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1.
魏晓芳 《有机化学》2005,25(2):234-237
对钯催化的Grignard类型反应作了论述.总结了钯催化的有机卤化物或炔烃与C=O键或C≡N键的二组分反应和有机卤化物、烯烃或炔烃与C=O键或C≡N键的三组分反应.在这些反应中的C-Pd键是通过C-X键与Pd(0)的氧化加成或通过碳碳双键或叁键的碳/亲核钯反应生成,C-Pd键与C=O键或C≡N键之间的反应一般为分子内反应.当然,人们也观察到了通过芳香C-H键活化产生的芳基碳钯键与腈基的分子间反应.在这些反应中催化剂的再生是关键.本工作对反应的机理也作了一些探讨.  相似文献   

2.
60年来稀土金属有机配合物化学取得重要发展. 辅助配体从环戊二烯基,五甲基环戊二烯基,茚基发展到各种非茂配体,如双酚,β-二亚胺,胍基,脒基等. 配合物的种类从简单的三茂稀土配合物发展到各种形式的二茂稀土配合物和单茂稀土配合物. 非茂配体的应用不仅拓展了稀土金属有机配合物的结构种类,还极大推动稀土金属有机配合物在高分子和有机合成中的应用. 稀土金属有机配合物可有效催化烯烃均聚与共聚,共轭双烯烃以及极性单体的选择性聚合. 稀土金属有机配合物还能催化氢化,氢胺化和膦氢化等重要有机反应. 本文对稀土金属有机配合物化学过去60年的发展进行综述.  相似文献   

3.
活性钌、锇-配体多重键配合物研究进展   总被引:1,自引:0,他引:1  
金属一配体多重键配合物的反应性研究有助人们深入理解许多重要的金属催化过程,如生物体系中的氧化和固氮及有机合成中的金属催化原子或基团转移反应.含Os=N多重键的锇(VI)氮合物在还原剂存在下发生氮偶合反应生成双核氮分子桥连配合物,为与固氮机理有关的金属氮合物氮偶合反应提供实验证据.一系列具有可调结构和氧化性含M=O,M=NR,M=CR^1R^2(M=Ru,Os)多重键的活性钌/锇氧合物,钌亚胺基配合物,钌/锇卡宾配合物(包括手性配合物)已被成功分离,其结构已通过光谱手段和x射线单晶衍射确定.这些活性金属一配体多重键配合物分别能与有机化合物发生氧原子、亚胺基、卡宾转移反应,包括烯烃环氧化、环氮化、环丙烷化、cis双羟基化,c—H键羟基化、酰胺化、卡宾插入等,从而允许直接研究相应催化过程中金属.配体多重键中间体的原子或基团转移反应,为金属催化原子或基团转移反应(包括不对称催化反应)提供重要机理信息.已发展出一系列涉及钌.配体多重键活性物种的高选择性钌催化反应,包括2,6-Cl2pyNO与烯烃的环氧化和Wacker型氧化成醛,H2O2水溶液氧化烯、炔烃和醇为羧酸或cis-二醇,PhI=NR与饱和c—H键的酰胺化,重氮化合物的卡宾偶合,分子内卡宾插入c—H键,重氮化合物、亚胺、烯/炔烃的三组分偶合,及以“PhI(OAc)2+RNH2”为氮源的金属催化C—N键形成反应等.  相似文献   

4.
二氯二茂锆同异丁基格氏试剂以1:2摩尔比反应,于室温下生成有机锆中间体,后者同烯烃、炔烃或二烯反应。最后生成不原的二聚物或分子内环化产物。  相似文献   

5.
过渡金属催化导向碳氢键活化与不饱和分子的环化反应已成为合成复杂碳环和杂环化合物的高效途径,但反应中往往需要额外加入化学计量化学氧化剂来实现反应循环.电化学有机合成可利用电流代替昂贵、有毒的化学氧化剂,是一种环境友好的绿色合成手段.近年来,电化学有机合成与过渡金属(如Pd、Ni、Co、Ru、Cu、Rh、Ir等)催化碳氢键活化的结合取得了显著的进展.重点介绍了过渡金属催化导向C—H活化与炔烃、烯烃、一氧化碳和异氰等不饱和分子的电氧化环化反应的最新进展,并对该领域未来发展方向进行了展望.  相似文献   

6.
正钯催化Heck偶联反应一般首先经过插入和加成步骤生成含C—Pd键中间体A,最后通过β-H消除来实现钯催化循环.如何利用中间体A中的C—Pd键引入新官能团是有机合成研究难点之一.目前有两种策略:(1)零价钯催化体系下,烯烃与卤代烃反应生成含C—Pd键中间体A,然后与亲核试剂(芳基硼酸,Cl-,CO,烯烃和炔烃等)实现烯烃双官能团化反应;(2)两价钯/氧化剂催化体系下,烯烃与有机金属试剂反应生成含C—Pd键中间体A,然后与亲核试  相似文献   

