【作者】 高瑞华；

【导师】 戴维林；

【作者基本信息】 复旦大学 ， 物理化学， 2009， 博士

【摘要】 众所周知,烯烃氧化反应是有机合成中最重要最基本的化学反应之一。但这一类反应往往需要使用有毒有害的有机溶剂（如卤代烃类）和导致酸污染的氧化剂（如过氧酸类）,不符合现在大力提倡的“绿色化学”的发展方向。从减少污染、保护环境的绿色化学角度出发,近几年国内外开发了不少新型氧化方法,研究开发了许多污染少、能耗小、环境相容性好的氧源,如过氧化氢、分子氧等,这些可能是极具应用前景的烯烃氧化方法。过氧化氢是一种较为理想的环境友好氧源,反应后生成对环境无害的水,而且“活性氧”的含量高。在双氧水-氧化体系中,过渡金属（如钨、锰、钼和铑）化合物都是非常有效的催化剂,其中钨基催化剂表现出了很高的双氧水利用率和目标产物选择性。钨基催化剂对双氧水的分解无催化作用,并且相对于其他过渡金属化合物而言,钨化合物便宜易得。因此,钨基催化剂的研究是研究人员广泛关注的热点。含氧杂环化合物（9-氧-双环[3.3.1]-2,6壬二醇（1）和2-羟基-9-氧-双环[3.3.1]-6-壬酮（2））是非常重要的化工中间体,它可以合成多种内酯化合物,而内酯化合物是合成生物活性药物的重要前体。例如,5-羟基-γ-十内酯是一种潜在的肿瘤细胞抑制剂。因此,合成氧杂环化合物对于医药领域具有非常重要的意义。文献调研表明,在氧杂环化合物的合成过程中普遍存在酸污染、难分离等缺点。为此,本论文旨在开发一条合成氧杂环化合物的新路线,并寻找高活性、高稳定性、可多次回收利用的新型含钨纳米催化剂,为氧杂环化合物的工业化生产提供理论基础。论文的主要工作及结果如下:1.钨酸或磷钨酸催化1,5-环辛二烯选择氧化制备氧杂环化合物的绿色路线实现了以1,5-环辛二烯为原料,H₂O₂为氧化剂,在催化剂钨酸或磷钨酸的作用下一步合成氧杂环化合物的绿色合成路线。a.以钨酸为催化剂时,双氧水与COD的摩尔比例越高,COD的转化率和1+2的选择性越高,但是考虑到成本我们选取3:1为最佳比例;催化剂的用量不仅影响COD的转化率和目标产物（1+2）的选择性,也影响化合物1和2的分布;溶剂的影响也很大,对于醇类,支链越多,（1+2）的选择性越好,非质子性溶剂也有很好的选择性。COD与溶剂的体积比越大,催化剂的活性越高。b.HPW相比钒钼杂多酸催化剂,无论从活性还是选择性的角度都具有明显的优势,HPW是COD选择氧化的优良催化剂。以磷钨酸为催化剂时,双氧水与COD的摩尔比例越高,COD的转化率和（1+2）的选择性越高;催化剂的用量越大,COD的转化率越高;溶剂的影响也很大,叔丁醇是一个很好的溶剂;叔丁醇与COD的体积比对反应也有很大影响,叔丁醇与COD的体积比小于10时,活性和选择性都好;反应温度越高,催化剂的催化性能也越好,但是双氧水更容易分解,因此选择60℃为最佳反应温度。整个催化过程不采用任何相转移催化剂和有毒溶剂,只以H₂O₂为氧源,产物为水,清洁无毒害,符合绿色环保的要求。并且目标产物的总得率很高,具有工业化前景。2.含钨介孔泡沫材料的原位合成及其在1,5-环辛二烯选择氧化反应中的性能研究对于上述催化氧化1,5-环辛二烯制氧杂环化合物的绿色路线,以钨酸或磷钨酸为均相催化剂的方法虽然（1+2）总得率很高,但是均相催化存在催化剂难以回收再利用的缺点。于是我们采用原位合成方法制备了WO₃-MCF介孔泡沫分子筛催化剂。将此催化剂应用于上述反应,也取得了很好的结果。为了便于比较,我们也利用浸渍法合成了WO₃/MCF催化剂。TEM、XRD、Raman和UV-Vis。DRS表征结果说明,当氧化钨含量小于20%时,钨物种高度分散在MCF中,大部分钨物种能有效进入MCF的骨架,其它则以孤立的或低聚态的钨物种形式分布于催化剂中。另外,研究发现钨物种主要以无定形的形式存在,这样富含催化氧化活性中心的无定形钨物种提高了对1,5-环辛二烯的催化氧化性能。并且原位合成的催化剂上三氧化钨的分散性能要强于普通浸渍法制备的催化剂。XRD和TPR表征表明,原位合成方法中,钨物种与二氧化硅基体之间的相互作用较强,能有效阻止钨物种的脱落,并有效降低钨物种在催化剂表面的聚集程度。而普通浸渍法中,钨物种在催化剂表面聚集明显。WO₃-MCF介孔分子筛催化剂具有良好的1,5-环辛二烯催化氧化性能。在优化反应条件下,10%WO₃-MCF表现出100%的1,5-环辛二烯转化率和98%的氧杂环化合物的选择性和收率,该结果与均相钨酸性能相近。套用实验表明,原位合成方法制备的催化剂与普通浸渍法相比,具有更好的稳定性。WO₃-MCF可以套用四次仍保持较高的催化性能。3.单分散高活性含钨介孔泡沫材料的合成及其在1,5-环辛二烯选择氧化反应中的催化性能研究虽然WO₃-MCF催化剂较均相催化剂有了很大改进,但是ICP测试表明此催化剂存在钨物种的脱落问题,因此需要找寻新的方法避免这一问题的发生。另外由表征可以看出钨物种的存在方式包括单分散的钨物种、二聚或低聚的钨物种、多聚态的钨物种和晶态三氧化钨。为了研究单分散的钨物种对此反应的影响,我们合成了单分散的含钨介孔泡沫材料。将上一章合成的新型含钨介孔分子筛WO₃-MCF,用乙酸铵处理后,得到WO₃-MCF-1。TEM和氮物理吸附表征结果表明,乙酸铵处理后的样品WO₃-MCF-1保持载体原有的孔道结构。XPS、UV-Raman和UV-Vis。DRS表征说明,在10%WO₃-MCF-1催化剂中,钨物种主要以孤立的[WO₄]^2-形式存在;UV-Vis。DRS还证实晶态WO₃首先被洗去,随后是聚集态的钨物种。ICP表征表明,对于原位合成法,在钨含量达到或大于3.94%时,乙酸铵处理后的样品中钨含量保持在0.30%,这一部分钨物种可以稳定存在于MCF骨架中。乙酸铵处理法可以得到含单分散[WO₄]^2-活性中心的催化剂,这种高度分散的钨物种对1,5-环辛二烯的氧化反应具有很高的活性,且该活性组分与载体之间的相互作用很强,能够有效的防止了钨物种的流失,使得催化剂显示出优异的稳定性能。10%WO₃-MCF-1催化剂在1,5-环辛二烯的选择氧化中催化活性最好,TON值为427.2,环氧化合物的选择性高达92.7%,远高于以浸渍法制备的10%WO₃/MCF-1催化剂,其TON值仅为72,环氧化合物的选择性仅为68.5%。由第二部分和第三部分的研究结果可知,催化剂中活性组分钨物种的分散度、存在状态均对催化性能具有很大的影响。4.锚定法合成的HPW-NH₂-MCF催化剂及其在1,5-环辛二烯选择氧化反应中的催化性能的研究虽然上部分工作克服了钨物种的脱落问题,但是反应得到的主产物为1,5-环辛二烯的单环氧化合物,催化剂的总体性能偏低,因此需要寻找一种催化剂,既能得到好的催化性能又能避免活性组分的脱落。因此,我们以氨基化修饰的介孔泡沫材料MCF材料作为载体,通过酸碱中和作用使12-磷钨酸固载在MCF的孔道中,合成了催化剂HPW-NH₂-MCF（简称锚定法合成催化剂）,并与采用简单浸渍法合成的催化剂HPW/MCF进行比较。