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手性修饰金属催化剂是最具发展潜力的多相不对称催化剂之一。本文综述了近年来三个具有代表性的多相不对称氢化反应体系的研究进展,即酒石酸修饰镍催化剂催化β-酮酯不对称加氢体系、金鸡纳生物碱修饰铂催化剂催化α-酮酯不对称加氢体系以及金鸡纳生物碱修饰钯催化剂催化C=C和C=N双键不对称加氢体系。概述了催化体系的影响因素,探讨了酒石酸及金鸡纳生物碱修饰型催化剂的手性识别机理模型。指出开发高效催化剂,修正或提出手性识别机理模型仍是今后多相不对称催化氢化反应研究的方向。 相似文献
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对手征性二茂铁膦的合成及其过渡金属配合物在催化不对称合成中的应用作了概述。讨论了手征性二茂铁烷基胺的不对称锂化反应机理,手征性二茂铁膦的镍、钯配合物催化不对称格氏偶合反应,钯、铂、铑配合物催化不对称硅氢化反应,铑配合物催化不对称氢化反应,钴配合物催化不对称氢迁移反应,钯配合物催化不对称环化反应,等等。 相似文献
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综述了水/有机两相"温控相转移催化"的原理,在此基础上设计、合成了以非离子型水溶性膦配体和两性双吡啶配体,并与过渡金属络合制备出温控相转移催化剂。综述了其在水/有机两相CO还原,烯烃加氢和Heck反应中的应用效果。 相似文献
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将钌基配合物催化剂固载于氯甲基化后的交联聚苯乙烯树脂上,催化超临界二氧化碳加氢反应。结果表明,多种类型的膦配体均能够与过渡金属钌原子配位催化二氧化碳加氢反应,但由于各种膦配体物化性质的差异,形成的活性物种具有不同的结构和催化性能。双齿膦配体形成的钌基配合物的加氢活性均高于单齿膦配体。 相似文献
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催化氢化是有机合成中较常用的方法之一。均相催化氢化是近廿年发展起来的,而利用手性催化剂进行均相催化氢化还原在不对称合成中的应用,只是近十年来才有较大的发展。手性催化剂是利用手性膦、手性碳或不对称分手与金属铑、钌等络合而制成的。用这些手性催化剂对某些烯和酮等化合 相似文献
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合成了水溶性配体三苯基膦间单磺酸(TPPMS)、三苯基膦间三磺酸(TPPTS)、2,2'-联毗啶-5-磺酸及相应的铑系列水溶性金属有机化合物, 并用相关体系进行了常压环己烯催化加氢反应。结果表明在常压下Rh-EDTA、RH-TPPMS、Rh-TPPTS、RH-联吡啶-5-磺酸等对催化环己烯加氢具有一定的活性, 在水/有机两相反应体系中, 由于催化剂在水中有相当的溶解度, 使反应后催化剂分离简单、快捷, 产物中催化剂残留少。由于烯烃的催化加氢反应可能是在水相中进行, 共溶剂及快速搅拌是必需的。 相似文献
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Asymmetric hydrogenation is one of the most important catalytic methods for the preparation of optically active compounds. For a long time the range of olefins that could be hydrogenated with high enantiomeric excess was limited to substrates bearing a coordinating group next to the C+C bond. We have found a new class of catalysts, iridium complexes with chiral P, N ligands, that overcome these limitations. For a wide range of unfunctionalized olefins, excellent enantioselectivities could be achieved. Because these catalysts do not require the presence of any particular functional group in the substrate, they considerably broaden the scope of asymmetric hydrogenation. In addition, promising results were also obtained with certain functionalized alkenes, furans, and benzofurans. 相似文献
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Carl A. Busacca Bo Qu Nicole Grt Keith R. Fandrick Anjan K. Saha Maurice Marsini Diana Reeves Nizar Haddad Magnus Eriksson Jiang‐Ping Wu Nelu Grinberg Heewon Lee Zhibin Li Bruce Lu Dajun Chen Yaping Hong Shengli Ma Chris H. Senanayake 《Advanced Synthesis \u0026amp; Catalysis》2013,355(8):1455-1463
The modular nature of the BIPI ligands allows for systematic optimization of each ligand region. The development of ligands optimized for asymmetric hydrogenation of the challenging unfunctionalized olefin substrate class is described. The naphthyl peri position, C‐8, has been identified as a critical stereocontrol element in the design of these ligands. Highly enantioselective ligands suitable for hydrogenation of tri‐ and tetrasubstituted olefins are detailed. 相似文献
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Manfred T. Reetz 《Catalysis Today》1998,42(4):2061-411