7.
二氯二茂锆同异丁基格氏试剂以1:2摩尔比反应,于室温下生成有机锆中间体,后者同烯烃、炔烃或二烯反应,最后生成还原的二聚物或分子内环化产物。  相似文献   

8.
钯催化反应是广泛被用于有机合成的简单而又重要的反应。主要综述钯类催化剂在形成碳-碳单键反应中的应用,着重阐述了卤代烃与有机金属化合物、烯烃、炔烃的交联反应。  相似文献   

9.
沈琪 《中国稀土学报》1993,11(4):353-363
综述了中国稀土金属有机化学的进展。包括三环戊二烯基稀土配合物,环戊二烯基稀土氯化物,含有稀土碳σ键配合物,稀土有机氢化物,烯丙基稀土配合物,环辛四烯基稀土衍生物,中性芳烃稀土配合物,二价稀土配合物及含过渡金属,稀土异核配合物的合成和结构以及稀土有机化合物催化烯烃氢化、异构化、聚合和在脱卤、脱氧、脱硫等反应中的应用。  相似文献   

10.
1967年,Fujiwara和Moritani首次报道了一种新型的交叉偶联反应,该反应是在过渡金属通常是钯的作用下芳基碳氢键直接偶联到烯烃碳氢键上,生成新的碳碳键.在接下来的几十年时间里,钯催化的氧化偶联反应成为了一种重要的有机合成手段,在相关领域已经涌现出很多令人瞩目的科研成果.综述了Pd催化下烯烃、炔烃及芳烃的氧化偶联反应研究进展.  相似文献   

11.
Cyclocarbonylation reactions proceed mainly by the coupling reactions of carbonylation components with cyclization components having an unsaturated π-electron bond, in the presence of transition metal compounds. The representative reactions are cyclocarbonylation of alkynes by carbon monoxide such as Pauson–Khand reactions, hetero Pauson–Khand reactions, cyclocarbonylation of alkynyl alcohols, cyclocarbonylation of alkynyl amines, cyclocarbonylative alkyne–alkyne coupling reactions, and reductive cyclocarbonylation of alkynes. The other reactions are cyclocarbonylation of alkenes by carbon monoxide such as alkene–alkene coupling reactions, cyclocarbonylation with aldehydes, ketones, amines or imines, cyclocarbonylation of alkenyl alcohols. Carbonylation via cyclometalation, carbonylative ring expansion reactions, cyclocarbonylation by aldehydes, carboxylic acids or carboxylic acid esters are also cyclocarbonylation reactions. These reactions are conveniently used for organic syntheses, especially, for the syntheses of pharmaceutical intermediates.  相似文献   

12.
Alkynes have two sets of mutually orthogonal π‐bonds that are different from the π‐bonds of alkenes. These π‐bonds are able to bond with transition metal compounds. Alkynes easily bond with the various kinds of compounds having a π‐bond such as carbon monoxide, alkenes, other alkynes and nitriles in the presence of the transition metal compounds. The most representative reaction of alkynes is called the Pauson–Khand reaction. The Pauson–Khand reactions include the cyclization of alkynes with alkenes and carbon monoxide in the presence of cobalt carbonyls. Similar Pauson–Khand reactions also proceed in the presence of other transition metal compounds. These reactions are the first type of characteristic reaction of alkynes. Other various kinds of cyclizations with alkynes also proceed in the presence of the transition metal compounds. These reactions are the second type of characteristic reaction of alkynes. These include cyclooligomerizations and cycloadditions. The cyclooligomerizations include mainly cyclotrimerizations and cyclotetramerizations, and the cycloadditions are [2 + 2], [2 + 2 + 1], [2 + 2 + 2], [3 + 2], [4 + 2], etc., type cycloadditions. Alkynes are fairly reactive because of the high s character of their σ‐bonds. Therefore, simple coupling reactions with alkynes also proceed besides the cyclizations. The coupling reactions are the third type of characteristic reactions of alkynes in the presence of, mainly, the transition metal compounds. These reactions include carbonylations, dioxycarbonylations, Sonogashira reactions, coupling reactions with aldehydes, ketones, alkynes, alkenes and allyl compounds. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

13.
硅杂四元环化合物的合成和反应   总被引:1,自引:0,他引:1  
硅杂四元环化合物在有机硅化学中是一类非常重要的小分子环系化合物, 广泛应用于有机化学、金属有机化学以及材料化学. 环上只含有一个硅原子的硅杂环丁烷可以通过γ-卤代丙基硅烷的Grignard反应、Si=C键与烯烃的 [2+2]环加成反应以及硅杂环丙烷的扩环反应合成, 环上只含有一个硅原子的硅杂环丁烯可以通过格氏试剂或锂试剂参与的Si—C键的关环反应、硅杂环丁烷的转化反应、硅卡宾对C—H键的插入反应、Si=C键与炔烃的[2+2]环加成反应以及二炔基硅烷的分子内成环反应等途径合成. 硅杂环丁烷和硅杂环丁烯由于存在环张力和具有一定的Lewis酸性, 能够通过扩环反应生成五元和六元含硅杂环化合物, 也能够通过开环反应生成不同结构的有机硅分子和聚合物, 抑或实现有机反应在温和条件下的转化.  相似文献   

