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将苯乙胺衍生的手性膦-亚磷酰胺酯配体应用在Rh-催化α-烯醇酯膦酸酯的不对称氢化反应中,考察了配体结构及反应条件对反应结果的影响,并在优化的条件下研究了各种底物的适用范围,产物的对映选择性最高>99%ee. 相似文献
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Dendrimersarehighlybranchedmacromoleculesthathavepreciselydefinedmolecularstructureswithnano scalesize .SincethepioneeringworkofvanKotenetal.reportedin 1994 ,1dendriticcatalystshavebecomeasub jectofintensiveresearch .2 ,3 Althoughanumberofden driticcatalystsha… 相似文献
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金鸡纳生物碱衍生手性双胺配体的合成及其在不对称氢转移反应中的催化作用 总被引:1,自引:0,他引:1
以价廉易得的天然金鸡纳生物碱奎宁和辛可宁为原料,在温和条件下容易地合成了6种手性双胺配体. 考察了它们与过渡金属Ir和Rh形成的配合物在苯乙酮不对称氢转移反应中的催化活性和不对称诱导作用. 结果表明, 9-氨基金鸡纳生物碱配体具有良好的不对称催化活性,而当配体中的氨基被取代后其对映选择性降低. 将9-氨基(9-脱氧)表辛可宁的Ir配合物用于其它芳香酮的不对称氢转移反应时,该配体也显示了很高的催化活性(80%~90%收率)和对映选择性(除对氯苯乙酮ee值为72%外,其余芳香酮ee值均为95%~97%). 相似文献
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Novel l -tartaric acid based stereodynamic biphenylbisphosphinite ligands with anilino linkers were prepared as cyclic diamide compounds. The influence of the constitutional substitution pattern of the amino group at the aniline moiety on the diastereoselective formation of the ligand was investigated. While the meta-anilino bridged ligands showed a highly dynamic behavior and no discrimination between (Rax) and (Sax) configuration, l -tartaric acid substitution on ortho-anilino bridged ligands leads to diastereoselective self-alignment of the central biphenol axis, which controls the stereoselectivity of the ligand and catalyst. The experimental findings were corroborated by theoretical calculations. In the rhodium-catalyzed enantioselective hydrogenation of methyl 2-acetamidoacrylate (MAA), an enantiomeric ratio of 75 : 25 (R/S) was obtained for the ortho-substituted ligand. 相似文献
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Lanning Li Bin Chen Yuanyuan Ke Qing Li Yue Zhuang Kun Duan Yichun Huang Dr. Jiyan Pang Prof. Dr. Liqin Qiu 《化学:亚洲杂志》2013,8(9):2167-2174
A valuable class of new heterocyclic and alicyclic prochiral α‐aminomethylacrylates has been conveniently synthesized through a three‐step transformation involving a Baylis–Hillman reaction, O‐acetylation, and a subsequent allylic amination. The corresponding novel β2‐amino acid derivatives were prepared with excellent enantioselectivities and high yields by catalytic asymmetric hydrogenation using the catalyst rhodium(Et‐Duphos) (Et‐Duphos=2′,5′,2′′,5′′‐tetraethyl‐1,2‐bis(phospholanyl)benzene)) under mild reaction conditions (up to 99 % ee and S/C=1000). The influence of the substrate on the enantioselectivity and reactivity is investigated, and the most suitable substrate configuration for the highly efficient enantioselective hydrogenation of β‐substituted α‐aminomethylacrylates under the Rh–Duphos system is reported. The current protocol provides a very practical, facile, and scalable method for the preparation of heterocyclic and alicyclic β2‐amino acids and their derivatives. 相似文献
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手性磷-烯配体在不对称催化反应中的应用近年来受到化学家们的关注,已经成为一个热门的研究领域.磷-烯配体作为一类新兴杂化烯烃配体,将具有强配位能力的磷原子与配位方式特殊但配位能力相对较弱的碳-碳双键结合在一起,兼具了部分手性膦配体和手性双烯配体的优点,在一些过渡金属如铑、钯、铱等催化的不对称反应中表现出独特的催化性能,不但能高效催化反应,而且能取得优异的对映选择性.本文综述了自2004年首例磷-烯配体的合成及应用报道以来该领域的研究进展,对过去十几年中发展的各种手性磷-烯配体的结构特征、合成方法以及它们在不同催化不对称反应中的应用进行了分类概括,期望为未来进一步拓展手性烯烃配体的类型和应用提供思考和方向. 相似文献
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Chloride‐Bridged Dinuclear Rhodium(III) Complexes Bearing Chiral Diphosphine Ligands: Catalyst Precursors for Asymmetric Hydrogenation of Simple Olefins 下载免费PDF全文
Dr. Yusuke Kita Shoji Hida Kenya Higashihara Dr. Himanshu Sekhar Jena Kosuke Higashida Prof. Dr. Kazushi Mashima 《Angewandte Chemie (International ed. in English)》2016,55(29):8299-8303
