首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
A series of nickel(II) and cobalt(II) complexes, NiX2L (X = Cl, Br; 1-6) and CoCl2L (7-9), with 2,9-diaryl-1,10-phenanthroline ligands (L1-L3) have been synthesized and characterized by elemental analysis, UV-Vis, IR spectroscopy, and X-ray crystal structural study (for 1, 4-7, 9). The solid-state structures of 1, 5-7 and 9 show four-coordinate, slightly flattened tetrahedral geometry at the Ni(II) or Co(II) center, while 4 is five-coordinated (square-pyramidal), containing a THF molecule as an auxiliary ligand. The title complexes (1-9) display good catalytic activities in ethylene oligomerization when activated with methylaluminoxane (MAO). While the Co(II) precatalysts produce primarily C4 isomers, the Ni(II) complexes give ethylene dimers and trimers at normal pressure. The activities and yields of linear α-olefins increase with increasing ethylene pressure for the Ni(II) complexes, leading to more high-molar-mass products (C8-C18). Complex 6 displays the best catalytic activity among the complexes studied (up to 1518 kg/mol[Ni] h at 10 atm).  相似文献   

2.
The electrochemical properties of cationic complexes [(η6-arene)Ru(N ∩ N)Cl]Cl (arene/N ∩ N = C6H6/1,10-phenanthroline (1), p-MeC6H4Pri/1,10-phenanthroline (2), C6Me6/1,10-phenanthroline (3), C6Me6/5-NO2-1,10-phenanthroline (4), and C6Me6/5-NH2-1,10-phenanthroline (5)) were studied by cyclic voltammetry in order to rationalize catalytic activity in transfer hydrogenation of the respective aqua complexes [(η6-arene)Ru(N ∩ N)(OH2)](BF4)2 (6-10). Complexes 1-5 were chosen because the ‘true’ catalysts 6-10 are unstable under the conditions of the measurement. The electrochemical behaviour of 1-5 in acetonitrile solution is rather complicated due to consecutive and parallel chemical reactions that accompany electron transfer processes. Nonetheless, interpretation of the electrochemical data allowed to assess the influence of the structure and substitution on the redox and catalytic properties: the catalytic ability correlates with the reduction potentials, indicating the decisive role of the η6-arene ring directly bonded to the catalytic centre (Ru).  相似文献   

3.
The complexes [Pd(acac)2] 1, [Pd(hfa)2] 2 (hfa = hexafluoroacetylacetonate), [Pd(CF3CO2)2] 3 and [Pd3(CH3CO2)6] 4 exhibit very different catalytic efficiency in the reaction between secondary amines and activated alkenes. Complexes 1 and 4 generally show an enhanced activity when catalytic amounts of NH4X salts (X = low-coordinating anion) are added to the reaction mixtures. On the contrary, the activity of the perfluorurate analogues 2 and 3, which is much higher than that of 1 and 4, is generally scarcely affected by the presence of the NH4X additive. The cocatalytic effect of NH4X is comparable with that of strong acids such as CF3SO3H. The ammonium salts alone can behave as a catalyst giving an almost quantitative yield of the hydroamination product.  相似文献   

4.
A series of di-NHC ligands with alkyl bridges of different chain lengths (n = 2-4) and their bi-palladium complexes (4, 5 and 6) have been prepared. The molecular structure of 4 and 6 were determined by X-ray diffraction studies. The structures of complex 4 consist of two pseudo-square-planar subunits in a trans configuration, however 6 consist of two subunits in a cis configuration with π-π stacking between two pyridines. The influence of the different bridges on the structure and reactivity of the complexes has been studied. The catalytic activity of the new binuclear palladium complexes was successfully tested in the Mizoroki-Heck reaction of styrene with bromobenzene. The complex with 2 and 4 carbon linker gave higher yield, while the one with 3 carbon linker gave better regioselectivity.  相似文献   

