担载三核羰基钴簇的合成,表征和烯烃氢甲酰化反应

通过配体交换反应合成了膦化硅胶担载的羰基钴簇配合物(Si)—PPh_2[BrCCo_3(CO)_(9-2)],用IR、XPS和DPS对其结构进行了表征,并测得了担载簇配合物的金属含量,研究了担载簇(Si)—PPh_2[BrCCo_3(CO)_(9-2)]在烯烃氢甲酰化反应中的催化活性.结果表明,担载的三核羰基钴簇可达到与均相三核钴簇基本一致的反应活性,在一定的反应条件下,烯烃转化率和醇醛收率均在85％以上,有很少量的加氢产物生成。     

铑膦配合物的加压原位核磁氢谱研究

在近似工业反应条件下(H2/CO=1:1, 1.0MPa, 70℃), 应用加温加压原位核磁共振技术, 考察了铑膦配合物催化剂HRh(CO)(PPh3)3-PPh3体系的烯烃醛化反应。结果表明,在烯烃醛化反应条件下, 反应液中存在羰基氢化铑中间配合物, 并在^1H NMR获得了该配合物中Rh-H键的质子讯号。     

[Ph(Me3Si)N]3Yb(THF)的合成及其催化Tischenko反应的研究

通过无水YbCl3和Ph[(CH3)3N]Li在四氢呋喃中反应,合成了目标化合物[Ph(Me3Si)N]3Yb(THF),该化合物经过元素分析,红外光谱以及X单晶结构表征.研究表明该配合物以较高活性催化芳醛的Tischenko反应.     

二羰基水杨醛肟铑配合物催化的苯乙烯常压氢甲酰化反应

用Rh~2(CO)~4Cl~2与水杨醛肟的钠盐反应合成了二羰基水杨醛肟铑配合物Rh(sox)(CO~2)(1)。在常压下研究了该配合物与膦或亚磷酸酯组成的体系对苯乙烯氢甲酰化反应的催化性能, 此体系对烯烃没有催化加氢作用, 产物醛的化学选择性均为100%。考察了膦的结构与用量对催化活性和选择性的影响, 双膦作配体时活性和选择性都高于单膦, 其中Rh(sox)(CO)~2-Ph~2P(CH~2)~3PPh~2体系的最高初活性(TON)可达1.60min^-^1, 2-苯基丙醛的选择性在90%以上。对反应的活性物种作了初步讨论。     

多核铑原子簇络合物的结构稳定性和醛化活性

合成了十二羰基四铑和十六羰基六铑,证明两者都是很活泼的烯烃醛化催化剂。用红外光谱测定了醛化反应前后的铑原子簇的稳定性,结果表明Rh_4(CO)_12在醛化条件下不稳定,转变成Rh_6(CO)。考察了强σ~-给电子配位体三苯基磷对簇分子骨架稳定性的影响,表明Rh_4(CO)_(13)原子簇骨架在醛化反应条件下已被打破,并转变成单核分子碎片,而Rh_6(CO)_16在此条件下是比较稳定的,上述两种铑簇化合物与单核络合物RhCl(CO)(PPh_3)_2对烯烃醛化具有相同的表观反应速度。     

担载金属簇——Ⅰ.硅胶化学键联羰基钴簇YCCo_3(CO)_9催化剂

羰基钴簇络合物YCCo_3(CO)_9,是一种具有良好醛化活性的均相催化剂。本文报导将它化学键联到硅胶表面上而固相化,及其醛化反应评价结果。首先由C_2H_3Si(EtO)_3合成CCl_3C_2H_4Si(EtO)_3,然后将此化合物与硅胶表面键联。生成三氯化物,再与八羰基二钴反应而制得负载型催化剂,其钴含量为6～7％。测定了此负载型催化剂的红外光谱,评价其对庚烯-1的醛化反应活性。发现在140℃,40公斤/厘米~2压力的较佳反应条件下,6小时内,庚烯-1转化率为83％,而醇醛选择性92％。此外还进行了多次循环使用试验,但其钴流失似仍过大。     

