钯催化卤代芳烃的胺化反应的研究进展

钯催化卤代芳烃的胺化是合成芳胺化合物的重要方法,综述了近年来钯催化卤代芳烃与胺等不同含氮化合物的胺化反应研究进展,重点讨论了钯催化剂配体的结构、反应物比例、溶剂及温度等因素对反应的影响.     

钯催化卤代芳烃的胺化反应研究

钯催化卤代芳烃胺化是形成Car-N的重要方法.配体的发展扩展了底物的适用范围, 提高了反应的选择性,实现了廉价易得的氯代芳烃的胺化,弱碱的使用提高了官能团的兼 容性,因此Pd催化芳胺化广泛应用于合成芳胺类化合物.本文以卤代芳烃为线索,对钯催化偶联胺化反应的研究进展进行了综述和展望.     

胺烷基二茂铁环钯化反应研究

通过一系列实验探讨了胶组分的电子效应与空间结构、反应的投料比、体系的温域等因素对反应的影响．发现了违反Cope准则的现象，阐明了胶组分的电子效应和空间结构、体系的酸碱度和体系的温域是决定生成坏钯化产物的重要因素．     

新型联吡啶配体P-Phos在钯催化胺偶联反应中的应用

P-Phos [2,2′6,6′-四甲氧基吡啶-4,4′-二(二苯基膦)-3,3′-联吡啶]是一类对空气稳定的杂环磷配体。本文以较简单的方法合成了rac-P-Phos配体,并用IR、1H NMR、13C NMR和元素分析等方法进行了表征。首次将P-Phos配体用于催化卤代芳烃和胺的偶联反应中。通过对碱、溶剂和催化剂用量等的筛选,确立了最优化的反应条件。配体对溴代芳烃的催化效果很好,对具有吸电子存在的氯代芳烃,特别是氯代吡啶同样得到了令人满意的结果,分离产率高达97％。催化剂对水和空气的稳定性很好,对胺偶联反应的催化效果很理想,因此是一种有应用前景的催化剂。     

胺作为配体在钯催化偶联反应中应用

对近期我们研究小组及其它研究小组在利用胺作为钯催化偶联反应的配体研究进展进行了总结. 钯/胺作为催化体系主要应用的偶联反应包括: Suzuki-Miyaura交叉反应, Sonogashira交叉反应, Stille交叉反应, Hiyama交叉反应和Heck反应. 研究结果表明胺可以作为价廉和高效的配体促进钯催化交叉偶联反应.     

含氮配体的分子内邻位钯化反应

总结了近年来含氮配体的分子内邻位钯化反应,分析了钯化试剂、金属环大小、溶剂以及底物结构等因素对钯反应的影响以及它们在有机合成中的应用,讨论了邻位钯反应的机制。     

负载离子液体纳米钯催化芳卤羰化反应

研究了高分散性的负载离子液体纳米钯催化剂的制备及其催化芳卤羰化反应的性能. 用XRD、HRTEM和XPS等方法对催化剂进行了表征, 结果表明, 钯组分处于高分散零价态, 其平均粒径小于5 nm, 且催化剂表面存在一厚度适中的离子液体液膜, 有利于提高催化剂的稳定性; 该催化剂对PhI、PhBr、PhCl的羰化反应的催化活性优于离子液体两相催化体系, 在优化的反应条件下, 碘苯的转化率可达99.3％, 生成苯甲酸乙酯的转化频率(TOF)可高达4926 h−1, 反应产物中苯甲酸乙酯的选择性大于99％.     

果胶对钯的吸附及其在有机合成中的应用

以果胶为吸附剂,研究其对钯(Ⅱ)的吸附性能,探讨了溶液的pH值、吸附温度、果胶用量、吸附时间及钯(Ⅱ)溶液的初始浓度对吸附量的影响。 采用Pseudo-First-order、Pseudo-Second-order、Intraparticle、Diffusion、Langmuir、Freundlich和Temkin等模型对实验数据进行线性拟合。 结果表明,果胶对钯(Ⅱ)有很强的吸附性能,吸附率高达96%以上,溶液的最佳pH值为6.5,最佳温度为50 ℃,果胶对钯的吸附量随果胶用量的增加而降低,随钯溶液初始浓度的增加而增加。 吸附动力学遵从Pseudo-Second-order模型,即以化学吸附为主;等温吸附过程符合Freundlich方程;吉布斯自由能为负值,焓变和熵变分别为3.23 kJ/mol和13.32 J/(mol·K),即该过程是自发吸热的;果胶吸附的钯作为催化剂应用到Suzuki反应中,结果表明该催化剂有较高的催化活性。     

钯络合物在有机合成中的一些应用

钯络合物能催化许多反应,在有机合成中有着广泛的应用。钯催化下的反应,产率高,选择性好,反应条件温和。本文介绍了近年来该类反应在有机合成中的一些应用。     

钯催化胺的羰基化反应

综述了钯催化胺的单，双羰基化反应以及钯催化胺基化反应工业及有机合成中的应用，同时对羰基化反应新进展－超临界二氧化碳流体作为反应介质也作了综述。     

Porous Organic Polymer Nanoparticles for Sensing of Unsaturated Hydrocarbons

The design and synthesis of porous organic polymers for the potential application in chemical sensors remains a huge challenge nowadays. Herein, a porous organic polymer possessing tetrazole groups(TTZ-3) was synthesized via simple Schiff base chemical reaction. Thermogravimetric analysis(TGA), Fourier transform infrared spectrometer(FTIR), solid-state¹³C cross polarization/magic angle spinning nuclear magnetic resonance(CP/MAS NMR), transmission electron microscopies(TEM) and field-scanning electron microscopies(FE-SEM) were adopted to cha-racterize the structure and morphology in detail. Significantly, the formed polymers exhibited special detection of unsaturated hydrocarbons through fluorescence enhancement based on photoactivatable 1,3-dipolar cycloaddition reactions. Furthermore, the reaction activity of different unsaturated hydrocarbons towards the polymers was investigated. This work highlights the great potential of porous organic polymers as chemical sensors in realizing environmental pollution monitoring and reducing the incidence of disease, such as chronic obstructive pulmonary disease.     

