共查询到19条相似文献,搜索用时 62 毫秒
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Birch还原反应产物为非共轭的烯烃,其原因在各种基础有机化学教材中都未有明确探讨。现有机理表明,决定产物双键位置的一步是芳香族化合物获得2个电子后形成的负离子中间体的质子化。基于量子化学计算与其他文献的报道对质子化的区域选择性做出了探讨。结论从定性与定量2方面指出,上述质子化的反应位点是中间体HOMO中轨道系数最大的碳原子,即该反应的区域选择性由动力学因素控制。 相似文献
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有机锡化合物催化合成应用进展 总被引:8,自引:1,他引:7
综述了近二十年来有机锡化合物在催化合成中的应用进展,阐述了有机锡化合物在催化加成,酯化,环化,偶联,聚合等方面的应用,有机锡化合物催化反应条件温和,活性高,有很高选择性,在催化合成领域有广阔的应用前景。 相似文献
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有机硒化物的反应及其在天然产物合成中的应用 总被引:2,自引:0,他引:2
有机硒化合物在有机合成,尤其是在天然产物的合成中,有着广泛而独特的应用。近年还发现,有些硒化合物本身就具有抗癌、抗病毒、防衰老等生理活性。因此,引起许多有机化学、生物化学和药物化学工作者的极大兴趣。有机硒化物这些重要价值,是由它的化学 相似文献
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有机锡化合物在天然产物合成中的应用 总被引:5,自引:0,他引:5
综述了有机锡化合物在不同对称合成天然产物中的应用。有机锡化合物应用于天然产物的不对称合成,反应条件温和、活性高,有很高的立体选择性和区域选择性,有广阔的应用前景。 相似文献
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光化学合成在有机合成化学,特别在一些非常见结构的合成中占有特殊的地位,能大大缩短传统合成化学的步骤而经济实用.本文主要以天然产物及其中间体的合成,举例介绍有机合成光化学及其研究现状. 相似文献
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可见光促进的光氧化还原催化在近年来取得了重要进展, 许多可见光光氧化还原的反应被用于复杂分子的构建. 本文概述了这一领域的最新成果, 重点介绍该策略作为关键步骤在天然产物及类天然产物化合物的全合成中的应用. 相似文献
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碱金属/液氨溶液具有很强还原性,在有机合成中有着广泛的运用。在高等教育出版社出版的由邢其毅、裴伟伟、徐瑞秋以及裴坚等人编著的《基础有机化学》(第3版)中描述了在碱金属/液氨作用条件下的两类还原反应:炔烃被还原为烯烃的反应和Birch还原反应。一般认为这两种反应均生成了自由基负离子中间体。本文结合近几年的文献报道,对它们的机理进行进一步的探讨。 相似文献
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报导了用环戊二烯作原料合成了(iridoids)和9-异氰(9-isocyanopupukeanane)的路线。 相似文献
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The intramolecular Wittig Reaction has been applied to the synthesis of sec-butyl perfluorobutynoate. the saponification of the product with aqueous sodium hudroxide gave 3-sec-butoxy-4, 4, 4-trifluoro-(2) butenoic acid and 4, 4, 4-trifluoro-3-oxobutyric acid in 1:5 ration. 相似文献
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Recent advances in the synthetic applications of the oxazaborolidine-mediated asymmetric reduction 总被引:1,自引:0,他引:1
Byung Tae Cho Author Vitae 《Tetrahedron》2006,62(33):7621-7643
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Pavel Kukula 《Tetrahedron letters》2007,48(32):5657-5659
A molecular rearrangement observed during the Birch reduction of dibenzothiophene and 4,6-dimethyl-dibenzothiophene was explored and a mechanism for the rearrangement has been proposed. 相似文献
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With the aid of proposals from a computer program for synthesis design, a new method of synthesizing azaspiranes has been developed. In this method, one starts with a suitable benzoic acid ester, which is subjected to Birch reduction. Then the anionic intermediate is alkylated with 1,2-dibromoethane. The product is subsequently reacted with an amine to give a spiro lactam. 相似文献
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Recent advances in synthetic methods have led to the preparation of a wide array of transition metal phosphide nanoparticles, and characterization of these materials has provided insight into nanoscale magnetic and catalytic properties. This review highlights advances in the field that have been made since the time of the last review [S.L. Brock, S.C. Perera, K.L. Stamm, Chem. Eur. J. 10(2004)3364–3371]. Synthetic methods include solvothermal, solution-phase arrested precipitation, metal nanoparticle conversion, and phosphate reduction. Magnetic properties of FeP, Fe2P and MnP nanoparticles and nanorods (among others), and recent data on thiophene hydrodesulfurization catalyzed by discrete, unsupported Ni2P particles, is presented. Finally, the future prospects for the field are discussed. 相似文献
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Jianping JiangYee-Hing Lai 《Tetrahedron letters》2003,44(6):1271-1274
The Birch reduction of 10b,10c-dimethyl-10b,10c-dihydropyrene 1 and anthracene could be predicted on the basis of their reduction potentials and achieved readily with aqueous titanium trichloride in near quantitative yields. Controlled reduction of a nitro group could be achieved under these conditions with the aromatic hydrocarbon remaining intact. The anion derived from the hexane obtained from reduction of 1 provided synthetic routes to derivatives of 1 inaccessible from direct substitution reactions of 1. Oxidative dimerization of the anion led to the formation of a series of interesting products. 相似文献
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Na Na Yu Xia Zhenli Zhu Xinrong Zhang Prof. R. Graham Cooks Prof. 《Angewandte Chemie (International ed. in English)》2009,48(11):2017-2019
Selective and specific dihydrogenation of benzene and other arenes has been observed in a low‐temperature helium plasma. A surface Birch reduction mechanism has been proposed in which benzene molecules adsorbed on the discharge surface capture low‐energy surface‐adsorbed electrons and subsequently undergo protonation (see picture). Gas‐phase oxidation processes accompany the reduction reaction.