乙二胺功能化纤维素负载纳米钯催化Suzuki反应的研究

以氯化纤维素为原料, 通过与乙二胺的胺化反应制得乙二胺功能化纤维素(Cell-EDA), 然后再将胺化纤维素在氯化钯乙醇溶液中反应可以方便制备得到乙二胺功能化纤维素负载的纳米钯催化剂(Cell-EDA-Pd0). 用SEM, TEM等分析方法对所制备的催化剂进行了表征; TEM分析表明乙二胺功能化纤维素负载的纳米钯呈球形, 粒径在10～20 nm左右. 实验结果表明, Cell-EDA-Pd0催化剂对空气稳定, 无需在惰性气体的保护下就能有效地催化芳基硼酸与卤代芳烃的Suzuki交叉偶联反应, 催化剂易回和收重复使用, 催化剂重复使用6次催化活性没有明显降低.     

钯/碳高效绿色催化Suzuki交叉偶联反应

开发了一个以钯/碳为催化剂高效绿色催化Suzuki反应制备联苯类化合物的新方法.该体系以环境友好的聚乙二醇400的水溶液为反应溶剂,加入离子液体1-甲基-3-丁基咪唑双三氟甲磺酰亚胺盐,可高效催化溴代芳烃与芳基硼酸的Suzuki交叉偶联反应,并且催化剂可以循环利用4次而催化效率没有明显降低.     

一种含吡啶配体氮杂环卡宾钯络合物(NHC)PdCl_2(Py)的合成及其高效催化偶联反应

通过两步反应合成了一种卡宾配合物(NHC)Pd Cl2(Py),该配合物在有氧条件下能够高效地催化Suzuki偶联反应、Heck偶联反应和Sonogashira偶联反应.对于Suzuki偶联和Sonogashira偶联,仅使用0.1 mol%催化量的催化剂就能取得较好的收率.而对于不活泼的Heck偶联,使用1 mol%催化量的催化剂也能得到较好的产率.     

Suzuki反应中催化体系的研究进展

随着过渡金属催化的交叉偶联反应的出现,有机合成化学在20世纪的最后25年得到了快速的发展,并且这些反应的重要性被普遍认可.其中,Suzuki偶联反应因其多功能性、兼容性和对包括材料科学和药物合成在内的多种学科的关键贡献,而占据了更加特殊的地位.尽管到2010年为止Suzuki反应已取得重大进展,但随着可持续和绿色化学发展的需求,Suzuki反应的催化体系仍待进一步优化提高.这里概述的催化剂为C-C键的构建提供了方便和绿色的合成途径.在这篇综述中,我们总结了科研工作者对于Suzuki反应在改进催化剂制备策略、优化催化反应条件、提高催化剂重复利用性能和降低催化剂成本方面做的一系列研究.     

Ni催化的Suzuki偶联反应

本文主要对Ni催化的Suzuki偶联反应的发展历程和近年来碳卤键断裂类、碳氧键断裂类、碳碳键断裂类、碳氮键断裂类和碳硫键断裂类Ni催化Suzuki偶联反应进行总结。通过近十年研究,各类新型催化剂、配体、添加剂不断被开发,使反应活性大为提高,反应条件越来越温和。对目前认为Ni催化的Suzuki偶联反应的机理进行了梳理,发现Ni催化的Suzuki偶联反应催化剂循环方式有两种,即Ni(0)/Ni(Ⅱ)循环和Ni(Ⅰ)/Ni(Ⅲ)循环。因此,本文认为研究和发展价廉的金属Ni催化剂是研究Suzuki偶联反应的一个重要方向,未来Ni催化Suzuki偶联反应的研究将会集中在机理探究、新型催化剂和配体设计、多类型碳碳键构建(Csp~2-Csp~3、Csp~3-Csp~3)以及广泛底物的不对称Ni催化的Suzuki偶联反应。     

无过渡金属催化的Suzuki-Type交叉偶联反应研究进展

过渡金属催化的Suzuki交叉偶联反应是构建碳碳键最高效和最广泛的方法之一,其广泛的研究极大地推动了合成化学的发展.当前Suzuki交叉偶联反应主要依赖于贵金属钯催化体系,然而,金属钯储量低、价格昂贵及高毒性等弊端已经严重地限制了其在现代合成中的发展.在过去二十年时间,无金属催化的Suzuki-Type交叉偶联反应受到了广泛的关注,许多新型高效的反应体系被开发报道.总结了近二十年无金属催化的Suzuki-Type交叉偶联反应的研究进展,主要涉及的反应类型包括碱、金属有机试剂和有机小分子促进的反应,并对相关的反应机理进行了阐述.     

