四膦配体/钯体系催化无铜Sonogashira偶联反应

以环己二胺为骨架的含氮四膦配体N,N,N',N'-四[(二苯基膦)甲基]环己二胺和钯组成的催化体系用于苯乙炔和芳卤的Sonogashira反应,该催化体系对卤代芳烃显示了良好的官能团容忍性。结果显示空间位阻的影响大于电子效应,通常能与金属配位使得金属催化剂失活而难以顺利反应的含N杂环化合物,3-溴喹啉以99%的收率获得相应的产物,活性较低的氯代底物,3-氯吡啶的目标产物产率为90%。     

无配体负载钯催化Suzuki偶联反应的研究进展

金属钯催化的Suzuki偶联反应是碳一碳偶联反应中的最重要的反应之一。传统的均相催化体系具有很多的不足,如产物与催化剂不易分离、原料价格昂贵、催化剂不能重复使用等,而使用无配体负载钯的催化剂可有效地解决上述问题。综述了近些年来无配体材料负载钯催化Suzuki偶联反应的研究进展,载体包括碳材料、多孔分子筛、水滑石、高分子材料、金属氧化物、硅藻土、纤维素、磷灰石和氟硅胶等。     

硫化钯催化剂的合成及其应用研究进展

在非均相催化反应中,硫化钯作为催化剂的应用具有重要意义。综述了负载型和非负载型硫化钯的合成方法,重点讨论在气相或液相条件下前驱体、反应温度、反应气氛及载体对合成硫化钯晶相的影响,初步分析硫化钯在催化领域中的应用及未来的发展趋势。     

非均相Fenton催化剂用于降解染料废水的实验研究进展

对非均相Fenton催化剂用于降解染料废水的研究现状作了较为详细的总结和评述,并指出了未来的发展方向。     

均相肟钯配体催化剂的制备及催化Suzuki反应的研究

制备了4-羟基苯乙酮肟钯配体催化剂和2-甲基-4-羟基苯乙酮肟钯配体催化剂。通过FT-IR、UV-Vis、XPS等分析方法对上述催化剂进行了表征,考察了反应条件对催化剂催化性能的影响。实验结果表明,在水/乙醇混合溶剂中、碳酸钾作碱、反应温度为30℃、反应0.5h、催化剂用量为0.25mol‰的钯含量时,催化溴代芳烃与苯硼酸的Suzuki反应产物收率大于90%。     

冷冻干燥法制备壳聚糖/粘土多孔微球负载钯催化剂的性能研究

利用冷冻干燥法制备得到了具有多孔结构的壳聚糖/粘土(蒙脱土)微球负载钯催化剂,催化剂孔径尺寸较大(100μm)。该催化剂应用于典型丙烯酸丁酯与芳基碘系物的Heck反应时,有较高的催化活性。加入适量粘土使壳聚糖分子链能有效地插入到蒙脱土的片层间,良好的插层结构有助于提升催化材料的耐热性和机械性能。相应地,壳聚糖/粘土多孔微球负载钯催化剂比纯壳聚糖负载钯多孔微球催化剂有更高的重复使用性能。     

负载钯及非钯型Suzuki偶联反应催化剂体系的研究进展

Suzuki偶联反应是现代有机合成化学中构筑碳碳键的最有效方法之一。传统的Suzuki反应催化剂主要是Pd(PPh3)4、Pd(OAc)2等均相催化剂。这类催化剂的活性较高,但其价格高、化学稳定性较差、难以与反应液分离和回收再利用等缺点也是不容忽视的。近年来,人们开发了一系列具有不同的钯材料载体(碳材料、高分子材料以及无机材料等)的非均相催化剂体系,以及基于Ni、Cu、Mn等过渡金属的新型催化体系。这些新型的催化剂体系的发展有效地解决了上述均相催化剂的不足。综述了近来Suzuki反应在负载催化剂和非钯催化剂方面的研究进展。     

介绍具有半活性配体的金属有机化合物

介绍了一些具有半活性配体的金属有机化合物的反应性及其催化作用。     

过硫酸盐非均相催化材料研究进展

综述了近几年关于活化过硫酸盐非均相催化材料的研究进展,包括金属催化材料、非金属催化材料和金属-非金属复合材料。阐述了基于"以废治废"新理念的非均相催化材料相关研究成果,其中碳催化材料是主要的不掺杂金属元素就可以有效活化过硫酸盐的非金属材料。     

Suzuki偶联反应中钯配合物催化剂的研究进展

Suzuki偶联反应是在零价钯配合物催化剂的催化下,芳基硼酸与卤代芳烃进行的交叉偶联反应,可以高效、高选择性地构建C-C键.钯配合物催化剂对Suzuki偶联反应的活性和选择性起着决定性的影响,是研究Suzuki偶联反应的关键.对含有膦配体、N-卡宾配体、亚胺配体、胺配体和其它配体的钯配合物催化剂催化效果进行了综述.     

