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1.
程文旦  黄锦顺 《结构化学》1993,12(6):445-448
比较了含有配位不饱和过渡金属原子簇合物Mo_2S_4(dtp)_2,(Ⅰ)和Mo_3S_4(dtp)_4·Py,(Ⅱ)的紫外—可见电子吸收光谱实验数据和半经验的量子化学方法INDO计算得到的电子跃迁能,讨论了(d-p)π型共轭作用对其电子吸收光谱位移的影响。结果表明,过渡金属簇合物中电子吸收光谱位移,与有机共轭体系有着类似的变化规律,即随着共轭π键数目增加,π-π电子跃迁的吸收光谱红移。  相似文献   

2.
万博  赵庆鲁  王来来 《催化学报》2010,31(5):514-517
 以联萘酚和大位阻的金刚烷酰氯为原料, 经两步合成了系列新型手性单齿亚磷酸酯配体, 并应用于铜催化的二乙基锌对环烯酮的不对称 1,4-共轭加成反应. 结果表明, 产物收率和对映选择性最高分别为 95% 和 61%. 配体 (S)-(2-(adamantane- 1-carboxylic acid)-1,1’-binapthalen-2’-yl)-((S)-1,1’-binaphthalen-2,2’-yl)phosphite [(S,S)-3a]的两个 (S)-联萘酚构型是匹配的组合, 产物的绝对构型主要由配体中 2,2’-二氧膦-1,1’-联萘酚的构型控制.  相似文献   

3.
A straightforward approach for the construction of the new class of conjugated pyrans based on enamination of 2-methyl-4-pyrones with DMF-DMA was developed. 2-(2-(Dimethylamino)vinyl)-4-pyrones are highly reactive substrates that undergo 1,6-conjugate addition/elimination or 1,3-dipolar cycloaddition/elimination followed by substitution of the dimethylamino group without ring opening. This strategy includes selective transformations leading to conjugated and isoxazolyl-substituted 4-pyrone structures. The photophysical properties of the prepared 4-pyrones were determined in view of further design of novel merocyanine fluorophores. A solvatochromism was found for enamino-substituted 4-pyrones accompanied by a strong increase in fluorescence intensity in alcohols. The prepared conjugated structures demonstrated valuable photophysical properties, such as a large Stokes shift (up to 204 nm) and a good quantum yield (up to 28%).  相似文献   

4.
谢素雯  胡孝贵 《化学通报》2007,70(3):237-239
(E)-1-氯-6,6-二甲基-2-庚烯-4-炔是合成盐酸特比萘芬的关键中间体,N-氯代二异丙胺/三苯基膦与6,6-二甲基-1-庚烯-4-炔-3-醇反应,可以立体选择性地得到反式的该化合物,其反式/顺式异构体的比例达9/1,为特比萘芬提供了可工业放大生产的立体选择性合成方法。  相似文献   

5.
王欢  杨定乔  莫海洪 《有机化学》2007,27(7):806-818
铑催化不对称1,4-共轭加成反应是一种非常有效的碳-碳键形成方法. 本文综述了近年来铑催化不对称1,4-共轭加成反应的研究进展, 包括α,β-不饱和酮、酯、酰胺、醛和砜等与某些亲核试剂的1,4-共轭加成反应.  相似文献   

6.
Two Wang resin-supported (1R,2R)-(+)-1,2-DPEN(DPEN=diphenylethylenediamine) catalysts were synthesized from cyanuric chloride and trimesoyl chloride, respectively. These two catalysts were characterized by FTIR, TGA and elemental analysis. The results demonstrated that (1R,2R)-(+)-1,2-DPEN was successfully bonded to the surface of Wang resin through the amido linkage. Subsequently, the asymmetric Michael addition of acetone to β-nitrostyrene was employed to evaluate their catalytic performance. It was found that the catalyst generated from trimesoyl chloride exhibited much better catalytic behavior than our previously reported catalyst, likely attributed to the multiple hydrogen-bond interaction between β-nitrostyrene and amide group, which made the catalytic transition intermediates more stable. Under the optimal conditions, 76.1% β-nitrostyrene conversion and 93.8% enantioselectivity were obtained. Finally, the generality of this catalyst was examined with Michael additions of acetone to β-nitroolefins and excellent enantioselectivities(91.9% to 99.9%) were achieved.  相似文献   

