共查询到19条相似文献,搜索用时 93 毫秒
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含硫化合物在天然产物、药物、农药和材料中广泛存在,具有多种生物活性或独特功能.C—S偶联反应是合成含硫化合物的重要方法,是有机合成领域的研究热点之一.随着对催化剂的深入开发和对含硫偶联反应物的不断扩展,近年来涌现出大量的C—S偶联反应方法,为含硫化合物的合成提供了便利.芳香卤代烃是合成含硫化合物的主要底物,通过设计不同的反应体系和含硫偶联反应物进行C—S偶联反应,能够高效地合成硫酚、硫醚、二硫醚和砜等含硫化合物.按照不同种类的含硫偶联反应物类型和催化剂种类(钯、铜和镍等)进行分类,综述了近年来以芳香卤代烃为底物的C—S偶联反应,并对代表性反应的机理做了简要说明和比较.此外,还对这一领域目前存在的问题和局限性进行简要分析,并对未来发展方向提出展望. 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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《有机化学》2021,(9)
钯催化的Suzuki-Miyaura偶联反应是目前应用最广泛的合成方法之一.它以卤化物和有机硼化物作为原料,可以高效地构建碳碳键.有机硼化物不仅具有转金属活性,而且与其它主族金属有机试剂相比具有化学性质稳定、安全低毒及合成方法多样的特点. Suzuki-Miyaura偶联反应具有反应条件温和、转化高效和底物普适性广等突出优势,是合成化学研究者构建C—C键的优先选择,而且它已在工业合成领域中被广泛应用.Suzuki-Miyaura偶联反应的快速发展与广泛应用离不开机理研究的进步.近三十年里,诸多研究者设计并开展了细致的机理研究,揭示了Suzuki-Miyaura偶联反应中更多的反应规律. Suzuki-Miyaura偶联反应的催化循环由氧化加成、转金属与还原消除三个过程组成,依次综述了各过程相关机理的研究进展,并在最后简单介绍了无过渡金属参与和无碱参与的Suzuki-Miyaura偶联反应. 相似文献
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C—C键的形成是药物合成过程中重要的研究内容之一.交叉脱氢偶联直接利用不同反应底物中的C—H键在氧化条件下进行交叉偶联反应形成C—C键,反应过程中避免了反应底物的预先官能化,是构建新的碳-碳键简洁、高效的合成路径,原子利用率高、环境友好,具有重大的理论意义和应用价值.综述了目前过渡金属催化的不对称交叉脱氢偶联反应,重点阐述过渡金属与配体在反应的立体选择性中的应用. 相似文献
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First report of a nano‐Cu2O‐catalyzed protocol for homo‐coupling reaction of terminal alkynes in water/ionic liquid medium 下载免费PDF全文
Bo‐Xiao Tang Xiao‐Niu Fang Ren‐Yun Kuang Jian‐Hong Wu Qiao Chen Shao‐Jun Hu Yi‐Lin Liu 《应用有机金属化学》2016,30(11):943-945
A new, efficient and green protocol for the nano‐Cu2O‐catalyzed homo‐coupling reaction of terminal alkynes has been developed, using water/ionic liquid as an environmentally friendly solvent. Moreover, the system also allows the synthesis of unsymmetric 1,3‐diynes by cross‐coupling of two different terminal alkynes. It is noteworthy that the nano‐Cu2O‐catalyzed methodology is a good supplement to copper catalyst for the Glaser‐type homo‐coupling reaction. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Setzer WN Gu X Wells EB Setzer MC Moriarity DM 《Chemical & pharmaceutical bulletin》2000,48(11):1776-1777
The synthesis of a series of diacetylenic compounds related to the natural product falcarindiol has been carried out. Unsymmetrical diacetylenes were prepared by a modification of the Cadiot-Chodkiewicz coupling reaction, while a Glaser coupling was used to prepare symmetrical diacetylenes. These compounds have been tested for in vitro cytotoxic activity against Hep-G2, and H-4-II-E cell lines. Diacetylenes with additional unsaturation at C-1, 2, appended with hydroxyl groups at C-3 and C-8, or with long hydrophobic chains, exhibited IC50 values in the micromolar range. 相似文献
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Emily M. BoydJonathan Sperry 《Tetrahedron letters》2012,53(28):3623-3626
A short synthesis of hemi-dendridine A acetate has been accomplished. The synthesis is based on a modified Fischer indolization that represents a rare example of the single-step synthesis of a 7-oxytryptamine from an ortho-oxygenated phenylhydrazine. The synthetic route required developing an efficient synthesis of N-acetyl-2-pyrroline, the key coupling partner for the modified Fischer indolization. Some interesting chemistry associated with the abnormal Fischer indolization has been uncovered, whereby two molecules of the phenylhydrazine substrate combined along the abnormal reaction pathway, affording an unusual N-phenylindoleamine product. 相似文献
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A visible-light promoted cascade of Glaser coupling/annulation has been developed for one-pot synthesis of polysubstituted pyrazoles from alkynes and hydrazines. The method features mild reaction conditions, readily availible starting materials and green oxidant (O2). It works for a wide range of substituted phenyl acetylene and hyrazines with good functional group tolerance and efficiency. Mechanistic pathways including photochemical irridiation, intramolecular hydrogen-atom-abstraction (HAT) and enamine-to-imine tautomerization was proposed for the transformation. 相似文献