5.
The activity of homobimetallic ruthenium alkylidene complexes, [(p-cymene)Ru(Cl)(μ-Cl)2Ru(Cl)(CHPh)(PCy3)] [Ru-I] and [(p-cymene)Ru(Cl)(μ-Cl)2Ru(Cl)(CHPh)(IPr)] [Ru-II], on intermolecular [2+2+2] cyclotrimerisation reactions of monoynes has been investigated for the first time. It was found that these complexes can catalyse the chemo and regioselective cyclotrimerisation reactions of alkynes at both 25 and 50 °C in polar, aprotic solvents. The catalytic activity of [Ru-I] and [Ru-II] was compared to other well-known ruthenium catalysts such as Grubbs first generation catalyst [RuCl2(CHPh)(PCy3)2] [Ru-III], [RuCl(μ-Cl)(p-cymene)]2 [Ru-IV] and [RuCl2(p-cymene)PCy3] [Ru-V] complexes. To examine the effect of the steric hinderance of substrates on the regioselectivity of the reaction, a series of sterically hindered silicon containing alkynes (1a, 1b, 1c) were used. It was shown that the isomeric product distribution of the reaction shifts from 1,2,4-trisubstituted arenes to 1,3,5-trisubstituted arenes as the steric hinderance on the substrates increases. These homobimetallic ruthenium alkylidene complexes also catalysed regio- and chemo-selective cross-cyclotrimerisation reactions between silicon-containing alkynes (1a, 1b, 1c) and aliphatic alkynes (1d-g).  相似文献   

6.
Two new mixed ligand silver(I) complexes of formulae {[Ag(tpp)3(asp)](dmf)} (1) (aspH = o-acetylsalicylic acid and tpp = triphenylphosphine) and [Ag(tpp)2(o-Hbza)] (2) (o-HbzaH = o-hydroxy-benzoic acid) were synthesized and characterized by elemental analyses, spectroscopic techniques and X-ray crystallography at ambient conditions. Three phosphorus and one carboxylic oxygen atoms from a de-protonated aspirin ligand in complex 1 and two phosphorus and two carboxylic oxygen atoms from a chelating o-Hbza anion in complex 2 form a tetrahedral geometry around Ag(I) ions in both complexes.Complexes 1 and 2 and the silver(I) nitrate, tpp, aspNa and o-HbzaH were tested for their in vitro cytotoxic activity against leiomyosarcoma cells (LMS), human breast adenocarcinoma cells (MCF-7) and normal human fetal lung fibroblasts (MRC-5) cells with Thiazolyl Blue Tetrazolium Bromide (MTT) assay. For both cell lines 1 and 2 were found to be more active than cisplatin. Additionally, 1 and 2 exhibit lower activity on cell growth proliferation of MRC-5 cells. The type of LMS cell death caused by 1 and 2 were evaluated in vitro by use of flow cytometry assay. The results show that at concentrations of 1.5 and 1.9 μΜ of complex 1, 44.1% and 69.4%, respectively of LMS cells undergo programmed cell death (apoptosis). When LMS cells were treated with 1.6 and 2.3 μM of 2, LMS cells death was by 29.6% and 81.3%, respectively apoptotic. Finally, the influence of the complexes 1 and 2, upon the catalytic peroxidation of linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase (LOX) was kinetically and theoretically studied. The binding of 1 and 2 towards LOX was also investigated by Saturation Transfer Difference (STD) 1H NMR experiments.  相似文献   

7.
New nickel(II) complexes with macrocyclic ligands bearing benzyloxy [(5), (9)], 2-methylbenzyloxy (7), 3-methylbenzyloxy (8), and hydroxy (6) groups on the pyridine ring have been synthesized. Structures of the hydroxy substituted macrocyclic ligand (L-OH·3HCl·H2O), and the benzyloxy substituted ligand (L-OBn·3HCl) and its nickel(II) complex (5), as well as an analogous Ni(II) complex (8), have been revealed by X-ray crystallography. Their catalytic capabilities in the reductive debromination of 1-bromo-4-tert-butylbenzene have been elucidated, which has revealed that the pyridine ring can be a suitable position for the introduction of functional groups while maintaining the catalytic capabilities of the nickel(II) complexes.  相似文献   