纳米钯催化芳基重氮盐的Suzuki和Heck偶联反应

开发了一种使用纳米Al2O3作载体,由四三苯基膦钯衍生的纳米钯催化剂催化的使用芳基重氮盐作原料的高效绿色Suzuki和Heck偶联反应来制备联苯类和芳基烯类化合物的方法.该反应体系以乙醇作反应溶剂,在空气中于25℃下,催化剂可高效催化芳基重氮盐分别与芳基硼酸和烯烃的Suzuki和Heck偶联反应,各类考察的反应底物都给出较高的收率,而且催化剂循环利用4次后,其催化活性和反应收率都没有明显降低.     

光催化Suzuki偶联反应的非均相催化剂研究进展

Suzuki偶联反应作为构建C-C键的最有效的手段之一,在医药、染料和电子工业等领域扮演着重要的角色。传统的Suzuki偶联反应催化体系需要依赖化石能源产生的热能来驱动,不仅造成了不可再生资源的消耗,还会导致相应的环境问题。近年来,光催化技术和绿色有机合成化学蓬勃发展,利用可再生的太阳能光催化Suzuki偶联反应不但可以解决在催化反应过程中的能源与环境问题,还可以在温和条件下获得高产率的联苯化合物产物,正在受到人们的广泛关注。与均相光催化剂相比,非均相光催化剂具有良好的化学稳定性、便捷的可回收性与优异的循环利用性能等优点,因此成为光催化Suzuki偶联反应的研究重点。本文总结了非均相催化剂光催化Suzuki偶联反应的基本原理,介绍了近年来科研工作者对光催化Suzuki偶联反应中非均相催化剂的制备方法、催化性能以及可循环利用性等方面做的一系列研究。     

纳米钯催化的高效Suzuki偶联反应

开发了一种使用Al2O3作载体,由四三苯基膦钯制备的纳米钯催化剂催化的高效绿色Suzuki反应来合成联苯类化合物的方法.该反应体系以DMF和H2O的混合体系作反应溶剂,在空气中于25~90℃下,催化剂可高效催化卤代芳烃与芳基硼酸的Suzuki偶联反应,所有考察的反应底物都给出很高的收率,并且催化剂循环利用6次后,其催化活性和反应收率都没有明显降低.     

P⌒O环钯配合物的合成及对Suzuki交叉偶联反应的催化性能

P⌒O环钯配合物的合成及对Suzuki交叉偶联反应的催化性能;合成;二苯基膦丙酸钠;Suzuki偶联反应     

Facile approach to the electrochemical synthesis of palladium-reduced graphene oxide and its application for Suzuki coupling reaction

Electrochemically codeposited palladium nanoparticles (Pd NPs) and reduced graphene oxide (ERGO-Pd) were used as catalyst for Suzuki cross coupling reactions. The catalyst was characterized by various analytical techniques. The mean particle size of Pd was found to be 5.7 ± 1.8 nm. The ERGO-Pd catalyst demonstrated excellent catalytic activity and recyclability for Suzuki cross coupling reactions. The remarkable reactivity of the ERGO-Pd catalyst toward cross-coupling reactions is attributed to the high degree of the dispersion of Pd NPs on reduced graphene oxide with narrow size distribution from 3 to 9 nm.     

Chitosan-supported palladium(0) catalyst for microwave-prompted Suzuki cross-coupling reaction in water

A chitosan-supported palladium (Pd) (0) catalyst was prepared by simple adsorption of palladium(II) ion onto chitosan beads and a subsequent reduction process. To maintain mechanical stability, the chitosan-supported palladium(0) catalyst was cross-linked with either glutaraldehyde or diglycidyl ether polyethylene glycol. The catalysts were utilized for the Suzuki cross-coupling reaction in water. The catalyst, in the presence of a tetrabutylammonium bromide (TBAB) additive, showed excellent catalytic activity in microwave-prompted Suzuki cross-coupling reactions using various aryl halides and boronic acids. In addition, the catalyst was successfully reused up to five times without significant loss of catalytic activity.     

Pd(0)-Schiff-base@MCM-41 as high-efficient and reusable catalyst for C–C coupling reactions

A Pd-Schiff-base grafted on functionalized mesoporous MCM-41 (Pd(0)-Schiff-base@MCM-41) was prepared using a post-grafting procedure and used as a highly efficient and reusable nanostructural catalyst for the carbon–carbon cross-coupling reactions of various aryl halides (including aryl iodide, bromide and chloride) with sodium tetraphenyl borate, phenylboronic acid and butyl acrylate. This catalyst exhibits interesting reactivity through Heck and Suzuki reactions.     

