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我们对欧洲玉米螟性信息素的主要成份的合成方法进行了选择性的研究,欧洲玉米螟性信息素主要由顺-11-十四烯-1-醇乙酸酯(Ⅰ)和反式-11-十四烯-1-醇乙酸酯(Ⅱ)组成,不同地区的欧洲玉米螟性信息素所含的顺、反异构体比例有所不同,在欧洲及加拿大,这种害虫性信息素顺、反异构体比例是97:3。 相似文献
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棉铃虫(Heliothis amigora)是世界性棉花害虫,在我国产棉区的危害也甚为严重.棉铃虫性信息素主要组份为顺-9-十六碳烯醛-1(1)和顺-11-十六碳烯醛-1(2)等烯醛类化合物.1和2的合成报道是以 Wittig 反应为主或炔锂和卤代烷缩合,这种合成路线所得的1和2.其顺式双键的纯度均仅95~98%,总产率约35%.因为昆虫对信息素的几何异构体组成非常敏感.所以几何异构体的纯度在合成昆虫信息素中特别重要.为此我们选择了用顺-二(烯基)铜锂的烷基化反应合成1和2(图式1A).得到了>99.5%顺式构型的产物.用此法不仅合成步骤短,而且总产率高达80%.此外用本法还可通过变换图式1中的 m 或 n 数得到一系列双键位置不同的长链脂肪醛、醇及其乙酸酯的昆虫性信息素化合物.溴化物3和锂反应生成的锂试剂与碘化亚铜,乙炔及碘代烷通过一步反应即生成顺式烯化合物4,产率90%.然后除去4的保护基团和再经 PCO 氧化,得1和2,总产率分别为79.5% 相似文献
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J. Brossas C. P. Pinazzi F. Clouet 《Journal of polymer science. Part A, Polymer chemistry》1973,11(7):1517-1529
We have synthesized a series of alkadiene and dialcohol homologs of terpenoid natural products by using anion-radicals of isoprene and butadiene. The reactions of the two monomers were initiated anionically by use of alkali metal–aromatic hydrocarbon complexes. The polymerization was stopped at the dimer stage. This method constitutes a route of synthesis for numerous organic compounds, such as alcohols and hydrocarbons. 相似文献
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Yu. Yu. Titova L. B. Belykh G. V. Ratovskii A. V. Rokhin O. G. Soroka F. K. Schmidt 《Kinetics and Catalysis》2013,54(4):431-442
The effect of the composition of the catalytic systems based on Co(acac)2 and tertiary phosphines on the activity and efficiency of cobalt catalysts in the coupled hydrogenation of alkenes and arenes is reported. The process occurs in the presence of cobalt catalysts formed under the action of both organoaluminum compounds and tert-butoxy derivatives of complex aluminum hydrides. NMR and IR spectroscopic methods show that the interaction of the components of the catalytic systems yields mono- and/or trihydrido cobalt phosphine complexes, whose composition depends on the nature of the reducing agent and gas atmosphere. The homogeneous character of the process is hypothesized. The most probable schemes are proposed for the reaction mechanism, according to which the kinetic coupling of alkene (alkadiene) and arene hydrogenations is due to the fact that the reaction proceeds through a σ-alkyl or σ-alkenyl cobalt complex with two phosphorus-containing ligands. 相似文献
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催化裂化是石油化工的核心单元之一.从催化裂化尾气中分离出来的碳四馏分富含许多的不饱和烯烃,如1-丁烯、顺、反式-2-丁烯以及少量的1,3-丁二烯,这些不饱和烯烃可以通过后续聚合反应,生成合成橡胶和工程塑料的重要原料,具有重要的应用价值.上述工艺过程对原料中1,3-丁二烯的含量(<100~200 ppm)有严苛的要求.采用选择性加氢技术对碳四馏分中的1,3-丁二烯进行选择性加氢,将其转化为更高附加值的单烯烃是一个理想的解决方案.然而,1,3-丁二烯加氢反应得到的单烯烃可能发生深度加氢得到副产物丁烷.因此,开发高效选择性加氢催化剂对碳四资源的利用具有重要的现实意义.另一方面,1,3-丁二烯加氢反应可以作为模型反应,用来考察选择性加氢催化剂的性能.基于此,该反应无论在工业界还是学术界均受到广泛关注.尽管如此,有关1,3-丁二烯加氢催化剂研究进展方面的综述极少.仅有关于1,3-丁二烯加氢作为模型反应的综述报道.本文对过去半个世纪以来1,3-丁二烯加氢反应中不同催化剂的发展历程进行系统综述,特别是包括Pd,Pt和Au等的单一贵金属催化剂.重点介绍以下内容:(1)固体催化剂构效关系,包括活性金属尺寸效应、晶面和形貌效应以及载体效应(晶相、孔道和酸碱性);(2)高性能催化剂的设计新策略,如单原子催化剂、核壳结构催化剂、金属-离子液复合催化体系以及载体的形貌调控;(3)催化剂的反应机理和失活机理.提出了1,3-丁二烯选择性加氢高性能催化剂开发面临的挑战,并对潜在的发展方向进行了展望.本文认为随着纳米技术和金属纳米材料合成方法的快速发展,对贵金属活性组分进行原子层面上的调控(包括形貌、尺寸以及单原子配位环境等)已成为可能.这将有助于研制出一类新型高性能选择性加氢催化材料,从而实现高转化率条件下高附加值单烯烃的定向转化.此外,载体的酸碱性和孔道结构的调控有助于进一步调节催化剂的抗积炭性能,也是未来发展的一个重要方向. 相似文献
