γ-Fe2O3固载Pd-靛红席夫碱配合物作为磁性可回收催化剂用于Heck和Suzuki交叉偶联反应（英文）

A Pd‐isatin Schiff base complex immobilized onγ‐Fe2O3 (Pd‐isatin Schiff base‐γ‐Fe2O3) was synthe‐sized and characterized by Fourier transform infrared, scanning electron microscopy, high resolu‐tion transmission electron microscopy, X‐ray diffraction, thermogravimetric gravimetric analysis, inductively‐coupled plasma, X‐ray photoelectron spectroscopy, and elemental analysis. It was used as a magnetically reusable Pd catalyst for the Heck and Suzuki cross‐coupling reactions.     

果胶负载钯催化剂的制备及Suzuki反应催化性能

以柑橘皮果胶为载体,采用吸附法制备了果胶负载钯催化剂,并将其应用于四苯硼钠与溴代芳烃的交叉偶联反应中.该反应体系以聚乙二醇400(PEG 400)/H2O为反应溶剂,三乙胺为碱,在空气中于110℃反应15~60 min,四苯硼钠中4个苯基均可顺利参与反应,高产率地获得相应的目标化合物.该方法具有条件温和、反应时间短、收率高且催化剂可循环利用等优点.     

MOCVD法制备Pd@ZIF-8催化剂及其催化Suzuki反应性能(英文)

以金属有机骨架化合物ZIF-8为载体,Pd(C3H5)(C5H5)为金属有机前体,采用金属有机气相沉积方法在室温下制备了Pd@ZIF-8催化剂.Pd纳米粒子在ZIF-8载体上均匀分布,粒子尺寸约为1.5–3.5 nm.Pd@ZIF-8在温和条件下对多种卤代芳烃和苯硼酸的偶联反应均具有良好的活性.ZIF-8优异的化学稳定性不仅保证了其在制备过程中结构的完整,而且赋予了催化剂优异的循环使用性能.反应后Pd@ZIF-8材料的晶体结构、孔结构以及粒子分布均未发生明显的变化.     

三(羟甲基)氨基甲烷改性SiO_2固载钯纳米粒子:合成、表征及其催化Heck偶联反应活性（英文）

The preparation of supported Pd nanoparticles on Tris(tris(hydroxymethyl)aminomethane)‐ modi‐fied Si O2 gel and their catalytic application in Heck coupling are investigated. The catalyst was char‐acterized using a combination of X‐ray diffraction, transmission electron microscopy, field‐emission scanning electron microscopy, and scanning electron microscopy/energy‐dispersive X‐ray spec‐troscopy. The supported Pd nanoparticles were found to be a highly active and reusable catalyst for the Heck reaction at a low Pd loading(0.02 mol%) because of stabilization by the Tris moieties. Several reaction parameters, including the type and amount of solvent, base, and temperature, were evaluated. The heterogeneity of the catalytic system was investigated using different approaches, and showed that slight Pd leaching into the reaction solution occurred under the reaction condi‐tions. Despite this metal leaching, the catalyst can be reused seven times without significant loss of its activity.     

活性炭负载硫化锡纳米颗粒作为高效可重复使用Lewis酸催化剂催化三组分一锅法合成4H-吡喃[2,3-c]吡唑衍生物(英文)

Tin sulfide nanoparticles(SnS -NPs) were prepared in aqueous solution at room temperature on the surface of activated carbon(AC) and were investigated using field-emission scanning electron mi-croscopy(FE-SEM), transmission electron microscopy(TEM), X-ray diffraction, reflective ultravio-let-visible spectrophotometry, and spectrofluorimetry. Calculations based on the SEM and TEM images showed that the sizes of the SnS -NPs immobilized on the AC were 30–70 nm. The prepared nanocomposite was used as a heterogeneous Lewis acid catalyst for the three-components one-pot synthesis of 4H-pyrano[2,3-c]pyrazole derivatives in ethanol at 80 ℃. The reactions were efficiently performed in the presence of the prepared catalyst in short reaction times, and gave the desired products in high yields. This catalyst can be easily recovered by simple filtration and recycled up to eight consecutive times without significant loss of its efficiency.     

