共查询到20条相似文献,搜索用时 62 毫秒
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1,1-二卤代-1-烯烃是有机化学中常见的合成片断,在合成化学中已得到了广泛的应用。该综述介绍了这一类化合物常见的制备方法以及反应的适用范围,并详细讨论了该类化合物在有机合成中的应用:(1)1,1-二卤代-1-烯烃在镁、有机锂、锌/溴化亚铜、二碘化钐、零价钯等金属或金属试剂作用下,发生α-消除反应生成烯基卡宾中间体的反应;(2)1,1-二卤代-1-烯烃在合成杂环以及核苷类似物等方面的应用。对于这类化合物在钯催化下的分子内(间)的偶联反应以及利用分子内的双环碳钯化反应,合成环状化合物等等方面的研究进展,也进行了详细的讨论。 相似文献
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一级芳胺广泛用于天然产物、药物、高分子和材料的合成中,传统合成一级芳胺是在高温、高压和封闭容器中采用钯催化卤代芳烃与氨气反应来制备,也可以在钯催化下使用氨的替代物,如Li[N(SiMe3)2],Zn[N(SiMes)2]与卤代芳烃反应来合成.显然,这些方法有以下缺点:(a)由于采用钯催化剂和复杂的配体,成本较高、毒性较大;(b)当使用氨气作为氨基源时,高温、高压和封闭容器是必不可少的;(c)当使用氨的替代物作为氨基源时,由于这些氨的替代物不易制备、成本也就较高.清华大学化学系付华课题组建立了一种合成一级芳胺的新方法. 相似文献
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双官能团醇类化合物催化胺化反应的研究进展 总被引:4,自引:0,他引:4
本文综述了由双官能团醇类化合物催化胺化合成二元胺或环胺的研究进展,分别讨论了金属催化剂和固体酸催化剂对双官能团醇类化合物的不同作用机制,考察了反应物结构对 反应活性和选择性的影响,重点介绍了超临界氨流体在二元醇催化胺化反应中的应用,并指出了今后研究的方向. 相似文献
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Vladimir I. Nedel'Kin 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):409-410
Synthesis, X-ray structure, ring-opening polymerization macrocyclic phenylene sulfides and their role in chemistry and technology of polyarylene sulfides are discussed. 相似文献
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A class of chiral ketone was synthesized for asymmetric epoxidation. High ee values have been obtained for a number of cis olefin and trans olefin. The epoxidation was stereospecific with no isomerizatiom observed in the epoxidation of acyclic system. Encourageingly high ee value has also been obtained for a number of terminal olefins. Mechanistic studies show that electronic interactions play an important role in the stereodifferentiation. O O O O O O NBoc O O t-BuO2CH2CN O O O … 相似文献
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Vinay V. ThakurA. Sudalai 《Tetrahedron letters》2003,44(5):989-992
N-Bromoamides catalyze effectively the aziridination of electron-deficient as well as electron-rich olefins using chloramine-T (N-chloro-N-sodio-p-toluenesulfonamide) as a nitrogen source under ambient conditions to afford the corresponding aziridines in good to excellent yields. 相似文献
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Phenyltetrafluorotelluromethoxide fluorinates olefins to form 1,2-difluorides. The reaction with styrene afforded 1-fluoro-4-phenyl-1,2-dihydronaphthalene
as the main product.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 742–744, April, 1998 相似文献
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R. F. Talipov I. M. Safarov G. R. Talipova M. G. Safarov 《Reaction Kinetics and Catalysis Letters》1997,61(1):63-68
A mechanism for formation of hydrogenated furans in the reaction of α-olefins with formaldehyde is suggested. Based on kinetic
data, it involves the equilibrium addition of protonated formaldehyde to the olefin. 相似文献
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Ramazanov I. R. Djyachenko L. I. Ibragimov A. G. Dzhemilev U. M. 《Russian Chemical Bulletin》2002,51(5):833-835
The reactions of olefins with alkyl halides and Et3Al in the presence of catalytic amounts of Cp2TiCl2 were studied. Unbranched -olefins of the aliphatic series underwent hydroalkylation under the action of tert-butyl bromide to form 2,3-dimethylalkanes. 相似文献
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过氧化氢为氧源催化烯烃环氧化研究 总被引:2,自引:0,他引:2
环境友好催化烯烃环氧化是催化氧化领域中的一大热点,过氧化氢作为一种理想的清洁氧源日益受到人们的重视。本文从匀相和多相催化两方面综述了近年来以过氧化氢为氧源催化烯烃环氧化研究的主要进展,对一些有很好工业化应用前景的反应体系作了详细介绍。 相似文献
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I. Wlassics 《Journal of fluorine chemistry》2004,125(10):1519-1528
The second order 2π + 2π homo- and co-dimerization between various classes of fluorinated olefins has been investigated. The fluorinated olefins examined in this study were: (1) RfOCFCF2 (perfluorinated vinyl ethers); (2) RfCFCF2 (perfluorinated terminal olefins); (3) RCH2CFCF2; (4) PhOCFCF2 (aryl perfluorinated vinyl ethers).Homo-dimerizations between vinyl ethers have an Ea between 20 and 24 kcal mol−1 while homo-dimerizations between terminal olefins have an average Ea between 35 and 40 kcal mol−1; vinyl groups have a second order cyclodimerization rate constant of formation between 1 × 10−7 and 1 × 10−4 M−1 S−1 while vinyl ethers have a second order cyclodimerization rate constant of formation = 1 × 10−1 M−1 s−1. If there is a CH2 group α to the terminal olefin, the Ea of cyclodimerization is about 7 kcal mol−1) lower with respect to those olefins with a CF2 α to the instauration. At 270 °C co-dimerizations have an average ΔS≠ = −45 cal K−1 mol−1 and a second order rate constant of cyclodimerization ranging between 0.1 × 10−4 M−1 S−1 and 16 × 10−4 M−1 S−1 while homo-dimerizations have an average ΔS≠ = −17 cal K−1 mol−1 and a second order rate constant which can span from 7 × 10−7 M−1 S−1 to as much as 1 × 10−1 M−1 S−1 depending on the electronic nature of the perfluorinated terminal olefin.A good correlation between the electronegativity χ and the activation energy Ea demonstrates that “polarizing” groups, O, PhO, α to the olefin play an important role in the formation and stabilization of the cyclodimerization biradical intermediate. 相似文献
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《中国化学快报》1998,(5)
Muchattentionhasrecentlybeenpaidtophotoassisted0rganicsynthesiswithhighyieldsandselectivitiesl'2.Theincreasingnumberofpapershaveshownthatthereisasubstantialinterestintheapplication0fph0t0chemicaltechniquestoh0mogeneouscatalysis.Well-knownexamples,whichshowthatlightcaninitiateandacceleratecatalyticreacti0ns,includephotocatalyzed0lefinisomerization',methoxycarb0nylati0n',andfunctiona-lizationoftheC-Hbondofalkanes5'6.Itiskn0wnthatmeth0xycarb0nylationofolefinsisanimp0rtantchemicalprocess,butitsap… 相似文献