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研究开发了一个实用高效的钯铜共催化体系,1%Pd(OAc)2与10%CuCl2.2H2O双金属组合催化剂在弱碱和0.5 equiv PPh3配体存在下,顺利催化苯并唑类杂环与各种芳基溴的直接芳基化,并得到良好的收率.该钯铜共催化体系具有钯催化计量低、配体廉价易得、底物适用范围广、反应条件温和等特点. 相似文献
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多金属氧簇催化研究进展 总被引:1,自引:0,他引:1
多金属氧簇由于其组成和结构易于调控、具有酸性、氧化还原性、低毒性和低腐蚀性等优点,作为工业催化剂具有广阔的应用前景,是多酸化学领域的研究热点之一。本文综述了近5年来多金属氧簇在催化领域中研究的新进展,主要包括多金属氧簇的酸催化、氧化催化、双功能催化、加氢和活化二氧化碳合成碳酸酯等催化反应以及多金属氧簇的工业化应用等,并对未来发展趋势进行了展望。 相似文献
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Mark A. Maskeri Malte L. Schrader Prof. Dr. Karl A. Scheidt 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(26):5794-5798
Combining biological and small-molecule catalysts under a chemoenzymatic manifold presents a series of significant advantages to the synthetic community. We report herein the successful development of a two-step/single flask synthesis of γ-lactones through the merger of Umpolung catalysis with a ketoreductase-catalyzed dynamic kinetic resolution, reduction, and cyclization. This combined approach delivers highly enantio- and diastereoenriched heterocycles and demonstrates the feasibility of integrating NHC catalysis with enzymatic processes. 相似文献
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Dr. Sachin Handa Daniel J. Lippincott Donald H. Aue Prof. Bruce H. Lipshutz 《Angewandte Chemie (International ed. in English)》2014,53(40):10658-10662
Asymmetric gold‐catalyzed hydrocarboxylations are reported that show broad substrate scope. The hydrophobic effect associated with in situ‐formed aqueous nanomicelles gives good to excellent ee’s of product lactones. In‐flask product isolation, along with the recycling of the catalyst and the reaction medium, are combined to arrive at an especially environmentally friendly process. 相似文献
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随着过渡金属催化的交叉偶联反应的出现,有机合成化学在20世纪的最后25年得到了快速的发展,并且这些反应的重要性被普遍认可.其中,Suzuki偶联反应因其多功能性、兼容性和对包括材料科学和药物合成在内的多种学科的关键贡献,而占据了更加特殊的地位.尽管到2010年为止Suzuki反应已取得重大进展,但随着可持续和绿色化学发展的需求,Suzuki反应的催化体系仍待进一步优化提高.这里概述的催化剂为C-C键的构建提供了方便和绿色的合成途径.在这篇综述中,我们总结了科研工作者对于Suzuki反应在改进催化剂制备策略、优化催化反应条件、提高催化剂重复利用性能和降低催化剂成本方面做的一系列研究. 相似文献
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稀土金属的配位数较高,可通过容纳大型手性配体,构筑手性环境,催化不对称反应的定向发生,在工业生产特别是制药工程中具有重要应用价值.本文以Henry反应、Mannich反应和Strecker反应为例,总结回顾了稀土金属催化剂在此类反应中的设计思路、性能特点与应用前景,旨在展现稀土金属催化剂兼具融合均相催化与异相催化的优势... 相似文献
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《物理化学学报》2010年刊发了89篇与催化相关的文章,其中53篇研究性文章的主题分属于石油加工、催化氧化、催化加氢、生物质转化、光催化、合成气和甲醇转化、理论催化、电催化和环境催化等9个方向.本述评着重介绍了能源转化和利用方面的文章,指出针对我国的可持续发展目标,设计化石能源和可再生能源的廉价、高效、环境友好的催化剂... 相似文献
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Designed Precursor for the Controlled Synthesis of Highly Active Atomic and Sub‐nanometric Platinum Catalysts on Mesoporous Silica
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Dr. Sudipta De Dr. Maria V. Babak Max J. Hülsey Prof. Dr. Wee Han Ang Prof. Dr. Ning Yan 《化学:亚洲杂志》2018,13(8):1053-1059
The development of new methods to synthesize nanometric metal catalysts has always been an important and prerequisite step in advanced catalysis. Herein, we design a stable nitrogen ligated Pt complex for the straightforward synthesis by carbonization of uniformly sized atomic and sub‐nanometric Pt catalysts supported on mesoporous silica. During the carbonization of the Pt precursor into active Pt species, the nitrogen‐containing ligand directed the decomposition in a controlled fashion to maintain uniform sizes of the Pt species. The nitrogen ligand had a key role to stabilize the single Pt atoms on a weak anchoring support like silica. The Pt catalysts exhibited remarkable activities in the hydrogenation of common organic functional groups with turnover frequencies higher than in previous studies. By a simple post‐synthetic treatment, we could selectively remove the Pt nanoparticles to obtain a mixture of single atoms and nanoclusters, extending the applicability of the present method. 相似文献
