共查询到20条相似文献,搜索用时 93 毫秒
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Cu(Ⅰ)催化的炔烃与叠氮的Huisgen 1,3-偶极环加成反应(CuAAC)可用于构建三唑环,该反应条件温和,产物专一,被认为是“点击化学”的精髓,并广泛应用于医药、生物有机及材料化学等多个领域.CuSO4/抗坏血酸钠体系是该反应最常用的催化方法,但近年来,大量更高效的催化体系被成功开发以解决当前催化体系中存在的问题,例如,外加配体的使用可以明显加快反应速率,从而降低催化剂用量和缩短反应时间,这归因于配体参与配位可以更好地稳定Cu(Ⅰ)催化中心.目前应用于该反应体系的配体大多为对称型多齿氮配体,例如三三唑甲胺衍生物(TBTA)等.我们开发了两类含有吡唑、苯并咪唑等基团的非对称型多齿氮配体及其应用,发现这类配体除了具有稳定金属中心的作用外,还因有吡唑或苯并咪唑等基团的存在,所形成的配合物往往比那些包含对称型配体的配合物表现出更高的催化活性.本文合成了一类含有非对称型配体的铜配合物.将铜前体Cu(CH3CN)4PF6与非对称型多齿氮配体二吡啶甲基吡唑甲基胺(HNpy2pz)在甲醇中反应,由于配体结构中吡唑NH基团的存在,反应在最终脱除一分子H2O后,意外获得了一种双核结构的铜配合物,其分子结构通过X射线单晶衍射成功表征.受到两个金属中心协同效应的影响,双核配合物催化剂往往能表现出比单核配合物更优异的催化性能,因此,我们进一步考察了该双核配合物催化CuAAC反应的活性.结果表明,在催化剂用量低至0.1-0.3 mol%的情况下,22种炔烃和叠氮在25℃反应16h均能得到单一的1,4-二取代三唑产物,分离收率在95%以上,且抗坏血酸钠还原剂用量仅需1-3 mol%,说明受到配体的影响,催化剂的稳定性非常好.这是目前该反应成功开发出的几个高效双核催化剂之一. 相似文献
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合成了两种单体双酚A二炔丙基醚与4,4′联苯二苄叠氮,研究了一种新的低温聚合体系———双酚A二炔丙基醚与4,4′联苯二苄叠氮在烘箱中的本体聚合行为.通过红外、核磁共振以及质谱、元素分析等表征了单体的结构.利用傅立叶红外技术(FTIR)跟踪了聚合反应过程中特征基团的变化,采用差示扫描量热技术(DSC)研究了聚合反应工艺及其动力学,热失重分析(TGA)考察了聚合产物的热稳定性能.通过Kissinger法和0zawa法获得了反应的一些动力学参数.结果表明,双酚A二炔丙基醚与4,4′联苯二苄叠氮易发生1,3偶极环加成聚合反应,在聚合物结构中形成三唑五元环,它们的聚合起始温度在70℃左右,聚合反应的主反应是一级反应,表观活化能ΔE=84.6kJmol,指前因子A=4.865×1010min-1.同时发现,聚合物具有较好的热稳定性能. 相似文献
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从豆甾醇出发,通过10步反应,合成得到具有显著细胞毒活性的24-亚甲基胆甾-5-烯-3β,19-二醇(1),总产率为16%.目标产物1的熔点、[α]值和波谱数据与天然产物一致.化合物1的合成是首次报道,它对人体鼻咽癌(CN2)和胃癌(Mgc803)细胞有显著抑制活性. 相似文献
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Shao Ning WANG Ying Kun QIU Hui XU Yi Hui DENG Da Wei CHEN 《中国化学快报》2006,17(2):173-176
Mammalian hepatocytes (parenchymal cells) exclusively possess large number ofasialoglycoprotein receptors (ASGPr), which can recognize terminal D-galactose orN-acetylgalactosamine residues. Lactobionic acid 1, bearing a galactosyl group, isusually used as… 相似文献
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In the past few decades, much attention has been focused on palladium-catalyzed carbonylative reactions[1,2], which is a simple method to synthesize some complicated compounds[3,4]. This kind of reactions, however, can be carried out only when the substrates are arylhalide, heteroaryl halide, alkene halide,aryltrifluoromethyl-sulfonate and hypervalent iodonium salt[5] etc. Herein, we report a palladium-catalyzed carbonylative reaction between 3,7-bis(N,N-dimethylamino)-10H-dibenz[b,e] iodinium iodide(1)[6] with alcohols (2) at ambient temperature as shown in scheme. 相似文献
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《结构化学》2020,39(10):1892-1897
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LiXinZHANG GuiZhiLI ZhiQiangLI 《中国化学快报》2004,15(8):954-956
A novel heterocyclic hexacoordinate organotin(Ⅳ) complex, bis(O-vanillin)-semi ethylenediamino dibenzyltin (VEDBT) was synthesized by the reaction of dibenzyltin dichloride with bis(O-vanillin)-semiethyenediamine, its structure has been characterized by spectral methods.The electrodes using VEDBT as a neutral carrier show high selectivity for salicvlate anions. 相似文献
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Yong ZHANG Ke Li ZHANG* Man Ke JIA Hao TANG Ju Tang SUN Liang Jie YUAN College of Chemistry Molecular science Department of Chemistry Wuhan University Wuhan 《中国化学快报》2002,13(6):587-588
In recent years, the research on rare earth became a focus, and a lot of rare earth complex compounds with AB2O4 stoichiometry were prepared1-3. The compound SnDy2O4 is expected to spinel-type phase while it exhibits a new structure type. SnDy2O4 was prepared by the thermal decomposition of the oxalate precursor that was prepared by rheological phase reaction method. SnO(AR), Dy2O3(99.9%) and H2C2O4·2H2O are ground in molar ratio 1:1:4.1, and placed into the reaction apparatus. … 相似文献
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Shiyong Huo Yueqing Li Chaoyan Liang Jihong Liu Weijie Zhao 《Journal of carbohydrate chemistry》2013,32(2):75-84
The nucleophilic substitution reaction of carbohydrate imidazole-1-sulfonates with pyrrole and other nitrogen heterocyclic compounds is reported for the first time. Several novel N-carbohydrate-derived heterocyclic compounds have been prepared by this displacement reaction. The desired carbon-nitrogen bond formation proceeds under mild conditions to generate the coupling products in good yields with readily available and inexpensive reagents. This method is particularly suitable for carbohydrate imidazole-1-sulfonates of primary alcohols. Supplemental materials are available for this article. Go to the publisher's online edition of Journal of Carbohydrate Chemistry to view the free supplemental file. 相似文献
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Thealgaeproducedmanyinterestingpharmacologicalandbiologicalactivitymetabolitessuchasantibacterium.antineoplastic.anticancerandantimicrobialactivitiescompound'-'.Moreandmorechemistandbiologistpayattentiontothecollstituentsofthealgae.ThealgaSal'gassunl1)achedcollectedfromtheSouthChinaSeahasbeenstudiedandcompoundIwasisolated.FigureI-shestructureof1Theethanole\tractofalgaSul'gassll))]1)uk'hel/waselutedb}'silicagelusingpetroleunletherx"itllincreasingamountsofethy'lacetateaseluent.Thefractionobt… 相似文献
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GuangFeiLIU LangLIU DianZengJIA KaiBeiYU 《中国化学快报》2003,14(12):1230-1232
A new photochromic compound containing pyrazolone-ring was synthesized, and its crystal structure was determined on X-ray singlecrystal diffraction, which belongs to monoclinic crystal system, space group P21/c. The UV spectrum of the compound is studied. 相似文献