The concept of covalently connecting a catalytically active transition metal center with a water-soluble receptor (host molecule) makes a new type of supramolecular catalysis possible in which the features of molecular recognition, phase transfer catalysis and transition metal catalysis are combined in a single system. The first examples of this principle make use of the commercially available β-cyclodextrin (β-CD) as the receptor and rhodium complexes of diphosphanes as the catalytically active center, these being covalently connected to one another via a spacer. In competitive hydrogenation of certain olefins unusual degrees of substrate selectivity based on the molecular recognition are observed, not possible by conventional transition metal catalysts. The two-phase (H2O/organic) hydrogenation of nitro-aromatics also is a smooth process with these supramolecular catalysts. They also constitute an unusually active catalyst system for the selective hydroformylation of higher olefins such as 1-octene in a two-phase system. 相似文献
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Hai‐Feng Zhou Qing‐Hua Fan Wei‐Jun Tang Li‐Jin Xu Yan‐Mei He Guo‐Jun Deng Li‐Wen Zhao Lian‐Quan Gu Albert S.C. Chan 《Advanced Synthesis \u0026amp; Catalysis》2006,348(15):2172-2182
Polyethylene glycol (PEG) was found to be an inexpensive, non‐toxic and recyclable reaction medium for ruthenium‐ and rhodium‐catalyzed asymmetric hydrogenation of 2‐arylacrylic acids (Ru‐catalyzed CC bond reduction), enamides (Rh‐catalyzed CC bond reduction), β‐keto esters and simple aromatic ketones (Ru‐catalyzed CO bond reduction). In all cases, high catalytic activities and enantioselectivities have been achieved, which are comparable to those obtained in conventional organic solvent systems. The Ru and Rh catalysts prepared with commercially available chiral diphosphine ligands could be readily recycled by simple extraction, as in the case of ionic liquids, and reused up to nine times without obvious loss of catalytic activity and enantioselectivity. The reduced products were obtained from the extracts in high isolated yields. These results indicate that PEGs as new reaction media are attractive alternatives to room temperature ionic liquids. 相似文献
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近年来,通过烯烃官能团化构建有机化合物成为有机合成领域的研究热点之一。当选择种类、晶体结构和性能多样的过渡金属配合物作为催化剂时,这类反应具有高效、高选择性且成本低的特点。本文总结了近五年来利用过渡金属盐及其配合物作为催化剂,经过自由基反应历程实现未活化烯烃官能团化的研究进展,其反应特点是在过渡金属催化下,烯烃生成自由基并与其它底物或试剂偶联成键,从而实现官能团化。其中,催化性能优异的催化剂除了贵重金属铑、钯和钌等的配合物之外,还有普通金属,如铁、镍、铜和钴的盐及其配合物。这些方法拓展了烯烃官能团化的研究领域,为有机合成工作者提供新方法和思路,还为将来的产业化生产提供新方案。 相似文献
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The diastereoselective hydrogenation catalyzed by heterogeneous metallic catalysts uses a covalently bound chiral auxiliary to induce the chirality. It remains an active synthetic methodology in the asymmetric synthesis of chiral products and may proceed with high diastereoselectivity. This review describes recent examples using this method, such as hydrogenation of C=C, C=O, and C=N bonds. The use of a chiral auxiliary group has also been successfully applied to the hydrogenation of aromatic and heteroaromatic rings. The choice of the chiral auxiliary was found to play a key role in the asymmetric hydrogenation. The results could be explained in terms of steric effect, with a preferred conformation of the adduct substrate and the addition occurring from the less bulky side. The catalytic metal, the support and the presence of additives were also found to have a significant influence. 相似文献