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甲烷合成甲醇的方法包括间接法和直接催化氧化(DMTM)法,但是间接法对设备要求高,且甲烷转化率与甲醇选择性均不理想,DMTM法可通过一步反应高选择性制备甲醇,有巨大的应用潜力。对于甲烷DMTM法合成甲醇,均相催化体系通常需要特殊反应介质与贵金属催化剂相结合,虽然反应效率高,但对反应设备有腐蚀性,产物不易分离,应用前景差。液相-异相催化一般使用H_(2)O_(2)作为氧化剂,Au、Pd、Fe和Cu等金属元素作为催化剂主要活性组分,·OH是主要的氧化活性物,可在低温下实现甲烷的活化氧化。因此,异相催化体系是目前研究的主流。气相-异相催化主要使用O_(2)和N_(2)O为氧化剂,前者氧化性更强,后者对于产品选择性更好,此外,厌氧体系中H_(2)O也可直接作为氧供体,常用Cu、Fe、Rh等元素作为催化剂。沸石分子筛是使用最广泛的载体,金属氧化物、金属有机骨架化合物(MOFs)和石墨烯也均有涉及,多金属协同催化已经取得了很好的效果。本文主要总结与概述了热催化甲烷直接催化氧化制备甲醇的近年相关研究,并对今后的研究方向做出了展望。 相似文献
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Patrik Krumlinde Krisztián Bogár Dr. Jan‐E. Bäckvall Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(13):4031-4036
Enzyme‐ and ruthenium‐catalyzed dynamic kinetic asymmetric transformation (DYKAT) of bicyclic diols to their diacetates was highly enantio‐ and diastereoselective to give the corresponding diacetates in high yield with high enantioselectivity (99.9 % ee). The enantiomerically pure diols are accessible by simple hydrolysis (NaOH, MeOH), but an alternative enzyme‐catalyzed ester cleavage was also used to give the trans‐diol (R,R)‐ 1 b in extremely high diastereomeric purity (trans/cis=99.9:0.1, >99.9 % ee). It was demonstrated that the diols can be selectively oxidized to the ketoalcohols in a ruthenium‐catalyzed Oppenauer‐type reaction. A formal enantioselective synthesis of sertraline from a simple racemic cis/trans diol 1 b was demonstrated. 相似文献
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Siliang Ming Dr. Saira Qurban Prof. Dr. Yu Du Prof. Dr. Weiping Su 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(50):12742-12746
Unlike the comprehensive development of tandem multi-metallic catalysis, bimetallic synergistic catalysis has been challenging to achieve high stereoselectivity with the generation of multi-stereogenic centers. Herein, an efficient synergistic catalysis for the diastereo- and enantioselective synthesis of multi-substituted tetrahydrofuran derivatives has been developed. Under mild reaction conditions, a series of target molecules with three consecutive stereocenters were synthesized by a palladium(0)/rhodium(III) bimetal-catalyzed asymmetric decarboxylative [3+2]-cycloaddition of vinylethylene carbonates with α,β-unsaturated carbonyl compounds. The corresponding adducts were obtained with moderate to high yields (67 %∼98 %) and excellent stereoselectivities (>20 : 1 d.r., up to 99 % ee). 相似文献
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Norbert Strter William N. Lipscomb Thomas Klabunde Bernt Krebs 《Angewandte Chemie (International ed. in English)》1996,35(18):2024-2055
Numerous studies, both in enzymatic and nonenzymatic catalysis, have been undertaken to understand the way by which metal ions, especially zinc ions, promote the hydrolysis of phosphate ester and amide bonds. Hydrolases containing one metal ion in the active site, termed mononuclear metallohydrolases, such as carboxypeptidase. A and thermolysin were among the first enzymes to have their structures unraveled by X-ray crystallography. In recent years an increasing number of metalloenzymes have been identified that use two or more adjacent metal ions in the catalysis of phosphoryl-transfer reactions (R-OPO3 + R′-OH → R′-OPO3 + R-OH; in the case of the phosphatase reaction R′-OH is a water molecule) and carbonyl-transfer reactions, for example, in peptidases or other amidases. These dinuclear metalloenzymes catalyze a great variety of these reactions, including hydrolytic cleavage of phosphomono-, -di- and -triester bonds, phosphoanhydride bonds as well as of peptide bonds or urea. In addition, the formation of the phosphodiester bond of RNA and DNA by polymerases is catalyzed by a two-metal ion mechanism. A remarkable diversity is also seen in the structures of the active sites of these di- and trinuclear metalloenzymes, even for enzymes that catalyze very similar reactions. The determination of the structure of a substrate, product, stable intermediate, or a reaction coordinate analogue compound bound to an active or inactivated enzyme is a powerful approach to investigate mechanistic details of enzyme action. Such studies have been applied to several of the metalloenzymes reviewed in this article; together with many other biochemical studies they provide a growing body of information on how the two (or more) metal ions cooperate to achieve efficient catalysis. 相似文献
