Tri-lacunary polyoxometalates of Na8H[PW9O34] as heterogeneous Lewis base catalysts for Knoevenagel condensation, cyanosilylation and the synthesis of benzoxazole derivatives
作者:Shen Zhao、Yang Chen、Yu-Fei Song
DOI:10.1016/j.apcata.2014.01.017
日期:2014.4
development of tri-lacunary polyoxometalates (POMs) of Na8H[A-PW9O34]·7H2O and Na8H[B-PW9O34]·19H2O (Na-A-PW9 and Na-B-PW9) as highlyselective and efficient heterogeneous Lewis base catalysts for Knoevenagel condensation, cyanosilylation of various aldehydes and ketones and the synthesis of benzoxazole derivatives at 25 °C under mild conditions. Since both Na-A-PW9 and Na-B-PW9 display no characteristic porosity
Classical Keggin Intercalated into Layered Double Hydroxides: Facile Preparation and Catalytic Efficiency in Knoevenagel Condensation Reactions
作者:Yueqing Jia、Yanjun Fang、Yingkui Zhang、Haralampos N. Miras、Yu-Fei Song
DOI:10.1002/chem.201501953
日期:2015.10.12
Knoevenagel condensationreactions of various aldehydes and ketones with Z‐CH2‐Z′ type substrates (ethyl cyanoacetate and malononitrile) at 60 °C in mixed solvents (V2‐propanol:Vwater=2:1) demonstrated highly efficient catalytic activity. The synergistic effect between the acidic and basic sites of the Mg3Al‐PW12 composite proved to be crucial for the efficiency of the condensationreactions. Additionally
Layered double hydroxide anchored ionic liquids as amphiphilic heterogeneous catalysts for the Knoevenagel condensation reaction
作者:Tengfei Li、Wei Zhang、Wei Chen、Haralampos N. Miras、Yu-Fei Song
DOI:10.1039/c7dt03665e
日期:——
attention has been dedicated to the development of heterogeneous base catalysts providing a green and sustainable process in benign aqueous media. Herein, the ionicliquid modified layered double hydroxide (LDH) based catalysts of LDH-IL-Cn (n = 4, 8, 12) were prepared by adopting an exfoliation/assembly strategy, in which the ionicliquids (ILs) were covalently anchored onto the surface of LDH layers. The
近年来,人们一直致力于开发在良性水性介质中提供绿色和可持续工艺的非均相碱催化剂。在此,通过采用剥落/组装策略制备了LDH-IL-C n(n = 4、8、12)的离子液体改性层状双氢氧化物(LDH)基催化剂,其中离子液体(ILs)是共价的固定在LDH层的表面上。通过FT-IR,固态13 C NMR,29 Si CP / MAS NMR,27 Al-MAS NMR,XRD,TG-DTA,BET,XPS,SEM,CO 2-表征所得的LDH-IL-C n。 TPD,接触角实验等。在室温下,LDH-IL-C12在H 2 O中对各种醛与氰基乙酸乙酯/丙二腈的Knoevenagel缩合反应的催化性能显示出优异的收率和选择性。而且,LDH-IL-C12的碱催化剂可以容易地再循环和再使用至少5次,而不会降低其催化效率。放大实验表明,该催化剂保留了其效率和坚固性。
Novel synthesis of highly functionalized cyclopentane derivatives via [3 + 2] cycloaddition reactions of donor–acceptor cyclopropanes and (<i>E</i>)-3-aryl-2-cyanoacrylates
作者:Chenlu Dai、Mingshuang Li、Mengjun Chen、Naili Luo、Cunde Wang
DOI:10.1177/1747519819831883
日期:2019.1
An efficient [3 + 2] cycloadditionreaction of cyanocyclopropanecarbonates and (E)-3-aryl-2-cyanoacrylates mediated by 1,8-diazabicyclo[5.4.0]undec-7-ene for the synthesis of highly functionalized cyclopentane derivatives in moderate to good yields (79%−87%) was developed. The structures of two typical products were confirmed by X-ray crystallography.
1,8-二氮杂双环[5.4.0]十一碳-7-烯介导的氰基环丙烷碳酸酯和(E)-3-芳基-2-氰基丙烯酸酯的有效[3+2]环加成反应,用于合成高度官能化的环戊烷衍生物开发了良好的产量 (79%−87%)。通过 X 射线晶体学证实了两种典型产物的结构。
Immobilization of L-Lysine on Zeolite 4A as an Organic-Inorganic Composite Basic Catalyst for Synthesis of α,β-Unsaturated Carbonyl Compounds under Mild Conditions
作者:Farzad Zamani、Mehdi Rezapour、Sahar Kianpour
DOI:10.5012/bkcs.2013.34.8.2367
日期:2013.8.20
(Lys) immobilized on zeolite 4A was prepared by a simple adsorption method. The physical and chemical properties of Lys/zeolite 4A were investigated by X-ray diffraction (XRD), FT-IR, Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV-vis. The obtained organic-inorganic composite was effectively employed as a heterogeneous basic catalyst for