8.
Several mononuclear copper complexes 1(a-b) and 2(a-b) supported over sterically demanding [NNO] ligands namely, N-(aryl)-2-[(pyridin-2-ylmethyl)amino]acetamide [aryl = 2,6-diethylphenyl (1) and mesityl (2)], exhibit catecholase-like activity in performing the aerial oxidation of 3,5-di-t-butylcatehol (3,5-DTBC) to 3,5-di-t-butyl-catequinone (3,5-DTBQ) under ambient conditions. The 1(a-b) and 2(a-b) complexes were directly synthesized from the reaction of the respective ligands 1-2 with CuX2·nH2O (X = Cl, NO3, n = 2, 3) in 55-85% yield. Mechanistic insights on the catalytic cycle as obtained by density functional theory studies for a representative complex 1a suggest that an intramolecular hydrogen transfer, from a catechol-OH moiety to a copper bound superoxo moiety, form the rate-determining step of the oxidation process, displaying an activation barrier of 18.3 kcal/mol (ΔG) [6.9 kcal/mol in Δ(PE + ZPE) scale].  相似文献   

9.
Two series of five membered heterocyclic bis(1,3,4-oxadiazole) derivatives 2(a-h) and 3,5-bis(substituted)pyrazoles, isoxazoles 3(a,b,d-i), 4(a-c) were synthesized via oxidative cyclization of some diaroylhydrazones using chloramine-T and cyclocondensation reaction with hydrazine hydrate and hydroxylamine hydrochloride, respectively. The newly synthesized compounds were screened for antioxidant and anti-microbial activities. Compounds 2(b), 3(b), and 4(a) showed higher antioxidant activity at 10 μg/ml while compounds 2(a), 3(a), 3(f), and 4(a) exhibited better anti-microbial activity at 100 μg/ml compared with standard vitamin C and ciprofloxacin, respectively. Structures of newly synthesized compounds were confirmed by elemental analysis and spectral IR, 1H NMR, and 13C NMR data.  相似文献   

10.
Condensation of 1,2,3,4,6-penta-O-acetyl-á-l-idopyranose (1) with phenol yielded phenyl 2,3,4,6-tetra-O-acetyl-α- (2) and α-l-idopyranoside (4). Deacetylation of 2 and 4 afforded phenyl α and β-l-idopyranosides (3 and 5), respectively, the structures of which were verified by periodate oxidation studies. A platinum-catalyzed oxidation of 3 and 5 produced the amorphous phenyl α- and β-L-idopyranosiduronic acids (9 and 11), respectively, which were isolated as the crystalline cyclohexylammonium salts. Phenyl β- and α-d-glucopyranosiduronic acids are apparent minor byproducts of the catalytic oxidations, resulting from an inversion at C-5. p-Nitrophenyl α-d-mannopyranosiduronic acid and p-nitrophenyl α- and β-d-galactopyranosiduronic acids are also described.  相似文献   

11.
Two new withanolides, philadelphicalactone C (1) and philadelphicalactone D (4), along with the known withaphysacarpin (3), ixocarpanolide (5), philadelphicalactone A (6), and ixocarpalactone A (7) were isolated from the aerial parts of Physalis philadelphica Lam. Structures of these compounds were determined by spectroscopic analyses and that of philadelphicalactone C (1) was confirmed by X-ray crystallographic analysis. Evaluation of the cytotoxic activity of all isolates and the derivative 2 against a panel of human cancer cell lines indicated a potent activity of compounds 2, 3, 6, and 7.  相似文献   