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Dr. Adrien Quintard Prof. Jean Rodriguez 《Angewandte Chemie (International ed. in English)》2014,53(16):4044-4055
Iron cyclopentadienone complexes have recently received particular attention in organic chemistry. This is due to their easy synthesis from simple and cheap materials, air–water stability, and most importantly for their unique catalytic features arising from the presence of a non‐innocent ligand, triggering powerful redox properties. Herein we discuss the properties of such complexes from synthetic and mechanistic points of view, and their applications in original redox‐neutral transformations in both racemic and enantioselective series. 相似文献
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过渡金属催化的烯丙基取代反应是一类重要且实用的有机化学反应, 可以立体选择性地高效构建碳-碳键和碳-杂键. 可见光氧化还原催化可以利用绿色清洁的可见光能源在较为温和的条件下产生自由基或者自由基离子等高反应活性的反应中间体, 被广泛地应用于有机合成中, 逐渐发展成为一种重要的合成工具. 鉴于烯丙基取代反应的重要性, 过渡金属与光氧化还原协同催化的烯丙基取代反应逐渐引起化学家的兴趣. 该协同催化的策略可以实现单一过渡金属催化难以实现的烯丙基取代反应, 反应的区域选择性和立体选择性也体现出不同的特点, 有望发展成为单一金属催化的烯丙基取代反应的重要补充. 本文综述了近年来不同过渡金属与可见光氧化还原协同催化的烯丙基取代反应的研究进展. 相似文献
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Piovesana S Scarpino Schietroma DM Bella M 《Angewandte Chemie (International ed. in English)》2011,50(28):6216-6232
This Minireview focuses on asymmetric reactions mediated by two distinct chiral catalysts (chiral multiple catalysis). Initially, this approach appears unconventional, but indeed it allows a fast multidimensional optimization and fine-tuning of the catalytic system required to perform a given transformation. Herein, this emerging concept is presented and its potential applications are highlighted. 相似文献
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Guangda Xu Guoqiang Yang Yue Wang Pan‐Lin Shao Jia Ning Nicolette Yau Bing Liu Yunbo Zhao Ye Sun Xinxin Xie Shuo Wang Yao Zhang Lixin Xia Yu Zhao 《Angewandte Chemie (International ed. in English)》2019,58(40):14082-14088
We present an economical catalytic procedure to convert readily available 1,2‐diaminobenzenes and terminal epoxides into valuable 1,2,3,4‐tetrahydroquinoxalines in a highly enantioselective fashion. This procedure operates through relay zinc and iridium catalysis, and achieves redox‐neutral and stereoconvergent production of valuable chiral heterocycles from racemic starting materials with water as the only side product. The use of commercially available reagents and catalysts and a convenient procedure also make this catalytic method attractive for practical application. 相似文献
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Dr. Taku Kitanosono Prof. Dr. Shū Kobayashi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(43):9408-9429
Ever-evolving catalyst advances in synthetic protocols using water as a reaction medium have enriched the understanding of sustainable organic chemistry. Because conventional classification and definitions were ambivalent, it is proposed here that catalytic reactions using water be collectively called to be “in water”, with further classification into seven types. When accelerated in water as heterogeneous mixtures, the reactions can be regarded as following an “on-water” mechanism. The original term “on water” coined by Sharpless is incongruous with catalytic reactions, whereas on-water used in this review covers all the interfaces involving water where chemical reactions are accelerated. As a result of the unconcluded dispute on the antiquated catalyst-free “on water” model, the modified model defines three water layers: water molecules that are oriented to extrude protons toward the oil phase in the inner layer, those enwrapped by a secondary layer, and finally the bulk water layer. In light of the latitudinous outlook on the role of water at the interface, selected examples of reactions, in particular those reported over the past decade, that follow an “on-water” mechanism are reviewed herein. 相似文献