BET结果表明,APTES的修饰以及HPW的引入都会导致分子筛比表面积降低,孔容减小;TEM结果表明,磷钨酸物种高度分散在MCF中,MCF的孔道结构保持完好。¹³C and ²⁹Si MAS NMR表征证明,APTES被成功嫁接在MCF表面。FT-IR和XPS表征结果表明,HPW和NH₂-MCF之间存在强相互作用。³¹P MAS-NMR表征结果显示HPW-NH₂-MCF上的HPW仍保持其特征Keggin结构。16%HPW-NH₂-MCF,16%HPW-NH₂-SBA-15和16%HPW-NH₂-MCM-41催化性能研究表明,16%HPW-NH₂-MCF的催化性能最好。介孔泡沫催化材料HPW-NH₂-MCF的独特结构,即超大孔径、3-D的孔道结构和由窗口交叉相连的结构单元,有效的提高了反应速率,也提高了氧杂环化合物的收率。在优化反应条件下,16%HPW-NH₂-MCF表现出100%的1,5-环辛二烯转化率和99%的氧杂环化合物选择性。同时套用实验表明,锚定法制备的催化剂可以套用6次,1,5-环辛二烯的转化率仍然高达99%,主要产物氧杂环化合物的选择性仍保持在96%以上。与普通浸渍法制备的16%HPW/MCF催化剂相比,氨基锚定催化剂具有更好的稳定性。非均相测试实验表明16%HPW-NH₂-MCF催化剂是真正的非均相催化剂。5.锚定法合成的Keggin磷钨酸催化剂在其他烯烃选择氧化反应中的性能研究及催化剂低成本化探索由上部分工作可知,锚定法确实优于传统浸渍法,该方法操作较简单,容易控制,能使磷钨酸高度分散在介孔分子筛孔道内,并且HPW和NH₂-MCF之间存在强的相互作用,可以有效阻止HPW的溶脱。因此将这一方法拓展应用于其他烯烃的选择氧化反应中。研究发现24%HPW-NH₂-MCF具有良好的环戊烯催化氧化性能。在优化条件下,此催化剂表现出100%的环戊烯转化率和71.8%的戊二醛选择性。同时套用实验表明,锚定法制备的催化剂可以套用8次,环戊烯的转化率仍然高达99%,主要产物戊二醛的选择性仍保持在60%以上。非均相测试实验表明24%HPW-NH₂-MCF催化剂是真正的非均相催化剂。16%HPW-NH₂-SBA-15具有良好的双环戊二烯催化氧化性能。在优化反应条件下,表现出100%的双环戊二烯转化率和97%的双环戊二烯二环氧化物的选择性。同时套用实验表明,锚定法制备的催化剂可以套用6次,双环戊二烯的转化率仍然高达100%,双环戊二烯二环氧化物的选择性仍保持在96%以上。与普通浸渍法制备的16%HPW/SBA-15催化剂相比,该方法制备的催化剂具有更好的稳定性。非均相测试实验表明16%HPW-NH₂-SBA-15催化剂也是真正的非均相催化剂。MCF载体的合成需要正硅酸乙酯和P123,因此成本较高。我们试图将锚定法应用于自制二氧化硅和商业二氧化硅。研究发现16%HPW-NH₂-SiO₂在1,5-环辛二烯选择氧化反应中也具有良好的催化性能。非均相测试实验表明16%HPW-NH₂-SiO₂在反应中是真正的非均相催化剂。此催化剂可以套用7次仍能保持较好的催化性能,与普通浸渍法制备的催化剂相比,具有更好的稳定性。反应结束后溶液中没有检测到溶脱的HPW,说明催化剂在此体系中非常稳定。16%HPW-NH₂-SiO₂（商业）在1,5-环辛二烯选择氧化反应中也具有良好的催化性能。该催化剂可以套用6次还保持较好活性。套用实验充分说明锚定法制备的催化剂稳定性很好。非均相测试实验也证明16%HPW-NH₂-SiO₂（商业）在反应中是真正的非均相催化剂。更多还原

【Abstract】 As we know,the oxidation of olefins is a very useful and important reaction in organic synthesis.Classic routes for the reaction employ chlorocarbon such as chloroform and 1,2-dichloroethane as solvents and peroxo acids as oxidants.These reaction processes fall short of green chemistry.Nowadays,the development of environmental friendly techniques is one of the prior goals of chemical research,which is especially true in the field of the oxidation of olefins where there is an urgent need to replace wasteful and toxic stoichiometric oxidants with "clean" oxygen donors,such as hydrogen peroxide and oxygen.It is known that oxidation of organic substrates with hydrogen peroxide is very attractive and has been long studied.Hydrogen peroxide as oxidant is riskless and non-polluting. In hydrogen peroxide system,the reaction is catalyzed by a number of transition metal compounds such as W,Mn,Mo,and Rh.Among the most efficient catalysts,tungsten containing compounds are cheap and do not decompose to H₂O₂.Thus,there is considerable interest in the synthesis and characterization of novel tungsten-containing catalysts.It is commonly accepted that 9-oxabicyclo[3.3.1]nonane-2,6-dioles（1） and 2-hydroxy-9-oxabicyclo[3.3.1]nonane-6-one（2） are the major starting material for the synthesis ofγ-butyrolactones.