二茂铁烯丙基钯卡宾络合物的合成及其催化性能

采用"一锅法"用1, 3-双(2, 6-二异丙基苯基)氯化咪唑对二茂铁烯丙基钯二聚体Ⅰ在室温下进行解聚,不仅简便、高效地合成了二茂铁烯丙基钯卡宾络合物Ⅱ,而且避免了使用不稳定的卡宾。通过IR、1HNMR、13CNMR、MS、HRMS和X射线单晶衍射对其结构进行鉴定。络合物Ⅱ对空气和湿气稳定,且对芳基氯代物参与的Suzuki-Miyaura偶联反应和Buchwald-Hartwig胺化反应展现较高的催化活性。在反应温度70℃、0.4%(以氯代芳烃物质的量为基准计算得到,下同)络合物Ⅱ催化芳基氯代物与芳基硼酸的偶联反应时,产物收率为92%～100%;在反应温度100℃、0.5%络合物Ⅱ催化氯苯与多样化胺的偶联反应时,获得38%～99%的收率。     

Suzuki偶联反应中钯配合物催化剂的研究进展

Suzuki偶联反应是在零价钯配合物催化剂的催化下,芳基硼酸与卤代芳烃进行的交叉偶联反应,可以高效、高选择性地构建C-C键.钯配合物催化剂对Suzuki偶联反应的活性和选择性起着决定性的影响,是研究Suzuki偶联反应的关键.对含有膦配体、N-卡宾配体、亚胺配体、胺配体和其它配体的钯配合物催化剂催化效果进行了综述.     

纳米磁性负载氮杂环卡宾配体钯催化剂对溴苯Suzuki偶联反应的催化行为研究

Suzuki反应是合成联苯结构化合物的重要手段，广泛应用于医药、液晶、天然产物合成领域。传统含磷配体催化剂通常存在空气稳定性较差，分离困难等问题。以氯甲基苯乙烯树脂包裹超顺磁性纳米四氧化三铁粒了材料作为载体，表面修饰上大位阻氮杂环卡宾配体，然后与金属钯络合形成磁性负载催化剂。实验结果显示，处对溴代芳烃与苯硼酸的Suzuki偶联反应在用量为5ppm（mol％）时仍有很好的催化作用，循环使用次数可达21次，表明用纳米磁粒予负载卡宾配体制各的钯催化剂是一种高活性、易回收的非均相绿色催化剂。     

六元氮杂环卡宾前体催化剂的合成

以中间体2-(氨基(苯基)次甲基)苯胺和芳基硼酸类化合物为原料,经过Chan-Lam偶联反应,区域选择性地得到中间化合物。再在钯催化条件下,将前一步的中间化合物与含强供电子基团或强吸电子基团的卤代物进行反应,顺利地得到碳氮键偶联产物。之后经过关环,得到两类电性不同的手性六元氮杂环卡宾前体,其结构经~1HNMR、~(13)CNMR、HRMS进行表征,总收率为39%。     

氯代芳烃偶联反应中钯催化剂的研究进展

在合适的钯催化作用下,可将廉价易得、低活性的氯代芳烃应用于C—C键和C杂键形成的偶联反应。对偶联反应用钯催化剂的研究进行了综述。通过选择合适的配体,钯催化剂可有效地催化带有多种体取代基的氯代芳烃或氯代杂芳烃,发生Suzuki、Negishi、Stille和Heck等多种偶联反应,获得较高的收率和很高的选择性。     

双核酰胺官能化NHC—钯(Ⅱ)配合物的合成及催化Suzuki-Miyaura交叉偶联反应研究

以苯并咪唑、对甲基苯胺和氯乙酰氯为原料合成二(1-苯并咪唑基)甲烷和2-氯-N-(p-甲苯基)乙酰胺，并采用溶剂热法制备了一种新型酰胺官能化氮杂环卡宾钯配合物[(amide-NHC)Pd₂Cl₄]。通过PXRD、TGA、FT-IR和SCD对其进行表征。结果表明，目标配合物属于单斜晶系、P2₁/c空间群。将[(amide-NHC)Pd₂Cl₄]配合物应用于Suzuki-Miyaura偶联反应，当催化剂摩尔分数为2%时，催化产率高达98.74%。     

胺烷基二茂铁环钯化反应及其产物催化性能的研究

本文报道了几种新的胺烷基二茂铁的环钯化反应;测试并讨论了环钯化产物的红外光谱、H NMR谱、MS谱和Móssbuuer谱;初步考查了一种产物对交叉偶联反应的催化作用。     