钴、镍与α-萘乙酸配合物的合成与表征

近年来 ,有关具有生物活性的配体与金属离子的固体配合物的研究引起了人们的重视 [1～ 3 ] 。α-萘乙酸 ( HL)是一种重要的植物激素 ,由于 α-萘乙酸难溶于水常制成盐使用。铜、锌及稀土等与α-萘乙酸的固体配合物已得到研究 ,它们均难溶于水 [2 ,3 ] 。由于钴、镍是植物体的重要营养元素 ,而钴、镍与α-萘乙酸的二元固体配合物及钴、镍与α-萘乙酸和α-呋喃甲醛肟 ( L')的三元固体配合物未见有报道 ,我们对此作了一些研究。1　配合物的合成按文献 [4 ]用 Co Cl2 、Ni Cl2 和 Na HCO3 反应制得 Co CO3 、Ni CO3 ,干燥后取过量 Co CO…     

螯合型羰基铑配合物催化甲醇羰基化反应的机理研究

报道了螯合型正方平面羰基铑配合物催化甲醇羰基化反应的机理研究. 通过含有两种与铑具有不同配位能力的授体的配体, 与四羰基二氯二铑形成螯合型正方平面阳离子配合物. 研究证明, 该类配合物在催化甲醇羰基化反应过程中, 其活性物种区别于文献报道的[Rh(CO)2I2]－阴离子. 配合物中铑与吡啶环上共轭N形成的N→Rh配键, 在羰基化反应过程中并非通常认为的断裂而是形成新的活性物种, 即配体与铑作为整体参与了CH3I的氧化加成及CH3COI的生成过程. 通过对相应的聚合物配体铑催化剂的研究, 进一步证实了这个反应机理. 这一结果, 对该类催化剂分子设计, 以及克服其工业使用中的催化剂沉淀失活等现象均有重要意义.     

SiO2负载的Pt-M(M=Cr,Mo,W)配合物双功能催化剂

过渡金属异双核金属有机化合物的研究是一个活跃的领域,人们期望从中制取对极性小分子(如CO,CO2等)具有双功能活化的催化剂.周期表前区过渡金属或稀土元素(如Ti,Zr,Mo,La,Ce等)作为添加组分可明显地增加SiO2负载的铑催化剂催化CO氢化反应的活性和含氧化合物的选择性[1].虽然一些异双核金属氢基羰基化合物已被合成和表征[2],但是关于SiO2负载的异双核金属配合物催化剂的研究还未见文献报道.我们合成、表征了(PPh3)HPt(μ-PPh2)(μ-CO)M(CO)4(M=Cr,Mo,W)异双核配合物[3](I).本文研究了SiO2负载的该配合物催化剂对CO氢化反应和对丙烯氢甲酰化反应的两种催化功能.     

含异硫氰酸苯酯裂解碎片的铁硫羰合簇取代衍生物的合成与表征

近年来 ,金属羰基化合物与异硫氰酸苯酯 Ph NCS反应曾有过报道 [1 -3 ] ,但反应条件各异 ,多半得到一取代产物。本文用 Fe3 (CO) 1 2 与 Ph NCS在温和条件下缓慢反应 ,除了得到一取代产物外 ,还得到一个新的二取代产物。通过元素分析、IR、MS、1 H NMR、1 3 C NMR和 X- ray四园衍射表征 ,确定它们的化学式为 Fe3 (CO) 8(CNPh) (μ3 - S) 2 ( )和 Fe3 (CO) 7(CNPh) 2 (μ3 - S) 2( )。实　验　部　分合成采用 Schlenk技术在氮气保护下进行 ,所使用溶剂经过脱气脱水处理。一 .簇合物的合成0 .5 g(1.0 mmol) Fe3 (CO) 1 2 和 …     

Synthesis,characterization and catalytic,cytotoxic and antimicrobial activities of two novel cyclotriphosphazene‐based multisite ligands and their Ru(II) complexes