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A. A. Karapetyan R. A. Tamazyan A. R. Mikaelyan A. M. Grigoryan A. S. Vardanyan L. Zh. Nikogosyan 《Journal of Structural Chemistry》2008,49(5):965-968
Addition of trichloroacetonitrile to 2,5-dimethyl-1,5-hexadiene in the presence of cuprous amine complexes is studied. Single crystal X-ray diffraction unambiguously proves that the main product is a racemic mixture of the cyclic symmetric nitrile: (1r,3R,6S)-and (1r,3S,6R)-1,3,6-trichloro-3,6-dimethylcycloheptanecarbonitrile. Established relative configuration of the product confirms the ring closure mechanism suggested before. Also, a side product 2,5-dimethyl-2,5-dichlorohexane is isolated (the product of hydrochlorination of the starting alkadiene). Low-temperature (190 K) structural examination of this centrosymmetrical molecule indicates that the unit cell comprises one molecule. 相似文献
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催化裂化是石油化工的核心单元之一.从催化裂化尾气中分离出来的碳四馏分富含许多的不饱和烯烃,如1-丁烯、顺、反式-2-丁烯以及少量的1,3-丁二烯,这些不饱和烯烃可以通过后续聚合反应,生成合成橡胶和工程塑料的重要原料,具有重要的应用价值.上述工艺过程对原料中1,3-丁二烯的含量(<100~200 ppm)有严苛的要求.采用选择性加氢技术对碳四馏分中的1,3-丁二烯进行选择性加氢,将其转化为更高附加值的单烯烃是一个理想的解决方案.然而,1,3-丁二烯加氢反应得到的单烯烃可能发生深度加氢得到副产物丁烷.因此,开发高效选择性加氢催化剂对碳四资源的利用具有重要的现实意义.另一方面,1,3-丁二烯加氢反应可以作为模型反应,用来考察选择性加氢催化剂的性能.基于此,该反应无论在工业界还是学术界均受到广泛关注.尽管如此,有关1,3-丁二烯加氢催化剂研究进展方面的综述极少.仅有关于1,3-丁二烯加氢作为模型反应的综述报道.本文对过去半个世纪以来1,3-丁二烯加氢反应中不同催化剂的发展历程进行系统综述,特别是包括Pd,Pt和Au等的单一贵金属催化剂.重点介绍以下内容:(1)固体催化剂构效关系,包括活性金属尺寸效应、晶面和形貌效应以及载体效应(晶相、孔道和酸碱性);(2)高性能催化剂的设计新策略,如单原子催化剂、核壳结构催化剂、金属-离子液复合催化体系以及载体的形貌调控;(3)催化剂的反应机理和失活机理.提出了1,3-丁二烯选择性加氢高性能催化剂开发面临的挑战,并对潜在的发展方向进行了展望.本文认为随着纳米技术和金属纳米材料合成方法的快速发展,对贵金属活性组分进行原子层面上的调控(包括形貌、尺寸以及单原子配位环境等)已成为可能.这将有助于研制出一类新型高性能选择性加氢催化材料,从而实现高转化率条件下高附加值单烯烃的定向转化.此外,载体的酸碱性和孔道结构的调控有助于进一步调节催化剂的抗积炭性能,也是未来发展的一个重要方向. 相似文献
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V. K. Brel 《Russian Journal of Organic Chemistry》2016,52(12):1804-1811
Methods have been developed for functionalizing the alkaloid cytisine via introduction of alka-1,3- and -2,3-dien-2-ylphosphonate fragments. The main pathway of the reaction of cytisine with 2-(diethoxyphosphoryl) alka-2,3-dien-1-yl methanesulfonates is nucleophilic substitution of the methanesulfonyloxy group with retention of the alkadiene skeleton. A minor reaction pathway is nucleophilic substitution with formation of alka-1,3-dien-2-ylphosphonates. Cytisine conjugates with exclusively alka-1,3-dien-2-ylphosphonate fragment have been synthesized by copper(I)-catalyzed 1,3-dipolar cycloaddition of N-(prop-2-yn-1-yl)cytisine to 3-azidoalka-1,3-dien-2-ylphosphonates. 相似文献
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Herbert Lehmkuhl Anna Rufinska Reinhard Benn Gerhard Schroth Richard Mynott 《Journal of organometallic chemistry》1980,188(3):C36-C40