Electron-Driven Nitration of Unsaturated Hydrocarbons

Herein, we introduce an electrochemically assisted generation of nitryl radicals from ferric nitrate under mild reaction conditions using a simple setup with inexpensive graphite and stainless-steel electrodes. The mechanism of the reaction is supported by detailed spectroscopic and experimental studies. Powered by electricity and driven by electrons, the synthetic diversity of this reaction has been demonstrated through the development of highly efficient nitration protocols of various unsaturated hydrocarbons. In addition to a broad application area, these protocols are easy to scale for decagram quantities, and exhibit exceptional substrate generality and functional-group compatibility.     

Synthesis of Esters from Cage-Like Unsaturated Hydrocarbons,Carboxylic Acid Anhydrides,and Water

A convenient method for the preparation of esters was developed on the basis of reaction of cage-like polycyclic olefins with carboxylic acid anhydrides and water. Mixed anhydrides were found to give rise to the corresponding low-molecular acid esters. Among the obtained esters, acetates possess a pleasant odor, and they can be used as components of synthetic fragrant substances.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 7, 2005, pp. 995–998.Original Russian Text Copyright © 2005 by Mamedov, Nabieva, Rasulova.     

二氧化碳与不饱和烃的还原羧化反应

过渡金属催化CO₂参与的不饱和烃还原羧化反应是合成羧酸及丙烯酸类化合物的重要途径, 具有重要的研究价值和工业应用潜力．过渡金属试剂与不饱和烃、CO₂生成稳定的金属杂环内酯或金属羧酸盐．还原剂能够与金属杂环内酯或金属羧酸盐发生转金属作用, 重新生成活泼催化剂, 从而实现催化剂的循环利用．本文总结了还原剂, 包括有机金属试剂、硅烷、硼烷、金属粉末、甲醇和氢气等在不饱和烃与CO₂的还原羧化反应中的应用, 并着重描述其反应特点和反应机理.     

Synthesis of polysubstituted furans by palladium-catalyzed coupling of butatrienyl carbinols with aryl halides and triflates

An efficient one-pot two-step synthesis of polysubstituted furans is described using readily available 4,5-epoxy-2-alkynyl esters as starting materials. In the first step, reduction of these with SmI₂ affords buta-1,2,3-trienyl carbinol intermediates which, in the second step, participate in Pd(0)-catalyzed cyclization reactions with aryl halides and triflates by a mechanism probably involving oxidative addition, intramolecular oxypalladation and reductive elimination steps. In this manner, up to four carbon substituents are incorporated onto the furan ring, with the aryl group being introduced at the furan 3- or 4-positions. These features make the method particularly suitable for regioselective synthesis of tetrasubstituted furans.     

不饱和链烃沸点的拓扑研究

基于邻接矩阵与边价 (fi)定义边价连接性指数 ( mF) ,其中的0 F ,1 F与 2 94种不饱和链烃 (包括烯烃、炔烃及烯炔烃 )的沸点 (Tb)关联 ,得到良好的数学模型 :ln( 70 0 -Tb) =6 5 2 3 3 1-0 0 0 4880 F2 -0 3 46771 F0 5(n =2 94,R =0 9979,R2 =0 995 8,F =3 490 4,S =5 12 ) ,该回归模型经Jackknife法检验具有总体稳健性 .可以预示 ,该指数将在定量构效关系研究中成为重要参数 .     

The Dendralenes—a Neglected Group of Highly Unsaturated Hydrocarbons

Dendralenes are acyclic and cyclic cross-conjugated polyolefins derived from 3-methylene-1,4-pentadiene. This review summarizes and compares, for the first time, the methods developed for the synthesis of this class of hydrocarbons. Because of their particular arrangement of π-electrons, the dendralenes are novel substrates for addition and rearrangement reactions, and model compounds for spectroscopic studies.     

一氧化碳参与不饱和烃类化合物羰基化反应的研究进展

不饱和烃类化合物的羰基化反应是指在过渡金属催化剂存在条件下, 将一氧化碳(CO)分子以羰基的形式插入到烯烃(或者炔烃)与不同的亲核试剂中, 合成更高附加值化学品的转化过程. 本文综合评述了羰基化反应合成高附加值化学品的重要性, 介绍了几种不同类型的羰基化反应(氢甲酰化反应、 氢酯化反应、 氢酰胺化反应和氢羧基化反应)在发展新型催化剂体系及高效合成目标产物方面的研究进展, 并对羰基化反应存在的问题及未来发展方向和趋势进行了展望.     

Metal‐Free Hydrogenation of Unsaturated Hydrocarbons Employing Molecular Hydrogen

The metal‐free activation of hydrogen by frustrated Lewis pairs (FLPs) is a valuable method for the hydrogenation of polarized unsaturated molecules ranging from imines, enamines, and silyl enol ethers to heterocycles. However, one of the most important applications of hydrogenation technology is the conversion of unsaturated hydrocarbons into alkanes or alkenes. Despite the fast development of the FLP chemistry, such reactions proved as highly challenging. This Minireview provides an overview of the basic concepts of FLP chemistry, the challenge in the hydrogenation of unsaturated hydrocarbons, and first solutions to this central transformation.