γ-Butyrolactone structure is a versatile building block in organic synthesis since countless compounds containing this function group show interesting biological activity.For example,5-hydroxy-γ-decalactone is a potent cytotoxic agent on different tumor cell lines.Therefore,it is of great significance to develop efficient and accessible approaches to afford these products（1 and 2）.Classic routes for 1 and 2 employ peroxo acid or permanganate as oxidants.However,the performic acid,as well as peracetic acid and permanganate,is expensive chemicals and leads to great amounts of byproducts.Therefore,difficult separation of 1 from the products mixture is inevitable in these routes because of the low conversion and selectivity.Herein we report a green procedure for the O-hetero-cyclization of cycloocta-1,5-diene（COD） by catalytic oxidation with aqueous H₂O₂.The main purpose of this dissertation is to develop novel catalysts that is highly efficient,highly stable and can be reused for several times.In addition,different types of tungsten containing catalyst is investigated,as well as their catalytic activity for the selective oxidation of COD,and all the catalysts have been characterized with various analytical and spectroscopic techniques.1.Green Catalytic Process for the Selective Oxidation of cycloocta-1,5-diene over tungstic acid and phosphotungstic acidNovel one-step green process for the synthesis of compounds（1 and 2） from the selective oxidation of COD has been reported with hydrogen peroxide（H₂O₂） as oxidant,tert-butanol as solvent,and tungstic acid（H₂WO₄） or phosphotungstic acid (H₃PW₁₂O₄₀) as catalyst.It can be seen that the conversion of COD rises with the increase of molar ratios of H₂O₂ to COD.And the molar ratios of H₂O₂ to COD can dramatically affect the yield of the object products.Considering both good catalytic performance and H₂O₂ utility,the 3:1 ratio of the H₂O₂ to COD is needed.It was found that conversion of COD in a fixed reaction period ascends with increasing catalyst dosage,and the amounts of catalysts not only affect the rate of the reaction but also affect the distribution of 1 and 2.For the alcoholic solvents,tert-butanol is the best,the large alkyl of which hinders the formation of ethers.Some other water-soluble solvents, such as 1,4-dioxane,acetonitrile and tetrahydrofuran,having no trend to give ethers, were also tested,and the conversion of COD and selectivity of object products are also high.There is an optimum volume ratio of tert-butanol to COD at which a maximum amount of 1+2 is formed.Initially,with a decrease in the volume ratio from 20 to 5,the selectivity of object products increases from 88 to 98%.Among different heteropoly acids,phosphotungstic acid is the best one in conversion and selectivity of the reaction.It is also found that phosphotungstic acid was very suitable as catalyst for this reaction.The conversion of COD rises with the increase of molar ratios of H₂O₂ to COD.The conversion of COD rises with the increase of catalyst dosage.Tert-butanol is also a good solvent.The conversion of COD and selectivity of 1+2 rises with the decrease of volume ratios of solvent to COD in the volume ratio from 20 to 10,the good results can be got within the volume ratio of 10.The conversion of COD and selectivity of 1+2 rises with the increase of reaction temperature.The optimum temperature is 60℃considering the H₂O₂ utility.This process that doesn’t need any phase-transfer catalysts meets the requirements of environmental protection with H₂O₂ as the oxidant and water as the only by-product.In addition,this method was highly efficient,which accords well with all of the requirements of green chemistry,resulting in its possibility in large-scale industrial production.2.Synthesis of W-containing mesocellular silica foam catalysts and their application in the O-heterocyclization of cycloocta-1,5-diene with aqueous H₂O₂In our previous work,tungstic acid was reported as an efficient homogeneous catalyst for the title reaction.However,the difficulties of separating and recovering the catalysts from the product mixture during the homogeneous process made such catalysts impractical for large-scale industrial production processes.The in situ synthesized method-derived 10 wt.%WO₃-MCF and the impregnated method-derived 10 wt.%WO₃/MCF catalysts both exhibit excellent performances for the target reaction（O-heterocyclization）.The ultralarge mesopores of the catalysts are helpful for the transport of the large raw material and products during the reaction.The heterogeneous tungsten trioxide containing MCF catalyst synthesized via the in situ synthesized method shows higher WO₃ species dispersion compared to the one synthesized by the impregnation method as proved by XRD,TEM,Raman and UV-vis DRS results.According to the XRD result,the tungsten oxide on the catalyst synthesized by the impregnation method is more easily aggregated after the reaction than the one on the catalyst synthesized by the in situ synthesized method.TPR and XRD results show that the 10 wt.%WO₃-MCF catalyst shows stronger interaction between active tungsten oxide species and the MCF material than that of WO₃/MCF catalysts.The recycling experiment results indicate that the in situ synthesized method- derived catalyst shows far better stability than the impregnated one.Although there is detectable leaching of tungsten species from 10%WO₃-MCF based on ICP-AES analysis,the in situ method derived WO₃-MCF catalyst can still be reused for more than 4 times.3.High-activity,single-site mesoporous WO₃-MCF materials for the catalytic epoxidation of cycloocta-1,5-diene with aqueous hydrogen peroxideIn our previous work,WO₃-containing mesocellular silica foam catalysts is highly efficient in the O-heterocyclization of cycloocta-1,5-diene.However,there is detectable leaching of tungsten