12.
The objective was to prepare mononuclear, binuclear, and insoluble polynuclear oxovanadium(IV)-Schiff base complexes and to use them for sulfoxidation and epoxidation of organic substrates. [VO(salen)] (complex 1) with tetradentate salen(salicylideneethylenediamine) being coordinated in the equatorial plane of oxovanadium(IV), [VO(salap)] (complex 2), and [(VO)2(sal2-dhdabp)] (complex 3) with tridentate salap(salicylideneorthoaminophenol) and sal2-dhdabp(salicylidene-3,3-dihydroxy-4,4-diaminobiphenyl) being bound, respectively, in the equatorial plane, of which polynuclear complexes were constituted as monomer units, were prepared and spectroscopically characterized. A sulfide and olefins were oxidized by use of complexes 1 and 2 (mononuclear), complex 3 (binuclear), and the polynuclear complexes (poly-1 and poly-3) synthesized with 1 and 3, respectively. The reaction rates for poly-1 and -3 were a little lower than those of the corresponding 1 and 3. On oxidation of sulfides, poly-3 exhibited lowering of activity by about 15% in three cycles, while poly-1 showed significant lose of activity with each use. Poly-3 was efficient for the oxidation of the olefins only in the first cycle. It was suggested that the loss of activity depends not only on the coordination geometry of the oxovanadium complex, but also on the kind of the substrate.  相似文献   

13.
Thirteen new 2-pyrazoline derivatives bearing benzenesulfonamide moiety (2a-m) were synthesized by condensing appropriate chalcones with 4-hydrazinonbenzenesulfonamide hydrochloride and tested for anticancer and anti-inflammatory actions. According to the protocol of the National Cancer Institute (NCI) in vitro disease-oriented human cells screening panel assay compounds 2b, 2c, 2e, 2f and 2g exhibited considerable antitumor activities against the entire tested tumor cell lines and showed effective growth inhibition GI50 (MG-MID) values of 2.63, 2.57, 6.61, 3.31 and 2.57 μM, respectively, beside a cyclostatic activity TGI (MG-MID) 9.54, 8.51, 24.0, 19.9 and 8.71 μM, respectively. Two compounds 2g and 2k showed more potent anti-inflammatory activity than celecoxib at 5 h in carrageenan-induced rat paw edema bioassay. These compounds (2g and 2k) proved to have superior gastrointestinal safety profiles as compared to celecoxib, when tested for their ulcerogenic effects. Compounds 2g and 2k showed no inhibition against the enzymatic activity of bovine COX-2 (in vitro).  相似文献   

14.
Yan XH  Di YT  Fang X  Yang SY  He HP  Li SL  Lu Y  Hao XJ 《Phytochemistry》2011,72(6):508-513
Eight limonoids (1-8) including three A, B and D-seco-16-nor-type ones, 5,6-dehydrodesepoxyharperforin C2 (1), harrpernoid B (2), and its C-9S epimer, harrpernoid C (3), along with six known compounds (9-14), were isolated from fruits of Harrisonia perforata. Extensive spectroscopic analysis was used to elucidate their structures and stereochemistries. Further confirmation of structures of 1 and 2 were obtained by single-crystal X-ray diffraction. Limonoids (1-8) were evaluated for their anti-tobacco mosaic virus activity and in vitro cytotoxicity against A549 and HL60 cell lines; only compound 2 showed weak activity.  相似文献   

15.
The reduction of 2-nitro-1,3-di(pyridin-2-yl)-1,3-di(tert -butyldimethylsilyloxy)propane 1 with sodium borohydride affords 2-amino-1,3-di(pyridin-2-yl)-1,3-di(tert-butyldimethylsilyloxy)propane 2 which was subsequently reacted with salicyl aldehyde yielding rac-((2,2,3,3,9,9,10,10-octamethyl-5,7-di(pyridin-2-yl)-4,8-dioxa-3,9-disilaundecan-6-ylimino)methyl)phenol (Proligand 3 = HL(SiMe2tBu)2), with excellent yield. Reaction of 3 with vanadyl acetylacetonate followed by aerial oxidation diastereoselectively led to the octahedral coordinated vanadium(V) complex 4([VO(OMe)L(SiMe2t Bu)]). Compound 3 together with vanadyl acetylacetonate as well as with molybdenyl acetylacetonate shows catalytic activity in the sulfoxidation of (methylsulfanyl)benzene I, which was followed by NMR spectroscopy. The vanadium complex 4 was also able to catalyze the sulfoxidation but was considerably slower. All three tested catalytic systems lead to almost quantitative formation of the sulfoxide with only minor formation of the respective sulfone.  相似文献   