Two novel cyclotriphosphazene ligands ( 2 and 3 ) bearing 3‐oxypyridine groups and their corresponding Ru(II) complexes ( 4 and 5 ) were synthesized and their structures were characterized using Fourier transform infrared, ¹H NMR and ³¹P NMR spectroscopic data and elemental analysis. The Ru(II) complexes were used as catalysts for catalytic transfer hydrogenation of p‐substituted acetophenone derivatives in the presence of KOH. Additionally, the cytotoxic activities of compounds 2 , 3 , 4 , 5 were evaluated against PC3 (human prostate cancer), DLD‐1 (human colorectal cancer), HeLa (human cervical cancer) and PNT1A (normal human prostate) cell lines. Finally the antimicrobial activities of compounds 2 , 3 , 4 , 5 were evaluated against a panel of Gram‐positive and Gram‐negative bacteria and yeast cultures. The complexes showed efficient catalytic activity towards transfer hydrogenation of acetophenone derivatives, especially those bearing electron‐withdrawing substituents on the para‐position of the aryl ring. The compounds were found to have moderate to high cytotoxic and antimicrobial activities, and Ru(II) complexation enhanced both cytotoxic and antimicrobial activities in comparison with the parent compounds. Copyright © 2015 John Wiley & Sons, Ltd.     

Ansa-bridged eta5-cyclopentadienyl molybdenum and tungsten complexes: synthesis, structure and application in olefin epoxidation

Ansa-bridged eta(5)-cyclopentadienyl molybdenum and tungsten tricarbonyl complexes of formula [M(eta(5)-C(5)H(4)(CH(2))(3)-eta(1)-CH(2))(CO)(3)] (M=Mo or W) were synthesized and the X-ray crystal structure of the tungsten complex is reported. In the epoxidation of cyclooctene the molybdenum compound shows a high catalytic activity, approaching the observed activities for the most reactive unbridged complexes of composition CpMo(CO)(3)X (X=Cl, CH(3)). The activity of the tungsten complex is also amongst the highest catalytic activities for the olefinic epoxidation of complexes with the composition CpW(CO)(3)X and WO(2)X(2)L(2), reported so far. The low ring strain of the ansa-bridged system improves the stability of the complexes under oxidative conditions considerably in comparison to derivatives with a shorter bridge and therefore paves the way to introduction of chirality in these systems.     

Carbonates, thiocarbonates, and the corresponding monoalkyl derivatives. 1. Their preparation and isotropic (13)C NMR chemical shifts

Three series of potassium carbonate and thiocarbonate salts were synthesized, and the corresponding (13)C isotropic solid-state NMR and the aqueous solution (13)C and (1)H NMR data were collected. The series of compounds that were studied consists of (1) the parent compounds, i.e., potassium carbonate, K(2)CO(3), potassium hydrogen carbonate, KHCO(3), potassium monothiocarbonate, K(2)CO(2)S, potassium dithiocarbonate, K(2)COS(2), and potassium trithiocarbonate, K(2)CS(3), (2) the oxygen monoalkyl substituted derivatives of the parent compounds (OR series), i.e., three potassium O-alkylcarbonates, KO(2)COR, three potassium O-alkylmonothiocarbonates, KOSCOR, and three potassium O-alkyldithiocarbonates, KS(2)COR, all with R = CH(3), CH(2)CH(3), CH(CH(3))(2), and (3) the sulfur monoalkyl substituted derivatives of the parent compounds (SR series), i.e., two potassium S-alkylmonothiocarbonates, KO(2)CSR; two potassium S-alkyldithiocarbonates, KOSCSR, and two potassium S-alkyltrithiocarbonates, KS(2)CSR, all with R = CH(3) or CH(2)CH(3). The preparation and proper characterization of KO(2)CSR and KOSCSR with R = CH(3) and CH(2)CH(3) along with new IR and X-ray powder diffraction data for several other compounds in the series are reported for the first time in this study. Solution NMR data for KO(2)CSR (R = CH(3), CH(2)CH(3)) and KOSCSR (R = CH(3)) and solid-state NMR data for K(2)CO(2)S and K(2)COS(2) could not be obtained because they are unstable under the corresponding measurement conditions. The isotropic chemical shift values of the central carbon atoms obtained from solid-state MAS (magic angle spinning) NMR experiments deviate at most by 3 ppm from the corresponding solution values. Two major trends in the (13)C chemical shift values of the central carbon atoms were found. First, if an oxygen atom in a parent compound or in an alkyl-substituted derivative is replaced by a sulfur atom, a significantly higher chemical shift value is observed. This trend is discussed in terms of the paramagnetic contribution to the chemical shielding constant. Second, the size of the alkyl group in the monoalkyl derivatives has a very small effect on the chemical shift values of the central carbon atoms. This observation is explained using the concept of varying inductive effects produced by alkyl groups. The trends observed for the (13)C and (1)H chemical shift values of the alkyl groups follow common concepts on the structure dependency of chemical shifts.     