species from 10%WO₃-MCF based on ICP-AES analysis.So it is important to find a more stable catalyst.According to the characterizations,it can be seen that the tungsten species are presented as the isolated tetrahedral {WO₄} species,low-condensed polymeric tungsten oxide species, high-condensed polymeric tungsten oxide species and a little crystalline WO₃.It is hard to understand the role of the isolated tetrahedral {WO₄} species over the reaction. In the present study,in order to understand the role model of isolated tetrahedral {WO₄} species on mesocellular silica foam materials and how these properties influence the catalytic activity and selectivity,the isolated tetrahedral {WO₄} species doped mesocellular silica foam（MCF） materials are synthesized and systematically characterized by various analytical and spectroscopic techniques,including N₂ sorption,TEM,UV-vis DRS,UV-Raman and XPS.The AMA-treated WO₃-MCF catalysts exhibit good performance which has been attributed to the ultra-large mesopores of the catalysts for this reaction.The AMA-treated catalysts retain the special structure of the supports under the treating conditions.The most isolated tungsten atoms are well embedded in the supports when the catalysts were treated with AMA,which were proved by UV-Vis.DRS,XPS and UV-Raman experiments. The UV-Vis.DRS results also indicate the crystalline tungsten trioxide species were firstly removed,then the polymeric WO₃ species.The tungsten percent comes to a fixed value for the catalysts of different WO₃ loadings as confirmed by ICP method. Different preparation methods lead to different final residual tungsten percent,but only the in situ method can lead to the perfect single-site {WO₄} tetrahedral species. It is also demonstrated from the recycling experiment that the AMA-treated WO₃-MCF catalyst shows excellent stability.4.Preparation and catalytic behavior of highly active and stable amiuopropyl-immobilized phosphotungstie acid on mesoeellular silica foam for the O-heterocyclization of cycloocta-1,5-diene with aqueous H₂O₂Although it is demonstrated from the recycling experiment that the AMA-treated WO₃-MCF catalyst shows excellent stability,the main product is COD epoxide. Hence,there is a strong driving force to find a highly active catalyst without any leaching of tungsten species so that no heavy metal containing waste water was generated.The heteropoly phosphotungstic acid,H₃PW₁₂O₄₀,has been successfully immobilized on the surface of mesoporous MCF,SBA-15 and MCM-41 by means of chemical bonding to aminosilane groups.Characterization results from N₂ sorption indicate that the surface area decreased after grafting amine to silica.The aminopropyl functional groups were successfully grafted on the MCF silica from ¹³C and ²⁹Si MAS NMR results.The strong interaction between the NH₂ groups in the silanes moieties and HPW molecules can be convinced from FT-IR and XPS results.