16.
Stilbenoids, syagrusins A-B (1-2), and a stilbenolignan, 5-hydroxyaiphanol (3), along with three known phenylpropanoids (4-6), were isolated from seeds of Syagrus romanzoffiana. Compounds 1 and 2 possess unusual 1,4,4a,9a-tetrahydrofluoren-9-one and bicyclo[3.3.0]octanedione skeletons, respectively, whereas compound 3 is a stilbenolignan belonging to a very rare structural class of plant secondary metabolites. Their structures were elucidated by spectroscopic analyses. Compounds 1-3 exhibited moderate inhibitory activity against α-glucosidase with IC50 values of 16.9 μM (1), 23.7 μM (2) and 12.8 μM (3), respectively.  相似文献   

17.
Plant genome possesses over 100 protein phosphatase (PPase) genes that are key regulators of signal transduction via phosphorylation/dephosphorylation event. Here we report a comprehensive functional analysis of protein serine/threonine, dual-specificity and tyrosine phosphatases using recombinant PPases produced by wheat cell-free protein synthesis system. Eighty-two recombinant PPases were successfully produced using Arabidopsis full-length cDNA as templates. In vitro PPase assay was performed using phosphorylated myelin basic protein as substrate. Among the AtPPases examined, 26 serine/threonine, three dual-specificity and one tyrosine PPases exhibited catalytic activity, including 20 serine/threonine and one dual-specificity PPases that showed in vitro activities for the first time. Our study demonstrates genome-wide biochemical analysis of AtPPases using wheat cell-free system, and provides new information and insights on enzyme activities.

Structured summary of protein interactions

PTP1dephosphorylatesMBP by phosphatase assay (View interaction).AtPP2CdephosphorylatesMBP by phosphatase assay (View interaction).POLTEdephosphorylatesMBP by phosphatase assay (View interaction).TOPP8dephosphorylatesMBP by phosphatase assay (View interaction).HAB1dephosphorylatesMBP by phosphatase assay (View interaction).ABI2dephosphorylatesMBP by phosphatase assay (View interaction).At1g34750dephosphorylatesMBP by phosphatase assay (View interaction).At1g43900dephosphorylatesMBP by phosphatase assay (View interaction).At3g15260dephosphorylatesMBP by phosphatase assay (View interaction).At5g53140dephosphorylatesMBP by phosphatase assay (View interaction).At1g18030dephosphorylatesMBP by phosphatase assay (View interaction).At3g06270dephosphorylatesMBP by phosphatase assay (View interaction).At2g25070dephosphorylatesMBP by phosphatase assay (View interaction).At3g02750dephosphorylatesMBP by phosphatase assay (View interaction).At5g10740dephosphorylatesMBP by phosphatase assay (View interaction).at4g26080dephosphorylatesMBP by phosphatase assay (View interaction).At4g28400dephosphorylatesMBP by phosphatase assay (View interaction).At5g06750dephosphorylatesMBP by phosphatase assay (View interaction).At4g31860dephosphorylatesMBP by phosphatase assay (View interaction).At3g17250dephosphorylatesMBP by phosphatase assay (View interaction).At4g38520dephosphorylatesMBP by phosphatase assay (View interaction).At3g05640dephosphorylatesMBP by phosphatase assay (View interaction).At5g66080dephosphorylatesMBP by phosphatase assay (View interaction).At1g79630dephosphorylatesMBP by phosphatase assay (View interaction).At2g30170dephosphorylatesMBP by phosphatase assay (View interaction).At5g24940dephosphorylatesMBP by phosphatase assay (View interaction).  相似文献   