Cu掺杂对LaMnO3催化剂的结构和催化氧化性能的影响

采用非晶态多核配合的方法合成了La1-xCuxMnO3(x=0、0.05、0.1、0.2、0.3、0.4、0.5)系列催化剂, 并用X射线衍射(XRD)、透射电镜(TEM)、比表面测定仪(BET)等手段对催化剂的微观结构进行了表征. 研究了Cu掺杂对钙钛矿结构及其对CO催化氧化发光性能及催化氧化CO、CH4性能的影响规律. 结果表明, 当x≤0.1 时, Cu掺杂仍可形成单相的钙钛矿结构; 当x>0.1时, 过量掺杂的Cu以CuO杂相存在. Cu掺杂可改善La1-xCuxMnO3催化剂对CO和CH4的催化氧化活性. 经700 ℃焙烧3 h制备的La0.9Cu0.1MnO3催化剂具有最高CO催化氧化活性(T100%=170 ℃), 该结果与CO催化氧化发光结果一致.而La0.95Cu0.05MnO3催化剂对CH4的催化氧化活性最高(T95%=705 ℃).     

一枝蒿酮酸酰胺衍生物的合成和抗A3, B型流感病毒和 单纯I, II型疱疹病毒活性研究

从新疆一枝蒿中分离得到了单体化合物一枝蒿酮酸, 然后以一枝蒿酮酸和有机胺为原料, 在偶联剂DCC, HOBt/DMAP的作用下, 合成了13种未见文献报道的一枝蒿酮酸酰胺衍生物2a～2m. 所合成的化合物经过IR, 1H NMR, ESI-MS等分析方法进行了表征, 并对化合物2a～2m进行初步的体外抗A3, B型流感病毒和单纯I, II型疱疹病毒活性研究. 初步试验结果表明化合物2a同时具有抗A3, B型流感病毒活性, 而且抗B型流感病毒活性比母体化合物的活性较高. 化合物2d的抗B型流感病毒活性比母体化合物高16倍, 化合物2e同时具有较强的抗单纯I, II型疱疹病毒活性.     

Design,Synthesis, Inhibiting HDACs Ability and Antitumor Activity of Pyrimidin-4(3H)-one Hydroxamate Derivatives

A series of novel pyrimidin-4(3H)-one hydroxamate derivatives was designed, synthesized and studied for their activities against histone deacetylases(HDACs). The results indicate that all the compounds show HDACs inhibitiory activity. The antiproliferative activities of the compounds against HeLa and A549 cells were also investigated. The pharmacological results show compound 9g has potent activity in the enzymatic inhibition assay and cell-based assay.     

Iridium-catalyzed transfer hydrogenation of alpha,beta-unsaturated and saturated carbonyl compounds with 2-propanol.

The selective transfer hydrogenation of alpha,beta-unsaturated carbonyl compounds to saturated ones was achieved by the use of 2-propanol as a hydrogen donor under the influence of catalytic amounts of [Ir(cod)Cl](2), 1,3-bis(diphenylphosphino)propane (dppp), and Cs(2)CO(3). Thus, a variety of conjugated enones were allowed to react with 2-propanol in the presence of the [Ir(cod)Cl](2)/dppp/Cs(2)CO(3) system to give the corresponding saturated carbonyl compounds in good to excellent yields without formation of allylic alcohols. Both dppp and Cs(2)CO(3) were essential components to achieve the reduction satisfactorily. Additionally, the reduction of carbonyl compounds to alcohols was also promoted by the same catalytic system. When the reaction of a 1:1 mixture of a conjugated ketone and a saturated ketone with 2-propanol was carried out in the presence of [Ir(cod)Cl](2) combined with dppp and Cs(2)CO(3), the reduction of the alpha,beta-unsaturated ketone was found to take place in preference to that of the saturated ketone.     