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A Glaser coupling reaction of terminal alkynes in the presence of cupric chloride without organic solvents and bases under near-critical water has been developed. 相似文献
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Prof. Dr. Mohamed Mokhtar Dr. Ghalia Alzhrani Prof. Dr. Elham S. Aazam Prof. Dr. Tamer S. Saleh Dr. Sulaiman Al-Faifi Dr. Subir Panja Prof. Dr. Debabrata Maiti 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(34):8875-8885
Herein, we report the synthesis of nickel-layered double hydroxide amalgamated Y-zeolite (NiLDH@YZ) hybrids and the evaluation of the synergistic effect of various NiLDH@YZ catalysts and mechanochemical agitation on Glaser homocoupling reactions. Nitrogen adsorption-desorption experiments were carried out to estimate the surface area and porosity of NiLDH@YZ hybrids. The basicity and acidity of these hybrids were determined by CO2-TPD and NH3-TPD experiments respectively and this portrayed good acid-base bifunctional feature of the catalysts. The NiLDH@YZ-catalyzed mechanochemical Glaser coupling reaction achieved best yield of 83 % for the 0.5NiLDH@0.5YZ hybrid after 60 min of agitation, which revealed the highest acid-base bifunctional feature compared to all the investigated catalysts. The developed catalyst has proven itself as a robust and effective candidate that can successfully be employed up to four catalytic cycles without significant loss in catalytic activity, under optimized reaction conditions. This work demonstrated a new strategy for C−C bond formation enabled by the synergy between mechanochemistry and heterogeneous catalysis. 相似文献
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PinHuaLI LeiWANG MinWANG JinCanYAN 《中国化学快报》2004,15(11):1295-1298
A Glaser coupling reaction of terminal alkynes in the presence of nickel chloride withoutany organics and bases in hot water has been developed, which produces the correspondinghomo-coupling products in good yields. 相似文献
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Shape-persistent arylene ethynylene macrocycles have attracted much attention in supramolecular chemistry and materials science because of their unique structures and novel properties. In this Review we describe recent examples of macrocycle synthesis by cross-coupling (Sonogashira: aryl acetylene macrocycle or Glaser: aryl diacetylene macrocycle) and dynamic covalent chemistry. The primary disadvantage of the coupling methods is the kinetically determined product distribution, since a significant portion of oligomers grow beyond the length of the cyclic targets ("overshooting"). Better results have been obtained recently by a dynamic covalent approach involving reversible metathesis reactions that afford macrocycles in one step. Mechanistic studies demonstrate that macrocycle formation is thermodynamically controlled by this route. Remaining synthetic challenges include the efficient preparation of site-specifically functionalized structures and larger, more complex two- and three-dimensional molecules. 相似文献
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Jiang Wang Megan E. Hoerrner Mary P. Watson Daniel J. Weix 《Angewandte Chemie (International ed. in English)》2020,59(32):13484-13489
While ketones are among the most versatile functional groups, their synthesis remains reliant upon reactive and low‐abundance starting materials. In contrast, amide formation is the most‐used bond‐construction method in medicinal chemistry because the chemistry is reliable and draws upon large and diverse substrate pools. A new method for the synthesis of ketones is presented here that draws from the same substrates used for amide bond synthesis: amines and carboxylic acids. A nickel terpyridine catalyst couples N‐alkyl pyridinium salts with in situ formed carboxylic acid fluorides or 2‐pyridyl esters under reducing conditions (Mn metal). The reaction has a broad scope, as demonstrated by the synthesis of 35 different ketones bearing a wide variety of functional groups with an average yield of 60±16 %. This approach is capable of coupling diverse substrates, including pharmaceutical intermediates, to rapidly form complex ketones. 相似文献