18.
A series of new ruthenium(II) carbonyl chloride complexes with pyridine-functionalised N-heterocyclic carbenes [Ru(Py-NHC)(CO)2Cl2], [Py-NHC = 3-methyl-1-(2-pyridyl)imidazol-2-ylidene, 1 (1a and 1b); 3-methyl-1-(2-picoyl)imidazol-2-ylidene, 2 (2a and 2b); 3-methyl-1-(2-pyridyl)benzimidazolin-2-ylidene, 3 (3b); 3-methyl-1-(2-picoyl)benzimidazolin-2-ylidene, 4 (4a and 4b); 1-methyl-4-(2-pyridyl)-1,2,4-triazoline-5-ylidene, 5 (5a and 5b)] have been prepared by transmetallation from the corresponding silver carbene complexes and characterized by NMR, IR spectroscopy and elemental analysis. In these complexes with bidentate Py-NHC ligands, one CO ligand is trans to the Py ligand. In 1a, 2a, 4a, and 5a, the NHC ligand is trans to the other CO ligand, thus leaving the two Cl ligands trans to each other. In 1b, 2b, 3b, 4b, and 5b, the NHC ligands are trans to one Cl ligand, and the two Cl ligands are cis to each other. The structures for 1b, 2b, 3b and 4b have been determined by single-crystal X-ray diffraction. These complexes are efficient catalysts in the transfer hydrogenation of acetophenone and their catalytic activities are found to be influenced by electronic effect of the N-heterocyclic carbene ligands.  相似文献   

19.
In this paper we report on the synthesis and characterization of three cobalt complexes described as [CoII(L1)2] (1), [CoII(L2)] (2), and [CoIII(L1)2]ClO4(3). These complexes contain the deprotonated forms of the [NN′O] tridentate ligand HL1 and its newly synthesized [N2N′2O2] hexadentate counterpart H2L2, namely, 2,4-diiodo-6-((pyridine-2-ylmethylamino)methyl)phenol and 6,6′-((ethane-1,2-diylbis((pyridin-2-ylmethyl) azanediyl))bis(methylene))bis(2,4-diiodophenol). Characterizations for 1-3 include electrospray ionization (ESI) spectrometry, infrared, and UV-visible spectroscopies, and elemental analyses. A detailed 1H-NMR study was conducted for 3 and X-ray structural data was obtained for 2. The viability of this series as potential agents for proteasome inhibition and cell apoptotic induction involving PC-3 cancer cells is presented comparing the behavior of the untethered [NN′O]2 six-coordinate 1 and 3 and the tethered counterpart 2 with a 1:1 metal-to-ligand ratio. It is observed that the tethering in 2 decreases inhibition activity. When 1 and 3 are compared, the most inert, but redox-active, cobalt(III) species shows the highest chymotrypsin-like activity inhibition on purified proteasome and PC-3 cancer cells. A hypothesis based on the role of oxidation states for proteasome inhibition is offered.  相似文献   

20.
A series of novel 3,4-dihydropyrimidin-2(1H)-one urea derivatives of biological interest were prepared by sequential Bigineli’s reaction, reduction followed by reaction of resulting amines with different arylisocynates. All the synthesized (1-23) compounds were screened against the pro-inflammatory cytokines (TNF-α and IL-6) and antimicrobial activity (antibacterial and antifungal). Biological activity evaluation study reveled that among all the compounds screened, compounds 12 and 17 found to have promising anti-inflammatory activity (68-62% TNF-α and 92-86% IL-6 inhibitory activity at 10 μM). Interestingly compounds 3, 4, 5, 6, 15, 22 and 23 revealed promising antimicrobial activity at MIC of 10-30 μg/mL against selected pathogenic bacteria and fungi.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号