Fine Chemical Synthesis with Homogeneous Palladium Catalysts: Examples,Status and Trends

During the last decade several palladium-catalyzed reactions have been developed and optimized to a stage that enables application on an industrial scale. The importance of these reactions as novel key steps for fine chemical synthesis is shown. Examples include palladium-catalyzed Heck, Suzuki and Sonogashira coupling reactions, telomerization of 1,3-butadiene with nucleophiles, and carbonylation of aromatic and benzylic halides.     

Tuning the Selectivity of Heterogeneous Catalysts: A Trimetallic Approach to Reductive Coupling of Chloroarenes in Water

Reductive homocoupling of chlorobenzenes to the respective biphenyls affords high yields (93–95%), in the presence of catalytic PEG‐400 and 0.4 mol % of a recycleable, heterogeneous trimetallic catalyst (4% Pd, 1% Pt, and 5% Bi on carbon). The competing reduction process is minimized. The catalytic cycle is completed using hydrogen gas, or formate + water or zinc + water mixtures, which generate dihydrogen in situ. Primary kinetic data and some process parameters are studied. The roles of the Pd, Pt, and Bi, different reducing agents, and the phase‐transfer agent are discussed. The reaction mechanism is proposed to depend on the relative concentration of hydride species in the immediate vicinity of the palladium metal.     

非均相催化法生产生物柴油的研究进展

综述了国内外非均相催化法生产生物柴油的现状,介绍了非均相固体酸催化剂、固体碱催化剂和固定化生物酶的最新研究进展,展望了未来生物柴油生产技术的发展趋势。     

Heterogeneous Palladium Catalysts Applied to the Synthesis of 2‐ and 2,3‐Functionalised Indoles

Heterogeneous palladium catalysts ([Pd(NH₃)₄]²⁺/NaY and [Pd]/SBA‐15) were applied to the synthesis of 2‐functionalised indoles, giving generally high conversions and selectivities (>89% yield) using only 1 mol % [Pd]‐catalyst under standard reaction conditions (polar solvent, 80 °C). For the synthesis of 2,3‐functionalised indoles by cross‐coupling arylation, the [Pd]/SBA‐15 catalyst was found to be particularly interesting, producing the expected compound with =35% yield after 12 days of reaction, which is comparable to the homogeneous catalyst, Pd(OAc)₂ (=48% yield). In the course of the study, the dual reactivity of the indole nucleus was demonstrated: aryl bromides gave clean C C coupling while aryl iodides led to a clean C N coupling.     

无机物负载型钯催化剂的研究进展

钯催化剂是重要的金属催化剂,近年来,负载型钯催化剂作为一类新型催化剂广受关注。介绍了以硅胶、MCM-41分子筛、活性炭和金属氧化物等无机物为载体的负载型钯催化剂的特征及应用,并展望了其在不对称反应中的开发应用前景。     

Supported Palladium Catalysts for Suzuki Reactions: Structure‐Property Relationships,Optimized Reaction Protocol and Control of Palladium Leaching

Palladium on metal oxides and on activated carbon with particular properties (high palladium dispersion, low degree of reduction, water content) are shown to be highly active (tunrover number, TON=20,000; turnover frequency, TOF=16,600), selective and robust catalysts for Suzuki cross‐couplings of aryl bromides and activated aryl chlorides. Catalysts and reaction protocol offer combined advantages of high catalytic efficiency under ambient conditions (air and moisture), easy separation and reuse and quantitative recovery of palladium. The palladium concentration in solution during the reaction correlates clearly with the progress of the reaction and indicates that dissolved molecular palladium is in fact the catalytically active species. Dissolved palladium is redeposited onto the support at the end of the reaction. Additional minimization of the palladium content in solution (down to 0.1 ppm) could be achieved by simple procedures which meet the requirements of pharmaceutical industry.     

Suzuki–Miyaura Cross‐Coupling With Quasi‐Heterogeneous Palladium

The Suzuki–Miyaura cross‐coupling reaction using heterogeneous Pd/C has a homogeneous component. The soluble palladium concentration increases during the reaction reaching a maximum at ca. 90% conversion before falling to <4 ppm.