Ni催化Suzuki反应的研究进展

综述了近年来镍催化的Suzuki偶联反应的研究进展。回顾了各类卤代芳香烃、磺酸芳基酯、有机硼等底物参与的Suzuki反应在反应条件方面的改进,随着催化剂、配体、还原剂的活性提高,反应条件越来越温和。比较了镍催化剂与钯催化剂的催化能力,镍催化剂向着稳定、高效、价廉的方向发展,且比钯催化剂适用范围广,是钯催化剂的理想替代品。介绍了新型的含氮杂环卡宾及非均相镍催化剂的发展现状及其特点。     

脲醛树脂固载钯催化剂的制备及催化Suzuki偶联反应的研究

将Pd(OAc)2与2-二苯膦基苯甲醛络合,再与甲醛、尿素缩合反应制备脲醛树脂,得到固载钯催化剂.用固载钯催化剂进行一系列芳基硼酸与芳基卤代物的Suzuki耦联反应.研究结果表明,固载钯催化剂在温和的反应条件下催化合成联苯类化合物,收率＞86％,合成的固载钯催化剂具有良好的重复利用性.     

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。     

Surface Modification of Inorganic Oxide Particles with a Carbene Complex of Palladium: A Recyclable Catalyst for the Suzuki Reaction

The reaction of 1-(2,4,6-trimethylbenzyl)-3-(propyltriethoxysilane)imidazolidinium chloride, with the Pd(OAc)₂ complex proceeded smoothly in DMSO to give the bis[1-(2,4,6-trimethylbenzyl)-3-(propyltriethoxysilane)imidazolidin-2-ylidene]dichloropalladium(II) complex that was grafted onto the surface of amorphous silica. The effects of various factors, such as reaction temperature and time, on the grafting efficiency was evaluated. Inorganic oxide particles that were modified with a carbene complex of palladium(II) were tested for catalytic activity in the Suzuki coupling reaction between phenylboronic acid and several aryl halides.     

An Efficient Palladium‐NHC (NHC=N‐Heterocyclic Carbene) and Aryl Amination Pre‐Catalyst: [Pd(IPr*)(cinnamyl)Cl]

The well‐defined [Pd(IPr*)(cinnamyl)Cl] complex is reported as one of the best N‐heterocyclic carbene (NHC)‐based pre‐catalysts for the Buchwald–Hartwig amination reaction. This catalytic system displays high efficiency for the coupling of numerous (hetero)aryl chlorides, with a wide range of amines, at room temperature or at extremely low catalyst loading (as low as 0.025 mol%).     

Incorporation of a tungsten Fischer-type metal carbene covalently bound to functionalized SBA-15

A metal Fischer carbene [(CO)₅WC(φ)OCH₂CH₃] was covalently linked for the first time to the silanol groups of the mesoporous channels of SBA15 by following two different synthetic anchoring routes. The first one goes through the reaction of the SBA15 mesoporous silica walls functionalized by aminopropyltriethoxysilane (APTES) with a tungsten carbene Wφ, while in the second approach a precursor synthesized by reacting APTES with the carbene Wφ is then anchored via a direct bond to the silanol groups in the interior pore channels of SBA-15.

This tethering is helpful to prevent the decomposition of the metallic complex. XRD, N₂ adsorption–desorption, and TEM analysis provide strong evidence that the mesoporous support structure retains its long-range ordering after the grafting process, despite a significant reduction of its specific surface area, pore-volume and pore-size. The chemical bonding of the tungsten carbene to the silanol groups of SBA-15 materials was studied with solid-state NMR spectroscopy. Both ¹³C MAS NMR and ²⁹Si CP MAS NMR spectra confirm the covalent linking of the carbene to the silica-pore system.     

Catalytic Carbon‐Fluorine Bond Activation with Monocoordinated Nickel‐Carbene Complexes: Reduction of Fluoroarenes

Monocoordinate nickel/N‐heterocyclic carbene complexes reveal unexpected reactivity towards aryl fluorides. Defluorination reactions were efficiently performed with a β‐hydrogen‐containing alkoxide (3 equiv.) in the presence of 3 mol % of [1:1] Ni(0)/IMes⋅HCl catalyst (IMes=1,3‐dimesitylimidazol‐2‐ylidene).     

Syntheses, structures and catalytic activities of ruthenium (II) carbonyl iodide complexes with CNC-pincer bis (carbene) ligand

Two new pincer bis (carbene) ligands and corresponding ruthenium (II) carbonyl iodide complexes have been synthesized and characterized. The structures of complexes 3 and 4 have been determined by X-ray crystallography. Complexes 3 and 4 have been proved to be efficient catalysts in the transfer hydrogenation of acetophenone.     

