共查询到20条相似文献,搜索用时 140 毫秒
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介绍了近几年来酶的催化多功能性及其应用于有机合成反应研究的最新进展. 包括酶催化多功能性的几种主要类型和相应催化多功能性在Michael加成、Markovnikov加成、羟醛缩合反应、氧化反应及串联反应中的应用. 相似文献
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单烯烃与硼烷的硼氢化反应及相关反应 ,已经研究得很多 ,各教学参考书中均有讨论。然而二烯烃尤其是共轭二烯烃的硼氢化反应并不常见。在高等教育出版社出版的高等师范专科学校教材《有机化学》[1] 中有一道习题 : CH212 (BH3 ) 2 ? H2 O2OH- ?这是一道关于共轭二烯烃与硼烷反应的题目。反应怎样进行 ?是发生 1 ,4 加成还是只与其中一个双键加成或者与两个双键同时加成 ?历届学生都对此感到困惑。笔者为此查阅了一些相关书籍和文献 ,对二烯烃硼氢化反应的机理、影响因素及规律进行了较详细的论述 ,并据此给出习题的… 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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Wolfgang Oppolzer Victor Snieckus 《Angewandte Chemie (International ed. in English)》1978,17(7):476-486
Thermal cyclizations of appropriate dienes, enynes and related unsaturated systems, some of them carried out on an industrial scale, demonstrate increasingly the preparative power of the intramolecular ene reaction. A variety of substituted, fused and bridged ring systems, including natural products, are thus easily accessible in a regio- and stereo-selective manner. Numerous examples are discussed systematically illustrating the possibilities, limitations, and common features of this cyclization reaction and its reverse ring-opening process. 相似文献
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Ryan M. Bain Christopher J. Pulliam Fabien Thery Prof. R. Graham Cooks 《Angewandte Chemie (International ed. in English)》2016,55(35):10478-10482
Leidenfrost levitated droplets can be used to accelerate chemical reactions in processes that appear similar to reaction acceleration in charged microdroplets produced by electrospray ionization. Reaction acceleration in Leidenfrost droplets is demonstrated for a base‐catalyzed Claisen–Schmidt condensation, hydrazone formation from precharged and neutral ketones, and for the Katritzky pyrylium into pyridinium conversion under various reaction conditions. Comparisons with bulk reactions gave intermediate acceleration factors (2–50). By keeping the volume of the Leidenfrost droplets constant, it was shown that interfacial effects contribute to acceleration; this was confirmed by decreased reaction rates in the presence of a surfactant. The ability to multiplex Leidenfrost microreactors, to extract product into an immiscible solvent during reaction, and to use Leidenfrost droplets as reaction vessels to synthesize milligram quantities of product is also demonstrated. 相似文献
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Wolfgang Oppolzer 《Angewandte Chemie (International ed. in English)》1984,23(11):876-889
Rapidly accumulating evidence shows the value of asymmetric Diels-Alder and ene reactions for the syntheses of enantiomerically pure molecules. This article presents a systematic and critical treatment of various stereoface-differentiating principles, including very recent spectacular advances. The chiral information is mainly provided by covalently bound auxiliaries, some of which are crystalline, inexpensive, and readily available from naturally occurring monoterpenes, hydroxy acids, amino acids, steroids, and sugars. Non-destructive transfer of chirality leads to the efficient creation of up to four chiral centers with predictable relative and absolute configurations. Regenerative cleavage of the auxilary group from the diastereomerically pure adducts furnishes a range of polyfunctional, optically pure building blocks. Their synthetic potential is illustrated by strategic applications to the syntheses of physiologically interesting, chiral natural products such as prostaglandins, antibiotics, terpenoids, shikimic acid, alkaloids, and kainoids. 相似文献
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温度和时间对有机合成反应影响的探讨 总被引:1,自引:0,他引:1
根据物理化学和有机合成原理,从动力学、热力学、反应机理及溶解度等各方面详细分析了反应温度和反应时间对有机合成反应的影响。通过这些分析,可以让同学们更好地在合成反应课程的学习中掌握和分析反应温度和反应时间对反应的影响。 相似文献
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