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Min Qiu Xiang‐Ping Hu Dao‐Yong Wang Jun Deng Jia‐Di Huang Sai‐Bo Yu Zheng‐Chao Duan Zhuo Zheng 《Advanced Synthesis \u0026amp; Catalysis》2008,350(9):1413-1418
We have recently reported a new chiral 1,2,3,4‐tetrahydro‐1‐naphthylamine‐derived phosphine‐phosphoramidite ligand, (Rc,Ra)‐THNAPhos, that is highly efficient in the rhodium‐catalyzed asymmetric hydrogenation of a broad range of α‐enol ester phosphonates. To further demonstrate the utility of THNAPhos in asymmetric hydrogenation, in this paper, we describe its new application in the asymmetric hydrogenation of α‐dehydroamino acid esters, enamides, dimethyl itaconate and α‐enamido phosphonates. The results disclosed that the Rh/(Rc,Ra)‐THNAPhos complex is highly effective for the enantioselective hydrogenation of these kinds of functionalized CC olefins, affording the corresponding hydrogenation product in excellent enantioselectivities (normally over 99% ee). 相似文献
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泛解酸内酯是合成D-泛酸钙和D-泛醇的重要中间体,国内主要采用生物拆分法,虽取得一定进展,但存在底物浓度偏低、反应条件苛刻、光学纯度不高和催化剂活性不强等问题。化学不对称合成法成为近年来制备手性泛内酯的研究热点。根据手性源的不同,介绍过渡金属配合物催化不对称还原酮基泛内酯,过渡金属配合物催化羟醛缩合反应,有机小分子及其衍生物不对称催化羟醛缩合反应并经还原内酯化合成泛内酯以及光学活性化合物作为反应底物或非手性底物中加入手性助剂的合成手性泛内酯工艺。其中,有机小分子催化乙醛酸酯与醛的反应表现出良好的催化效果,且催化剂易得,反应条件温和,操作简单。缩合产物的收率和对映选择性均不高,设计具有高活性和高选择性的有机小分子手性催化剂是今后研究的重点。 相似文献
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Mercedes Coll Oscar Pmies Montserrat Diguez 《Advanced Synthesis \u0026amp; Catalysis》2013,355(1):143-160
A highly modular furanoside thioether‐phosphite/phosphinite/phosphine ligand library has been synthesized for the iridium‐catalyzed asymmetric hydrogenation of minimally functionalized olefins. These ligands can be prepared efficiently from easily accessible D ‐(+)‐xylose. We found that their effectiveness at transferring the chiral information in the product can be tuned by correctly choosing the ligand components. Enantioselectivities were therefore excellent (ees up to 99%) in a wide range of E‐ and Z‐trisubstituted alkenes using 5‐deoxyribofuranoside thioether‐phosphite ligands. It should be pointed out that these catalysts are also very tolerant to the presence of a neighbouring polar group. For 1,1‐disubstituted substrates, both enantiomers of the hydrogenation product can be obtained in high enantioselectivities simply by changing the configuration of the biaryl phosphite moiety. The asymmetric hydrogenation was also performed using propylene carbonate as solvent, which allowed the iridium catalysts to be reused while maintaining the excellent enantioselectivities. 相似文献
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[(Bisphosphine) RuCl 2 (1,2-diamine)] complexes are powerful catalysts in the asymmetric hydrogenation of unfunctionalized ketones. We sought to expand the scope and applicability of these complexes by exploring changes to the diamine structural motif. Via introduction of 1,3- and 1,4-diamines, the catalytic activity was significantly altered such that new classes of ketones could be considered for [(bisphosphine) RuCl 2 (diamine)] asymmetric hydrogenation. 相似文献