Synthesis, characterization and catalytic properties of an N-heterocyclic carbene palladium-based complex

A palladium(II) complex, bis[1,3-bis-(2,4,6-trimethylbenzyl)benzimidazol-2-ylidene]palladium(II) chloride, Pd(NHC), bearing N-heterocyclic carbenes has been synthesized and characterized by elemental analysis, IR spectroscopy and ¹H and ¹³C NMR spectroscopy. Crystal structure details of Pd(NHC) are also presented. The palladium centre in the complex lies on a crystallographic inversion centre and occupies a square-planar environment, with both chloride and N-heterocyclic carbene ligands adopting a trans arrangement with Cl–Pd–Cl and C–Pd–C angles are precisely 180°. The palladium–carbene complex was tested as a catalyst in the Suzuki–Miyaura cross-coupling reaction.     

Carbenes Made Easy: Formation of Unsymmetrically Substituted N‐Heterocyclic Carbene Complexes of Palladium(II), Platinum(II) and Gold(I) from Coordinated Isonitriles and their Catalytic Activity

From palladium(II) or platinum(II) bis(isonitrile) complexes and from gold(I) isonitrile complexes, both easily available from simple precursors, the corresponding mono‐N‐heterocyclic carbene (NHC) complexes could be obtained selectively in good yields under very mild conditions. The reagents are simple β‐chloroammonium salts in the presence of a weak base. Unsymmetric NHC complexes are accessible. Thus over only two steps from simple metal precursors a broad variety of NHC complexes is available, the method is ideal to quickly assemble catalyst libraries. The palladium complexes are active pre‐catalysts in Suzuki cross‐coupling even with the additional isonitrile ligand on palladium.     

一种吡嗪酯类香料前体的制备及其热性能

为开发吡嗪酯类香料前体,以2,5-二甲基吡嗪氮氧和丙烯酸噻吩甲酯为原料,在醋酸钯的催化下经偶联反应,合成3-(3,6-二甲基-吡嗪氮氧-2-基)丙烯酸噻吩甲酯目标化合物,通过1H NMR、13C NMR、IR、HRMS表征其结构,并采用热重-微分热重（TG-DTG）和热裂解-气相色谱/质谱法（Py-GC/MS）测其热性能。结果表明：目标化合物从170 oC开始降解,主要热失重区间为170 oC~875 oC,在257 oC失重速率最大,总失重为76.5%。在300 oC~900 oC的有氧和无氧裂解氛围下,共鉴定出11种挥发性产物,主要有烷基吡嗪类、2-甲基噻吩、2-噻吩甲醇等特征香味物质,有氧氛围下热裂解产物种类较多,相对含量较高。依据主要裂解产物的种类及相对含量的变化,初步揭示了裂解机理。目标化合物在单料烟中的最适宜添加量为2 mg/kg。     

Syntheses and Properties of Metal Containing Polyimides Based on the Gold Carbene Complex

A novel gold carbene complex, bis(1,3-di-p-dimethylaminobenzylimidazolidinylidene) gold(I), was synthesized and polymerized to polyimides in a one-step method with various aromatic dianhyrides. The gold-coordinated polyimides are characterized by IR and NMR (¹H, ¹³C) spectroscopy. The materials have inherent viscosities that range from 1.88 to 2.39 dl/g and show excellent solubility in N-methylpyrrolidone and N,N-dimethylacetamide. The glass transition temperatures of the coordinated polyimides range from 203–265°C and a 5% weight loss in air is observed from 535–578°C. The polymers form dark yellow, tough films that are transparent above 365 nm. The effect of different flexible units on the properties of the polyimides is discussed.     

Poly(aryl ether oxadiazoles)

A general method for the preparation of poly(aryl ether oxadiazoles) has been developed where the generation of an aryl ether linkage was the polymer-forming reaction. Two synthetic approaches were investigated based on either an oxadiazole-activated halo displacement with phenoxides or a hydrazide-activated halo-displacement with phenoxides. The hydrazide may be subsequently thermally cyclodehydrated to the oxadiazole heterocyclic. In each case, the negative charge developed in the transition state could be stabilized through a Meisenheimer Complex, analogous to conventional activating groups (e.g., sulfone and ketone), and the electron affinity, as judged by ¹H NMR, was comparable to that of other activating groups. An appropriately substituted diarylfluoro oxadiazole was prepared and polymerized with various bisphenols in an NMP/CHP solvent mixture in the presence of K₂CO₃. High molecular weight poly(aryl ether oxadiazoles) were synthesized with viscosities ranging from 0.44 to 0.76 dL/g and Tg's in the 200°C range. Conversely, the hydrazide activated halo-displacement as a means of preparing poly(aryl ether hydrazides) was not as successful, since it appears that the hydrazide was of sufficient acidity to form a salt with K₂CO₃ preventing solubility and polymerization.