η5-Cyclopentadienyl-η1-η2-alk-4-enylnickel complexes has been prepared by treatment of nickelocene either with the appropriate alkenylmagnesium halide or with isopropylmagnesium bromide and an alkadiene. 1H and 13C NMR results indicate that the C=C bond is complxed to the nickel atom. The cyclopentadienylalk-3-enylnickel compounds do not isomerize to the corresponding cyclopentadienyl-η3-allylnickel complexes, if β-H-elimination is suppressed by substituting β-H by methyl. Cyclopentadienylalk-5-enylnickel compounds isomerize readily to the alk-4-enylnickel complexes. 相似文献
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《Journal of Analytical and Applied Pyrolysis》2006,75(1-2):344-352
An application of pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) is presented for the fast on-line testing of solid catalysts activity in upgrading pyrolysis oils and/or gases of natural and synthetic polymers. Evaluation of the chemical conversion by a catalyst is simply and quickly performed in a Py-GC/MS instrument without any modification either of the micropyrolyser or the GC inlet. The pyrolysis products evolved from the sample pass through catalyst microbeds of some mm length and the GC/MS analysis of the converted products is performed on-line. Modification of polyolefin, styrene copolymer, polyester, polyamide, brominated epoxy resin and wood pyrolysate was carried out applying sodium type zeolite and medium acidic mesoporous aluminosilicate in the microbeds. The primary pyrolysis products are converted over the microbeds due to the catalytic activity of the bed material. Intramolecular hydrogen transfer reactions promoted by Na zeolite results in the isomerisation of alkenes and alkadienes evolved by pyrolysis from polyethylene and polypropylene. These basic catalysts were found to be effective for the elimination of brominated phenols from the pyrolysate of brominated epoxy resin. Cracking of alkane and alkene oligomer products of polyolefins to light isoalkenes occur over acidic mesoporous aluminosilicate. Certain compounds with polar groups evolved from polyester, polyamide, cellulose or lignin are removed by this catalyst. Alkenylaromatic compounds are simultaneously hydrogenated and polyaromatised in pyrolysis oils of styrene copolymers over both acidic and basic aluminosilicate catalysts tested. 相似文献
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The design, synthesis, properties and molecular modeling of fully conjugated dendritic molecules and conjugated hyperbranched polymers are described. It has been shown that conjugated hyperbranched molecules are much more soluble than their linear analogues while maintaining all the properties characteristic of conjugated polymers. It was found that the use of polymeric solid support in hyperbranched polymerization allows to control molecular weight and degree of branching (DB). The molecular modeling of hyperbranched conjugated molecules reveals that hyperbranched structure of conjugated molecules affects significantly neither their stability nor the conjugation. On the other hand the terminal groups affect appreciably the electronic structure of conjugated hyperbranched molecules. 相似文献
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假尿嘧啶核苷结合抗原的制备*李瑜闫书一(成都理工学院应用化学系,成都610059)王科太谢家理庞友印**(四川联合大学化学系,成都610064)关键词假尿嘧啶核苷抗原抗体根据细胞的分子生物学原理和临床研究确认,假尿嘧啶核苷(ψ)可作为某些肿瘤的标志物... 相似文献