聚合物固载催化剂的研究进展

综述了近年来聚合物固载催化剂的研究进展。介绍的聚合物固载催化剂有6类，包括离子交换树脂催化剂、聚合物固载的相转移催化剂、聚合物固载的酸催化剂、聚合物固载的碱催化剂、聚合物固载的金属催化剂、聚合物固载的生物催化剂等。     

烯烃氢甲酰化固载化催化剂研究进展

针对不同载体和固载化方法,综述了近年来固载化催化剂在烯烃氢甲酰化反应中的研究进展。重点介绍了以有机聚合物、分子筛、二氧化硅和活性炭等为载体的固载化催化剂的特点及其性能,并对各种固载化催化剂存在的问题和发展前景进行了分析。     

固载化L-脯氨酸及其衍生物的最新研究进展

近年来，固载化L-脯氨酸及其衍生物手性催化剂因其具有均相催化剂的高活性和高选择性以及非均相催化剂的高循环使用性，被广泛用于催化不对称有机化学反应。本文简单介绍了L-脯氨酸及其衍生物的种类，包括4-羟基-L-脯氨酸、脯氨醇醚类等；重点阐述了固载L-脯氨酸类催化剂的载体类型和固载方法，催化剂载体类型主要包括离子液体、无机纳米粒子、有机聚合物以及新出现的聚合物离子液体和有机-无机杂化微球，固载方法主要包括硅烷化反应法、点击化学法以及可逆加成-断裂链转移（RAFT）聚合法，并对不同载体及固载方法的优缺点进行了总结。最后，针对目前固载化L-脯氨酸类催化剂存在的问题进行了原因分析并提出了改进建议，为以后新型固载化催化剂的研究开发提供了可能。     

聚合物固载型磷钨酸催化剂的制备与性能研究

合成了交联型的丙烯酰胺共聚物 ;制备了聚合物键合固载磷钨酸型催化剂 ;考察了催化剂在乙酸丁酯合成反应中的催化性能以及再生性能。结果表明含季铵离子和 NH2 官能团的交联型聚合物与磷钨酸反应 ,生成了电荷转移盐 ( TCT) ,此类聚合物固载型电荷转移杂多酸具有较强的催化性能和一定的再生性能。     

聚合物固载氧化剂的研究进展

介绍了聚合物固载的过硼酸钠、聚合物固载的氧化三甲胺、聚合物固载的溴化物、聚合物固载的Cr(Ⅵ)氧化剂,综述了它们各自的性能和优缺点,以及改进缺陷的可能性和方法,预测了聚合物固载氧化剂的发展趋势。     

三相相转移催化合成对苯二甲酰氯的研究

合成制备了既有聚醚链段又有季铵盐的新型聚合物固载相转移催化剂,并以之用于对苯二甲酸合成标题化合物.考察了催化剂、氯化亚砜、甲苯等的用量对反应收率的影响,得到了适宜的合成工艺条件为:n(TPA):n(SOCl2):n(PhCH3):n(PTC)=1:3:3:0.06,反应温度85 ℃,反应时间6 h.在该条件下,对苯二甲酰氯收率>89.6%,HPLC法测定纯度>99.6%,该聚合物固载相转移催化剂可重复使用6次以上.     

负载金属卟啉用于催化氧化反应的进展

综述了近年来国内外金属卟啉在固载催化领域应用进展,包括:分子筛,蒙脱石,高岭石,硅胶,玻璃,炭黑,金等无机载体,以及聚苯乙烯,树脂,橡胶,高分子多糖,金属卟啉聚合物等有机载体.固载金属卟啉模拟酶催化剂在催化氧化反应中将有更大的应用前景.     

杂多酸-聚合物复合膜催化合成丙烯酸-2-甲氧基乙酯

制备了Keggin型磷钨酸-乙烯醇复合膜催化剂,用FT-IR等分析方法对催化剂进行了表征。以该复合膜催化合成丙烯酸-2-甲氧基乙酯作为探针反应,考察了反应物配比、催化剂用量、反应时间及催化剂重复使用次数对催化剂活性的影响。研究发现,该固载型杂多酸催化剂对丙烯酸-2-甲氧基乙酯合成具有较高的催化活性,此类聚合物固载型杂多酸采用有机无机复合的方式形成,具有制备简单、催化活性较高、可再生、催化剂易回收等优点。在最佳反应条件下,丙烯酸-2-甲氧基乙酯的收率可达到95.4%以上。     

Progress of immobilized catalysts for ethylene oligomerization to α-olefin

综述了乙烯齐聚制a-烯烃固载化催化剂的研究新进展。通过讨论固载化催化剂的载体结构和性质、固载化方法、助催化剂以及主催化剂与载体的相互作用等对乙烯齐聚反应的影响,指出固载化催化剂由于载体与活性金属中心的相互作用改变了原均相催化剂活性中心的有规立构及定向性,使其活性金属中心的电子密度发生变化是导致固载化催化剂的活性与原均相催化剂不同的重要原因,且多数固载化催化剂的活性有所降低。另外,对固载化催化剂活性中心及反应中间物种形成的催化反应机理进行了简单阐述。最后指出开发新型载体及更为简单有效的固载化方法,明晰主客体之间的相互关系是今后乙烯齐聚固载化催化剂研究的重要任务。     

乙烯齐聚制α-烯烃固载化催化剂的研究进展

综述了乙烯齐聚制α-烯烃固载化催化剂的研究新进展.通过讨论固载化催化剂的载体结构和性质、固载化方法、助催化剂以及主催化剂与载体的相互作用等对乙烯齐聚反应的影响,指出固载化催化剂由于载体与活性金属中心的相互作用改变了原均相催化剂活性中心的有规立构及定向性,使其活性金属中心的电子密度发生变化是导致固载化催化剂的活性与原均相...     

