共查询到18条相似文献,搜索用时 93 毫秒
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碳硼烷和碳硼炔金属配合物中的金属-碳键具有不同于经典金属-碳键的化学性质.一方面,二十面体碳硼烷独特的电子和空间效应使得碳硼烷金属配合物中的金属-碳键不参与和不饱和分子的反应 另一方面,在一定条件下具有大空间位阻的碳硼笼可以诱导某些碳-碳偶联反应.然而,碳硼炔金属配合物中的金属-碳键能与多种不饱和分子发生反应,其反应模式取决于中心金属离子的电子构型.本文简要总结了我们近期在这方面的研究进展. 相似文献
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结合可见光促进氧化还原和镍催化的碳碳键合成研究,是对过渡金属催化的交叉偶联反应的重要补充,具有广阔的发展空间和应用前景,是近年来有机光化学合成的前沿热点领域之一。本文依据反应设计的模式划分,小结目前该领域的研究进展。 相似文献
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迄今为止,贵金属(铑、钯、钌等)在过渡金属催化的碳碳键生成反应中发挥着主导作用,然而使用廉价金属催化剂更符合可持续发展的要求。锰是地壳中含量排第三位的过渡金属,价格便宜,环境危害性小,有潜力成为贵金属催化剂的替代品并发挥其自身独特的反应性。尽管锰参与的当量反应有大量文献报道,目前锰催化的反应尤其是碳碳键生成反应的发展还不成熟,如何实现高效的催化循环是锰催化领域面临的主要难题之一。本文对锰催化的付-克烷基化反应、格氏试剂的酰化反应、偶联反应、碳金属化反应、自由基反应和碳氢键活化反应进行了综述。 相似文献
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金属催化下芳基磺酸酯偶联反应的研究进展 总被引:1,自引:0,他引:1
综述了金属催化下芳基磺酸酯作为底物参与形成碳—碳键、碳—氮键的偶联反应, 如Suzuki-Miyaura反应、Sonogashira反应等方面的研究进展. 相似文献
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过渡金属催化(类)卤化物和不同金属试剂的交叉偶联反应是构建不同类型碳碳键和碳杂原子键的重要方法之一。该类反应一般使用活性较高的氯、溴、碘或类卤化物作为亲电试剂,尽管C—F键的键能较强,利用过渡金属直接活化较为惰性的芳基C—F键并参与实现的交叉偶联反应已有较多报道。此外,近期的研究表明,也可以通过直接活化烯基C—F键并催化实现该类底物参与不同类型的交叉偶联反应,从而进一步拓展了交叉偶联反应的底物适用范围,并应用于具有高附加值精细化学品的选择性合成。本文围绕钯或镍催化活化单氟或者多氟烯烃等底物参与的Negishi、Suzuki-Miyaura、Kumada、Hiyama和Sonogashira等5类交叉偶联反应,通过探讨已有方法的反应机理及其适用范围,综述了该领域的研究进展并进行了展望。 相似文献
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ZHANG Yu-Quan WANG Jin-Xian WANG Ke-Hu ZHAO Lian-Biao 《有机化学》2003,23(Z1):306-306
Cross-coupling processes of aryl or alkenyl halides with organometallic compounds of main group elements cat alyzed by palladium complexes have been found extensive use in organic synthesis. These cross-coupling reactions offer a powerful tool for the formation of carbon-carbon bonds. [1] The Suzuki-Miyaura cross-coupling reaction has been employed for the synthesis of ketone as well. 相似文献
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Among the fundamental transformations in the field of synthetic organic chemistry, transition-metal-catalyzed reactions provide some of the most attractive methodologies for the formation of C-C and C-heteroatom bonds. As a result, the application of these reactions has increased tremendously during the past decades and cross-coupling reactions became a standard tool for synthetic organic chemists. Furthermore, a tremendous upsurge in the development of new catalysts and ligands, as well as an increased understanding of the mechanisms, has contributed substantially to recent advances in the field. Traditionally, organic reactions are carried out by conductive heating with an external heat source (for example, an oil bath). However, the application of microwave irradiation is a steadily gaining field as an alternative heating mode since its dawn at the end of the last century. This tutorial review focuses on some of the recent developments in the field of cross-coupling reactions assisted by microwave irradiation. 相似文献
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Yong Guo Mei-Wei Huang Xiao-Lin Fu Chao Liu Qing-Yun Chen Zhi-Gang Zhao Ben-Zhong Zeng Jiong Chen 《中国化学快报》2017,28(4):719-728
This review summarizes the recent advances in the catalytic syntheses of CF_3S-containing organic molecules using various nucleophilic or electrophilic trifluoromethylthiolating reagents.C-halogen and C—H bonds in various molecules have been transformed to C—SCF_3 bonds by transition-metal-catalyzed reactions,such as cross-coupling of aryl halides.Enantioselective reactions controlled by chiral metal complexes or chiral organocatalysts have afforded many trifluoromethylthiolated chiral architectures,such as β-ketoesters and oxindoles.Very recently,visible-light-induced photoredox trifluoromethylthiolations have been developed,providing versatile CF_3S-containing structures efficiently. 相似文献
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The unique reactivity of hypervalent iodine reagents with Pd0 and PdII complexes has been exploited for a variety of synthetically useful organic transformations. For example, IIII reagents have been used in place of aryl halides for diverse Pd-catalyzed C-C and C-heteroatom bond-forming cross-coupling reactions. In addition, these reagents have found application in Pd-catalyzed oxidation reactions, including the oxidative functionalization of C-H bonds and the 1,2-aminooxygenation of olefinic substrates. This review discusses both the synthetic utility and the interesting mechanistic features of these transformations. 相似文献
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Cross-coupling reactions have become indispensable tools for creating carbon-carbon (or heteroatom) bonds in organic synthesis. Like in other important transition metal catalyzed reactions, such as metathesis, addition, and polymerization, unsaturated compounds are usually employed as substrates for cross-coupling reactions. However during the past decade, a great deal of effort has been devoted to the use of alkyl halides as saturated compounds in cross-coupling reactions, which has resulted in significant progress in this undeveloped area by introducing new effective ligands. Many useful catalytic systems are now available for synthetic transformations based on C(sp(3))-C(sp(3)), C(sp(3))-C(sp(2)) and C(sp(3))-C(sp) bond formation as complementary methods to conventional C(sp(2))-C(sp(2)), C(sp(2))-C(sp) and C(sp)-C(sp) coupling. This tutorial review summarizes recent advances in cross-coupling reactions of alkyl halides and pseudohalides catalyzed by a palladium complex. 相似文献
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镍催化偶联反应机理研究进展(英文) 总被引:1,自引:0,他引:1
近期发展了很多镍催化的偶联反应作为在有机合成中高效构建C–C键的方法,同时开展了很多关于控制镍催化反应活性和选择性的机理研究.这些研究发现,镍催化反应机理往往和相应的钯催化反应机理不同,因为镍催化偶联经常包括自由基和双金属机理.本文总结了镍催化偶联反应机理的最新进展.对于这些反应机理的理解为发展具有更高效率和选择性的镍催化偶联反应提供了帮助. 相似文献