用量为0025g, ZnCl2为20%异佛尔酮摩尔量,TBHP为2.5倍异佛尔酮摩尔量反应时间均为4h,a目标产物产率可达53.6%(选择性100%),TOF=4.4／h,b目标产物产率可达43.0%(选择性100%),TOF=141.0/h。(4)提出了添加剂与底物作用的机理并以计算佐证,同时以1H-NMR和紫外吸收光谱通过实验证实这一作用的存在。总之,本文提出的这一提高催化反应效率的方法是切实可行且有新颖性,这也为研究催化反应提供了一个新的思路。更多还原

【Abstract】 Isophorone is a great solvent of polymer compound and an important intermediate of chemical industry, and its selective oxidation product ketoisophorone, is the key intermediate for the synthesis of various carotenoids and flavoring substances. But since the isophorone has been industrial produced, almost all the key technologies and most of volume of production have been kept from us. Along with the development of native fine chemical industry, the demand of native produced isophorone and cost reduction kept growing. It is meaningful for us to do research about the direct oxidation from isophorone to ketoisophorone.The reason that isophorone is hard to be directly oxidized, because there is conjugation effect between C=O and C=C which enhances the C-H bond of allylic position. If we find an easy way to weaken the electronic delocalization effect between C=O and C=C, the C-H bond dissociation energy will be decreased efficiently. C-H activation makes isophorone easy to be oxidized. What we want to present here is a method without catalyst modified to weaken the delocalization effect and activate the substrate.The main work of this thesis is based on the predecessors, we use coprecipitation to synthetize HTLcs with Cu, Mg and Al. We make Lewis acid as our additives here, it weakens the electronic delocalization effect of isophorone and makes the C-H bond of allylic position activated. Eventually we improve the efficiency of isophorone oxidation. Here are the main conclusions:(1) The synthetized catalyst is NO3-intercalated HTLc with hexagonal system and some amount of H2O. The ratio of the amount of substance of three metal elements in the catalyst is close to their raw ratio, Cu:Mg:A1≈1:3:1. We calculate the molality of each metal element with results of TGA and ICP.(2) By adding different kinds of Lewis acids as additives, the reaction time of isophorone oxidation is shortened from48h to4h without the decrease of the target product yield. Among all kinds of additives, ZnCl2, AICl3and SnCl2 are more efficient.(3) Through a series of researches, we get two optimized conditions. A has the maximum yield of the target product KIP and b has the maximum catalytic reaction efficiency. a.60℃,0.1g HTLc,20%molar weight of isophrone ZnCl2,350%molar weight of isophrone TBHP b.60℃,0.025g HTLc,20%molar weight of isophrone ZnCl2,250%molar weight of isophrone TBHP The reaction time is4h. Under condition a, yield of target product KIP is53.6%(100%selectivity), TOF=4.4/h, and under condition b, yield of KIP is43.0%(100%selectivity), TOF=141.0/h.(4) A computational simulation confirms that the lewis acid does make the substrate more active.1HNMR and ultra violet absorption spectroscopy gave evidence on the existence of interaction between the additive and isophorone.In brief, the presented way to improve the catalytic reaction efficiency is achievable and novel. It gives us a new thinking of studying catalytic reactions.更多还原