可溶聚合物支载催化剂

可溶聚合物支载催化剂是当今“绿色化学”研究的热点问题之一。本文介绍了近几年来可溶聚合物支载催化剂,包括可溶聚乙二醇、可溶聚丙烯酰胺和可溶非交联聚苯乙烯支载催化剂的研究情况及其在有机合成中的应用。     

Hydrogenation of Citral Over a Polymer Fibre Catalyst

A polymer-supported Pd catalyst was investigated in hydrogenation of citral (3,7-dimethyl-2,6-octadienal), which is a stereoisomer with an isolated and a conjugated double bond as well as a carbonyl group. The catalyst was a fibrous polymer-supported catalyst modified with functional groups and immobilized metals. A comparison of the polymer-supported catalyst with conventional catalysts was made.     

Polymer-supported N-heterocyclic carbene-iron(III) catalyst and its application to dehydration of fructose into 5-hydroxymethyl-2-furfural

Polymer-supported NHC–metal catalysts were prepared from chloromethyl polystyrene resin via two-step reaction. Metals were loaded into 1.6 – 16 mol% of total imidazolium and the remaining imidazolium chloride salt provided ionic liquid moiety. The formation of metal complex with the polymer-supported NHC ligand was analyzed by ATR FT-IR, XRD, and XPS. The synthesized polymer-supported NHC–metal catalysts were applied to the dehydration of fructose into HMF. The environmentally benign and inexpensive polymer-supported NHC–Fe^III catalyst showed good catalytic activity and yielded HMF at 73% (with a conversion of 97%). It could also be reused without significant loss of catalytic activity.     

Polymers as Catalysts

Polymers have been widely used as catalysts or catalyst supports and the various applications can be categorised conveniently into four groups (a) catalysis by soluble linear polymers, (b) catalysis by ion exchange resins, (c) polymer-supported ‘homogeneous’ metal complex catalysts and (d) polymer-supported phase transfer catalysts. A brief review of each of these is given, with citation of some of the more recent and important examples which illustrate some of the basic principles involved.     

Vanadium Complexes Based Polymer Supported Catalysts: A Brief Account of Research from Our Group

Solid supported catalysts can go a long way in developing catalyst based technology because of their high efficiency with recyclability and easy separation from the reaction mixture. Immobilizations of homogeneous catalysts through covalent bond with chloromethylated polystyrene cross-linked with divinylbenzene and develop them as environmentally safe heterogeneous catalysts for oxidation reaction have attracted attention in recent years. Recently, effort from our research laboratory was to synthesize new recyclable polymer-supported vanadium complexes based heterogeneous catalysts. Thus, chloromethylated polystyrene cross linked with 5% divinylbenzene was used as support to prepare variety of polymer supported vanadium catalysts. These catalysts have successfully been used for the oxidation and oxidative bromination of various organic substrates. Keeping in mind the industrial usage of these heterogeneous catalysts, the leaching and recycle ability of all polymer-supported catalysts have also been tested. Most catalysts are stable and do not leach during the catalytic reactions.     

Polystyrene-supported acid catalysis

The present state of polymer-supported acid catalysis is considered. Models describing the catalytic action of gel-like and macroporous resin catalysts are presented. By chemical modification of poly (styrene-co-divinylbenzene) matrices, e.g. different ways of sulphonation, nitration, chlorination, fluorination and sulphoalkylation, the activity/selectivity and thermal stability of sulphonic acid resin catalysts can be improved. The synthesis of polymer-supported Lewis acids is described. By comparison to AlCl₃ higher catalytic activities are obtained with the use of AlBr₃.     

The use of soluble polymers to effect homogeneous catalyst separation and reuse

The use of soluble polymeric ligands for homogeneous catalysts separation is reviewed with emphasis on work from the author's laboratory. Examples discussed include polyethylene-bound catalysts, poly(alkene oxide)-bound catalysts, poly(N-isopropylacrylamide)-bound catalysts, fluorous polymer-bound catalysts and amphoteric polymer-bound catalysts. The utility of these systems is also discussed in the broader context of polymer-supported catalysis and the advantages and limitations of soluble polymeric ligands are discussed in this context.     

Readily prepared heterogeneous molybdenum-based catalysts as highly recoverable,reusable and active catalysts for alkene epoxidation

Polymer-bound aliphatic amines were prepared readily from Merrifield resin and used as supports for immobilization of molybdenum hexacarbonyl. The high activity of these polymer-supported molybdenum catalysts has been demonstrated in epoxidation of various alkenes in the presence of tert-butylhydroperoxide (TBHP). These new heterogenized molybdenum epoxidation catalysts can be recovered and reused several times without significant loss of their activities.     

Chloromethyl polystyrene supported dendritic Sn complexes,preparation and catalytic Baeyer–Villiger oxidation

Dendritic Sn complexes were successfully incorporated to chloromethyl polystyrene through solid phase synthesis methodology and exhibited to be promising catalysts for the Baeyer–Villiger oxidation of ketones with hydrogen peroxide. Several cyclic and acyclic ketones were oxidized by hydrogen peroxide in a reaction catalyzed by these polymer-supported dendritic Sn complexes with high conversion and selectivity. The catalysts can be prepared in large scale in a simple manner without the utilization of any expensive materials and can be recycled as heterogeneous catalysts.