³¹p MAS-NMR indicated that the HPW can keep its Keggin structure after the immobilization.The HPW-NH₂-MCF is highly efficient in the title reaction with a COD conversion up to 100%and（1+2） selectivity up to 98%.Comparison of 16%HPW-NH₂-MCF,16% HPW-NH₂-SBA-15 and 16%HPW-NH₂-MCM-41 reveals that 16%HPW-NH₂-MCF is the most effective one.This finding uncovers that the ultra large pores and the unique three dimensional cell-window of MCF are more favorable for the title reaction than the SBA-15 and MCM-41 counterparts owning only two dimensional pore structures.The HPW-NH₂-MCF could be used for more than six times without any significant loss of activity and leaching of tungsten species in the reaction mixture. The good stability can be attributed to the strong interaction between the -NH₂ groups in the silanes moieties and HPW molecules.4.The study of the selective oxidation of other olefins over the immobilized catalysts and the low cost exploring of the catalystsThe HPW-NH₂-MCF is highly efficient in the selective oxidation of cyclopentene（CPE） to glutaraldehyde（GA） with a CPE conversion up to 100%and GA selectivity up to 71.8%.CPE conversion keeps up to 99%and GA selectivity keeps up to 60%,when the 24%HPW-NH₂-MCF was reused for eight times. Heterogeneous experiment indicates that the 24%HPW-NH₂-MCF catalyst is actually a heterogeneous one.The HPW-NH₂-SBA-15 is highly efficient in the selective oxidation of dicyclopentadiene（DCPD） to dicyclopentadiene dioxide with a DCPD conversion up to 100%and dicyclopentadiene dioxide selectivity up to 97%.DCPD conversion keeps up to 100%and Dicyclopentadiene dioxide selectivity keeps up to 96%,when the HPW-NH₂-SBA-15 was reused for six times.The recycling experiment results indicate that the immobilized catalyst shows much stability than the impregnated one.Heterogeneous experiment indicates that the 16% HPW-NH₂-SBA-15 catalyst is actually a heterogeneous one.The HPW-NH₂-SiO₂ is highly efficient in the O-heterocyclization of COD to 1 and 2 with a COD conversion up to 100%and（1+2） selectivity up to 95.2%.Heterogeneous experiment indicates that the 16%HPW-NH₂-SiO₂ catalyst is actually a heterogeneous one.The recycling experiment results indicate that the immobilized catalyst shows far better stability than the impregnated one.The HPW-NH₂-SiO₂ could be used for more than seven times without any significant loss of activity and leaching of tungsten species in the reaction mixture.The HPW-NH₂-SiO₂（commercial） is highly efficient in the O-heterocyclization of COD to 1 and 2 with a COD conversion up to 100%and（1+2） selectivity up to 95.7%.The HPW-NH₂-SiO₂（commercial） could be used for more than six times without any significant loss of activity and leaching of tungsten species in the reaction mixture.Heterogeneous experiment indicates that the 16% HPW-NH₂-SiO₂ catalyst is actually a heterogeneous one.更多还原