Nanoporous phenanthroline polymer locked Pd as highly efficient catalyst for Suzuki-Miyaura Coupling reaction at room temperature

Because of the intrinsic advantages, Suzuki coupling reactions have been one of the most popular coupling reactions in organic synthesis, however developing a high-performance heterogeneous catalyst for Suzuki coupling reactions in aqueous media at low temperature (e.g. room temperature) is still a challenge. Herein, a heterogeneous catalyst with coordinated Pd as active site and a designed conjugated phenanthroline based porous polymer (CPP) as support was fabricated. Systematically investigation on CPP support by Fourier transform infrared spectroscopy (FT-IR), Thermogravimetric analysis (TGA), Transmission electron microscopy (TEM), N₂ adsorption–desorption isotherm and Scanning electron microscopy (SEM) show that the derived CPP catalyst support owns a porous structure, moderately good surface area (141 m²/g) and an excellent thermal stability. As a heterogeneous catalyst for the synthesis of biphenyl derivatives via Suzuki coupling, Pd/CPP achieves an excellent catalytic performance and recycling ability towards Suzuki reaction of various reactants at room temperature in ethanol-water medium.     

Mizoroki–Heck and Suzuki–Miyaura reactions mediated by poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid)‐stabilized magnetically separable palladium catalyst

The purpose of this work was to synthesize and characterize a new magnetic polymer nanosphere‐supported palladium(II) acetate catalyst for reactions requiring harsh conditions. In this regard, an air‐stable, moisture‐stable and highly efficient heterogenized palladium was synthesized by the coordination of palladium(II) acetate with poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid)‐grafted modified magnetic nanoparticles with a core–shell structure. The structure of the newly developed catalyst was characterized using various techniques. The catalytic activity of the resultant nano‐organometallic catalyst was evaluated in Mizoroki–Heck and Suzuki–Miyaura reactions to afford the corresponding coupling products in good to excellent yields. High selectivity as well as outstanding turnover number (14 143, 4900) and turnover frequency (28 296, 7424) values were recorded for the catalyst in Suzuki–Miyaura and Mizoroki–Heck reactions, respectively. Magnetic separation and recycling of the catalyst for at least six runs became possible without any significant loss of efficiency or any detectable palladium leaching.     

正电性磁性氧化铁胶粒负载钯催化的Suzuki偶联反应

发展了一种超顺磁性Fe3O4纳米粒子负载Pd0的简易方法. 利用Fe3O4溶胶带正电荷的特性, 将负离子 通过静电作用吸附在Fe3O4胶体粒子表面( /Fe3O4), 以抗坏血酸(Vc)进一步还原即得到载有金属Pd团簇的Fe3O4胶体粒子(Pd0/Fe3O4). 该磁性载体负载的Pd催化剂对Suzuki反应表现出良好的催化活性, 且在反应后, 可方便地通过永久磁铁将催化剂从反应体系中分离出来, 进行循环使用. 试验表明, 该催化剂在循环使用五次后反应活性无明显下降. 进一步试验发现, 这种磁性纳米粒子负载的金属钯对一系列卤代芳烃的Suzuki偶联反应均表现出较优的催化活性.     

Reusable Pd nanoparticles immobilized on functional ionic liquid co-polymerized with styrene for Suzuki reactions in water-ethanol solution

Co-polymer of 3-(2,3-dihydroxypropyl)-1-vinylimidazolium chloride and styrene was synthesized and used as a support of Pd nanoparticles. The Pd@poly-Sty-co-diOH-Cl catalyst can efficiently catalyze Suzuki reactions for a wide range of aryl iodides and bromides with 0.05 mol % Pd at 70 °C in water-ethanol solution under air, and the catalyst can be recycled and reused for several times without significant loss of activity.     

Synthesis of diarylmethane derivatives from Stille cross-coupling reactions of benzylic halides

A catalyst precursor prepared in situ from palladium acetate and a phosphine ligand was used for the Stille cross-coupling reaction of benzylic bromides and chlorides with aryltributyltin analogues. The reactions were performed at 80 °C using dppf as ligand in the presence of KF, or more conveniently using PPh₃ in the absence of base, furnishing diarylmethane derivatives in high yields (86-99%). Using Pd(OAc)₂/PPh₃ as catalyst precursor competitive Stille and Suzuki cross-coupling reactions with benzyl chloride showed that in the absence of base or in the presence of KF the Stille product is the majority product, and only the Suzuki product was obtained in the presence of KOH as base.     

Palladium nanoparticles immobilized on magnetic methionine‐functionalized chitosan: A versatile catalyst for Suzuki and copper‐free Sonogashira reactions of aryl halides at room temperature in water as only solvent

The preparation of an efficient heterogeneous catalyst system based on the immobilization of palladium nanoparticles on a magnetic nanoparticle core (ImmPd(0)‐MNPs) is described. The new catalytic system was characterized using transmission and scanning electron microscopies, X‐ray diffraction, energy‐dispersive X‐ray and Fourier transform infrared spectroscopies, thermogravimetric analysis, vibrating sample magnetometry and inductively coupled plasma analysis. We have demonstrated that ImmPd(0)‐MNPs is an efficient and reusable catalyst for the Suzuki–Miyaura and Sonogashira coupling reactions of various types of aryl halides in water as a green and environmentally acceptable solvent. Moreover, the reactions were carried out efficiently at room temperature. The catalyst was easily separated using an external magnet from the reaction mixture and recycled ten times without significant loss of activity.