四乙烯五胺功能化纤维素负载纳米钯催化剂的制备及其对Suzuki反应催化性能的研究

利用四乙烯五胺对环氧化纤维素进行功能化改性,并以其为载体在95％乙醇溶液中现场还原氯化钯制备出四乙烯五胺功能化纤维素负载的纳米钯催化剂.利用IR,XRD,SEM,TEM等分析方法对其进行了表征并用于催化Suzuki交叉偶联反应.实验表明,该催化剂在温和条件下能有效催化卤代芳烃与芳基硼酸的Suzuki交叉偶联反应,该催化剂经回收重复利用5次后,仍具有较高的催化活性.     

氧化石墨烯负载席夫碱钯催化剂的合成、表征及对Suzuki反应催化性能的研究

以修饰的Hummers法制备的氧化石墨烯为载体,席夫碱为配体制备了一种新型的负载型钯催化剂,采用红外光谱仪、透射电镜、X射线光电子能谱仪、热重分析仪和X射线衍射仪等手段对负载型催化剂进行了表征,并评价了其对水相Suzuki反应的催化活性.结果表明,该催化剂在较温和的实验条件下即可高效催化水相芳基卤与芳基硼酸的Suzuki反应,催化剂重复使用5次后,活性基本不变.     

有氧条件下聚(氯乙烯)负载Pd(Ⅱ)配合物高效催化Heck和无铜Sonogashira反应(英文)

A novel poly(vinyl chloride)-supported Pd complex was found to be a highly active catalyst for the Heck and Sonogashira reactions of aryl halides under aerobic conditions.The complex is thermally stable,and can be easily recovered and reused.The catalyst was recycled for the Heck and Sonogashira reactions for five runs without appreciable loss of its catalytic activity,and with negligible metal leaching.     

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.     

硅胶功能化的N-丙哌嗪固载钯纳米粒子作为有效的多相催化剂用于氰化反应(英文)

An efficient heterogeneous Pd catalytic system has been developed, based on immobilization of Pd nanoparticles (PNPs) on a silica-bonded N-propylpiperazine (SBNPP) substrate. The SBNPP substrate effectively stabilizes the PNPs and improves their stability against aggregation. The catalytic activity of this catalyst was investigated in the cyanation of aryl halides with K4[Fe(CN)6 ] as the cyanide source. The catalyst could be recycled several times without appreciable loss of catalytic activity.     

Preparation and characterization of HypoGel-supported Pd nanocatalysts for Suzuki reaction under mild conditions

A new heterogeneous catalyst composed of Pd nanoparticles immobilized within a HypoGel resin has been prepared in the absence of any ligands using an extensive cross-linking method. This new-ly develop...     

Palladium incorporated on carbonaceous catalyst for Suzuki coupling reaction in water

A new palladium incorporated carbonaceous catalyst Pd@CCSO₃HNH₂ was synthesized by introducing palladium on glucose derived carbocatalyst. The catalyst was well characterized and was used for the Suzuki coupling of phenyl boronic acid with different aryl halides under aqueous conditions. This green methodology represents a ligand free, cost-effective and operationally convenient method for the synthesis of a variety of biaryl’s under the conditions that are tolerant for a broad range of functional groups with good to excellent yields. Moreover, the catalyst could be easily recycled and reused at least five times without any significant loss of its catalytic activity.     

Amide as an efficient ligand in the palladium-catalyzed Suzuki coupling reaction in water/ethanol under aerobic conditions

Amide,which is derived from proline and is inexpensive and air-stable,has been synthesized and characterized by ¹H NMR,¹³C NMR,and MS.It was found to be an efficient ligand in the palladium-catalyzed Suzuki cross-coupling reaction.In the Pd/amide catalytic system,aryl bromides can be coupled with phenylboronic acid in ethanol/water（1:2;v/v） in excellent yields even with a low Pd loading of 0.01 mol%.Moreover,the scope of the reaction is broad,and a wide variety of functional groups are tolerant.     