Synthesis, characterization and structures of 2-(3,5-dimethylpyrazol-1-yl)ethylseleno derivatives and their probable glutathione peroxidase (GPx) like activity

A series of 2-(3,5-dimethylpyrazol-1-yl)ethylseleno derivatives has been synthesized. The glutathione peroxidase like catalytic activity of these compounds has been studied in a model system, in which reduction of hydrogen peroxide with dithiothreitol (DTT(red)), in the presence of an organoselenium compound was investigated by (1)H NMR spectroscopy. All these compounds exhibit GPx like catalytic activities and the catalytic reaction proceeds through a selenoxide intermediate, identified by (77)Se{(1)H} NMR spectroscopy.     

Promiscuity of carbonic anhydrase II. Unexpected ester hydrolysis of carbohydrate-based sulfamate inhibitors

Carbonic anhydrases (CAs) are enzymes whose endogenous reaction is the reversible hydration of CO(2) to give HCO(3)(-) and a proton. CA are also known to exhibit weak and promiscuous esterase activity toward activated esters. Here, we report a series of findings obtained with a set of CA inhibitors that showed quite unexpectedly that the compounds were both inhibitors of CO(2) hydration and substrates for the esterase activity of CA. The compounds comprised a monosaccharide core with the C-6 primary hydroxyl group derivatized as a sulfamate (for CA recognition). The remaining four sugar hydroxyl groups were acylated. Using protein X-ray crystallography, the crystal structures of human CA II in complex with four of the sulfamate inhibitors were obtained. As expected, the four structures displayed the canonical CA protein-sulfamate interactions. Unexpectedly, a free hydroxyl group was observed at the anomeric center (C-1) rather than the parent C-1 acyl group. In addition, this hydroxyl group is observed axial to the carbohydrate ring while in the parent structure it is equatorial. A mechanism is proposed that accounts for this inversion of stereochemistry. For three of the inhibitors, the acyl groups at C-2 or at C-2 and C-3 were also absent with hydroxyl groups observed in their place and retention of stereochemistry. With the use of electrospray ionization-Fourier transform ion cyclotron resonance-mass spectrometry (ESI-FTICR-MS), we observed directly the sequential loss of all four acyl groups from one of the carbohydrate-based sulfamates. For this compound, the inhibitor and substrate binding mode were further analyzed using free energy calculations. These calculations suggested that the parent compound binds almost exclusively as a substrate. To conclude, we have demonstrated that acylated carbohydrate-based sulfamates are simultaneously inhibitor and substrate of human CA II. Our results suggest that, initially, the substrate binding mode dominates, but following hydrolysis, the ligand can also bind as a pure inhibitor thereby competing with the substrate binding mode.     

Essays on organometallic chemistry, VII. Laboratory curiosities of yesterday, catalysts of tomorrow: organometallic oxides

A systematic investigation of organorhenium- and organoosmium oxides, following the initial discovery of trioxo(η⁵-pentamethylcyclopentadienyl)rhenium(VII) in 1984 by Herrmann, Serrano and Bock, has yielded a plethora of high-oxidation-state organometallics. The key compound methyltrioxorhenium(VII) is now easily accessible and has displayed a surprisingly broad range of catalytic activities, most notably in olefin metathesis, olefin epoxidation, and aromatic oxidation (vitamin K₃). In this context, general problems related to synthesis and reactivity, to structure and bonding, as well as to thermal and photochemical stability were tackled and solved. Organometallic oxides can also serve as structurally well-defined molecular or polymeric precursor compounds for the synthesis of inorganic oxides, the formation of rhenium trioxide being the first example to result from the polymer route.