Efficient rhodium(III) catalysts were developed for asymmetric hydrogenation of simple olefins. A new series of chloride‐bridged dinuclear rhodium(III) complexes 1 were synthesized from the rhodium(I) precursor [RhCl(cod)]2, chiral diphosphine ligands, and hydrochloric acid. Complexes from the series acted as efficient catalysts for asymmetric hydrogenation of (E)‐prop‐1‐ene‐1,2‐diyldibenzene and its derivatives without any directing groups, in sharp contrast to widely used rhodium(I) catalytic systems that require a directing group for high enantioselectivity. The catalytic system was applied to asymmetric hydrogenation of allylic alcohols, alkenylboranes, and unsaturated cyclic sulfones. Control experiments support the superiority of dinuclear rhodium(III) complexes 1 over typical rhodium(I) catalytic systems. 相似文献
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Jędrzej Wysocki Dr. Nuria Ortega Prof. Dr. Frank Glorius 《Angewandte Chemie (International ed. in English)》2014,53(33):8751-8755
An enantioselective hydrogenation of disubstituted furans has been developed by using a chiral ruthenium catalyst with N‐heterocyclic carbene ligands. This reaction converts furans into valuable enantioenriched disubstituted tetrahydrofurans. 相似文献
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Fabian Brüning Dr. Haruki Nagae Daniel Käch Prof. Dr. Kazushi Mashima Prof. Dr. Antonio Togni 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(46):10818-10822
The asymmetric hydrogenation of 2,2,2-trifluoroacetophenones and aryl perfluoroalkyl ketones was developed using a unique, well-defined chloride-bridged dinuclear rhodium(III) complex bearing Josiphos-type diphosphine ligands. These complexes were prepared from [RhCl(cod)]2, Josiphos ligands, and hydrochloric acid. As catalyst precursors, they allow for the efficient and enantioselective synthesis (up to 99 % ee) of chiral secondary alcohols with perfluoroalkyl groups. This system does not require an activating base for the hydrogenation of 2,2,2-trifluoroacetophenones. Additionally, the enantioselective C=O hydrogenations of 2-phenyl-3-(haloacetyl)-indoles, a class of privileged structures in medicinal chemistry, is reported for the first time. 相似文献
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Chiral S,P-donor ferrocene-derived ligands were synthesized and applied in the asymmetric hydrogenation of quinolines using the [Ir(COD)Cl]2/S,P-ligand complex as the catalyst in the presence of iodine. The effects of the solvent and hydrogen pressure on conversion and enantioselectivity were examined, and up to 82% ee was obtained. The planar chirality plays an important role in this reaction. R- and S-enantiomers of 1,2,3,4-tetrahydroquinoline derivatives were obtained using ligands 3 and 5, respectively. 相似文献
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Prof. Ryoichi Kuwano Yuta Hashiguchi Ryuhei Ikeda Dr. Kentaro Ishizuka 《Angewandte Chemie (International ed. in English)》2015,54(8):2393-2396
The asymmetric hydrogenation of pyrimidines proceeded with high enantioselectivity (up to 99 % ee) using an iridium catalyst composed of [IrCl(cod)]2, a ferrocene‐containing chiral diphosphine ligand (Josiphos), iodine, and Yb(OTf)3 (cod=1,5‐cyclooctadiene). The chiral catalyst converted various 4‐substituted pyrimidines into chiral 1,4,5,6‐tetrahydropyrimidines in high yield. The lanthanide triflate is crucial for achieving the high enantioselectivity as well as for activating the heteroarene substrate. 相似文献
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以(1S,2S)-(+)-1,2-二苯基乙二胺为原料,分别与2-噻唑甲醛和4-咪唑甲醛经缩合反应合成了两个新型的四齿手性亚胺配体——N,N'-二(2-噻唑)-1,2-二苯基乙二胺(L1)和N,N'-二(4-咪唑)-1,2-二苯基乙二胺(L2),其结构经1H NMR,IR和ESI-MS表征。L1与Ir Cl(cod)2,L2与[Ir HCl2(cod)]2分别经原位反应制得催化剂CatⅠ和CatⅡ。以异丙醇为氢源,研究了CatⅠ和CatⅡ对苯乙酮经不对称氢转移反应合成手性α-苯乙醇的催化性能。结果表明:在最佳反应条件[苯乙酮0.5 mmol,n(KOH)∶n(Cat)=4∶1,异丙醇15 m L,于45℃反应10 h]下,CatⅠ为催化剂时,转化率90%,ee值33%;CatⅡ为催化剂时,转化率87%,ee值27%。 相似文献
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较系统地总结了用于不对称催化氢化反应的各类配体的特点及性能,对于每类配体的最新研究成果进行了较详细的评述。参考文献81篇。 相似文献
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将BoPhoz类膦-氨基膦配体应用在Rh-催化β-脱氢氨基酸酯的不对称氢化反应中,考察了配体结构及反应条件对反应结果的影响,并在优化的条件下研究了各种底物的适用范围,产物的对映选择性达81%ee. 相似文献