An efficient and recyclable water-soluble cyclopalladated complex for aqueous Suzuki reactions under aerial conditions

Several water-soluble cyclopalladated complexes with five- or six-membered rings have been prepared as air-stable solids from Schiff base ligands bearing an N-phenyl sulfonate groups. Cyclopalladated complexes with six-membered rings show high catalytic efficiency for the Suzuki reactions of aryl bromides with phenylboronic acid in aqueous solvents under mild conditions. Palladium complex 1 can be used for five reaction cycles in high conversions for the Suzuki reactions in neat water without additives. The catalytic process for the Suzuki couplings is proved by TEM analysis to proceed on Pd(0) nanoparticles. Surfactant-protected palladium nanoparticles present lower activities and poorer recyclability for the coupling reactions than those generated in situ without additives.     

纯水中有氧条件下Pd/C催化的无配体Suzuki反应简

报道一种在纯水中Pd/C催化的高效Suzuki反应体系,该体系无需除氧,且无外加配体和添加剂,底物普适性广泛,含有亲水或疏水基团的溴代芳烃都能被高效活化. 此外,对部分杂环芳烃与芳基硼酸的偶联反应也有较好的催化效果. 该催化剂可高效循环使用三次,且性能无明显下降.     

Palladium nanoparticles supported on cucurbit[6]uril: an efficient heterogeneous catalyst for the Suzuki reaction under mild conditions

A new NC palladacycle was synthesized and supported on cucurbit[6]uril (CB[6]). The CB[6]‐supported palladium was used as an efficient nanocatalyst for the Suzuki reaction. In these reactions various aryl halides were reacted with arylboronic acids in H₂O–EtOH at both room temperature and 40 °C. The obtained Pd nanocatalyst exhibited excellent reactivity and stability in C ? C bond formation, which confirms that the catalyst is a completely active heterogeneous species. The Pd nanocatalyst was characterized using X‐ray diffraction, scanning electron microscopy and transmission electron microscopy. Copyright © 2014 John Wiley & Sons, Ltd.     

Heterogeneous Suzuki reactions catalyzed by Pd(0)-Y zeolite

The Pd(0)-Y zeolite showed high activity in the Suzuki cross-coupling reactions of aryl bromides without added ligands. The type of base and organic solvent were found to be critical for the efficiency of the reaction. The presence of water was essential within the reaction medium. The coupling reactions occurred on the external surface of the zeolite. The catalyst is reusable.     

Arylation of pyridine N-oxides via a ligand-free Suzuki reaction in water

We report a practical and highly efficient protocol for the arylation of pyridine N-oxides with arylboronic acid through palladium-catalyzed Suzuki reaction in water.This ligand-free Suzuki reaction is performed in the presence of diisopropylamine and gives 2-or 3-arylated pyridyl N-oxide derivatives in good to excellent yields within 1 h.     

Simple and efficient protocol for catalyst recycling and product recovery in the Pd-catalyzed homogeneous Suzuki reaction

Poly(ethylene oxide) (PEO)/methanol can be used as solvent medium for the Pd-catalyzed Suzuki cross-coupling reaction under mild conditions. After the end of the reaction the product is extracted with heptane and the polar phase can be reused several times without any change in the activity. Pure biaryl products are obtained from the nonpolar phase in excellent isolated yields (>90%). The same catalyst-containing polar phase was used to coupling different aryl halides furnishing the biaryl products in good to high isolated yields.     

Ionic liquid-containing polyethylene supported palladium: a green,highly efficient and stable catalyst for Suzuki reaction

The Suzuki coupling was carried out using a new, efficient and reusable polymer-supported Pd/IL catalyst (PEt@IL/Pd) under aqueous conditions. This catalyst was prepared through coacervation approach followed by treatment with Pd(OAc)₂. The FT-IR, SEM, TGA, TEM, XPS, ICP and EDX techniques were employed to characterize the PEt@IL/Pd. This catalyst exhibited high activity in the Suzuki coupling reaction under green conditions. Moreover, the catalyst could be recycled and reapplied for six times with no appreciable loss in its activity. The leaching test also showed high stability of catalytic Pd species under applied conditions.