14.
离子液体/超临界二氧化碳两相体系在有机合成中的应用   总被引:1,自引:0,他引:1  
介绍了近年来在离子液体/超临界二氧化碳两相体系中进行有机合成的最新进展, 包括烯烃氢甲酰化反应、酶催化反应、二氧化碳和环氧化物的环加成反应、烯烃环氧化反应、烯烃不对称二羟化反应、氢化反应、Heck反应、醇氧化反应、烯烃氢乙烯化反应、烯烃二聚反应等.  相似文献   

15.
Anti-Bredt alkenes, bicyclic molecules that contain a bridgehead double bond, were for many years regarded as chemical curiosities. The type 2 intramolecular Diels-Alder (IMDA) reaction provides a one-step entry into this fascinating class of molecules. The reaction has made available numerous anti-Bredt alkenes for structural and chemical studies. X-ray crystallography has revealed the magnitude of the deformations associated with the bridgehead double bond, and rate studies of reactions of bridgehead alkenes have allowed quantification of the kinetic consequences of the torsional distortions. More recently, the type 2 intramolecular Diels-Alder reaction and the resulting anti-Bredt alkenes have found application in organic synthesis. The constraints resulting from the connectivity in the Diels-Alder precursor creates a strong regio- and stereochemical bias in the cycloaddition step. The end result of this bias is the stereoselective synthesis of highly substituted six-membered rings. The reaction also achieves a facile synthesis of seven- and eight-membered rings in a single step from acyclic precursors. The utility of this reaction has been verified in recent applications of the type 2 IMDA reaction as a key step in the total synthesis of complex natural products.  相似文献   

16.
Under microwave irradiation and solvent‐free conditions, rare‐earth metal chlorides (RECl3) have been efficient catalysts for one‐pot synthesis of quinoline derivatives to give products in good to excellent yields through the multi‐component reactions of aldehydes, amines, and alkynes. The rare‐earth metal chlorides can be recycled for six times without notable loss of catalytic activities. This new synthetic approach has prominent features of a short reaction time, high yields of products, operational simplicity, broad substrate scopes, environmentally friendly property and commercially available catalysts. It extends the applications of rare‐earth metal compounds as catalysts in organic synthesis.  相似文献   

17.
许斌  麻生明 《有机化学》2001,21(4):252-262
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   

18.
1,2-Bis(diphenylphosphino)ethenes and -ethanes (DPPEs) are among representative supporting ligands in transition metal catalysts, which can promote otherwise challenging organic transformations with high efficiency and selectivity. Such bidentately coordinating ligands are conventionally prepared by nucleophilic substitution reactions of halogenated carbon electrophiles with nucleophilic metal phosphides. However, they suffer from poor functional group compatibility and/or tedious preparation of highly functionalized starting substrates. In this context, additions of phosphines to readily available and simple alkynes and alkenes have recently received significant attention. This digest paper focuses on recent developments of diphosphination of alkynes and alkenes for the synthesis of DPPE-type ligands. The reported approaches are categorized into several types of reactions, and their scope, limitation, and mechanism are briefly summarized.  相似文献   

19.
The de novo synthesis of small organic heterocyclic molecules has benefited from recent protocols for copper-facilitated additions of heteroatoms to alkenes, alkynes and arenes. This tutorial review summarizes a number of these recent contributions. Copper salts can facilitate bond formations due to their ability to serve as Lewis acids, oxidizing agents and transition metal catalysts. The current understanding of the mechanisms of these reactions is presented. This review should be of interest to chemists involved in the synthesis of heterocycles and those investigating transition metal facilitated reactions.  相似文献   

20.
An expanded substrate scope and in-depth analysis of the reaction mechanism of the copper(II) carboxylate-promoted intramolecular carboamination of unactivated alkenes is described. This method provides access to N-functionalized pyrrolidines and piperidines. Both aromatic and aliphatic gamma- and delta-alkenyl N-arylsulfonamides undergo the oxidative cyclization reaction efficiently. N-Benzoyl-2-allylaniline also underwent the oxidative cyclization. The terminal olefin substrates examined were more reactive than those with internal olefins, and the latter terminated in elimination rather than carbon-carbon bond formation. The efficiency of the reaction was enhanced by the use of more organic soluble copper(II) carboxylate salts, copper(II) neodecanoate in particular. The reaction times were reduced by the use of microwave heating. High levels of diastereoselectivity were observed in the synthesis of 2,5-disubstituted pyrrolidines, wherein the cis substitution pattern predominates. The mechanism of the reaction is discussed in the context of the observed reactivity and in comparison to analogous reactions promoted by other reagents and conditions. Our evidence supports a mechanism wherein the N-C bond is formed via intramolecular syn aminocupration and the C-C bond is formed via intramolecular addition of a primary carbon radical to an aromatic ring.  相似文献   

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