7.
Unsymmetrical Triorganobismuthanes Containing β-Functionalized Alkylsubstituents Sodium diorganobismuthide, was treated with strained ring systems such as propyleneoxide, styreneoxide, ethylene-sulfide or propyleneimine to produce unsymmetrical triorganobismuthanes R2BiCH2CH(R′)XH (R = Me, Et, Ph, pTol; R′ = H, Me, Ph; X = O, S, NH) in good yields.  相似文献   

8.
研究了一条新的路线用于(S)-6-苄氧基-5-羟基-3-氧代-己酸叔丁酯的合成. 以廉价、易得的R-环氧氯丙烷为起始原料, 经过几步比较温和的反应得到目标化合物. 在此基础上, 通过对催化剂三氟化硼乙醚用量的考察以及两条反应路线优缺点的比较, 找到了一条适合大规模制备的工艺路线. 该路线具有收率高、原料易得、反应条件温和、产物容易分离、提纯等特点.  相似文献   

9.
Optically active (4R,8RS)-dimethyldecanal, an analog of the aggregation pheromone of the flour beetles Tribolium confusum and T. Castaneum, and (4R)-methylnonan-1-ol, the sex pheromone of the yellow mealworm Tenebrio molitor L., are synthesized using ozonolytic transformation of (6R,10)-dimethyl-9-undecen-2-one to (6R)-methyl-9-hydroxynonan-2-one in the key step. The starting compound is available as enantiomerically enriched (ee ~50%) (S)-(+)-3,7-dimethyl-1,6-octadiene.  相似文献   

10.
A series of three new ruthenium(III) bipyridine complexes, [RuCl3(bipy)L] (L = C6H5CHO (Ru1), 4‐CH3OC6H4CHO (Ru2) and 4‐NO2C6H4CHO (Ru3); bipy = 2,2′‐bipyridine), have been synthesized and characterized using microanalysis, magnetic, spectroscopic (IR, UV–visible, electron spin resonance) and cyclic voltammetric techniques. All the ruthenium(III) complexes were found to be stable, paramagnetic and octahedrally coordinated. Electron spin resonance spectra showed an axial symmetry and indicated a tetragonal distortion for the octahedral complexes. All complexes were tested for their cytotoxicities against Ehrlich ascites carcinoma (EAC), superoxide dismutase‐like activities and cytoprotective effects of normal human red blood cells against photo‐irradiation. All the compounds were found to be cytotoxic with half maximal inhibitory concentration (IC50) against EAC at concentrations of 70, 90 and 76 µg for Ru1, Ru2 and Ru3, respectively. Moreover, mean levels of DNA and RNA were significantly elevated in liver tissues of tumorized animals and significantly reduced after treatment of tumorized mice with the complexes. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

11.
李涛  黄贤贵  林静容  金荣华  田伟生 《化学学报》2007,65(12):1165-1171
(2R,6R)-2,6,10-三甲基十一醇(1)是维生素E、维生素K和植醇的基本结构单元. 利用从甾体皂甙元氧化降解产生的工业废弃物中所获得的手性化合物(R)-5-甲基-δ-戊酸内酯(6), 先将其转化成为化学性质稳定的(4R)-甲基-5-甲氧甲氧基戊酸甲酯(7), 再经十二步反应, 以14.1%的总收率合成得到了目标化合物(2R,6R)-2,6,10-三甲基十一醇(1).  相似文献   

12.
( )-生物素,又称维生素H或辅酶R,化学名(3aS,4S,6aR)-六氢-2-氧-噻吩并[3,4-d]咪唑-4-戊酸,属于水溶性B族维生素,是整个生物界所必须的。生物素在维持动物正常发育,繁殖及保持皮肤、羽毛和骨骼健康中发挥重要作用。自1949年瑞士Roche公司首次开发化学全合成d-生物素后,经过几十  相似文献   

13.
An active and reusable heterogeneous Rh(I) organometal catalyst (Rh(I)-PMO-3D) was synthesized by template-directed co-condensation of Rh[PPh2(CH2)2Si(OCH2CH3)3]3Cl and (CH3CH2O)3SiPhSi(OCH2CH3)3. This catalyst displayed bicontinuous cubic Ia3d mesostructure channel, which ensured the high dispersion of Rh(I) active sites and the convenient diffusion of reactant molecules into the pore channels. Meanwhile, the Ph-functionalization could enhance the surface hydrophobicity, which promoted the adsorption of organic reactant molecules on the catalyst, especially in aqueous medium. During water-medium 1,4-conjugate addition reactions, Rh(I)-PMO-3D catalyst exhibits higher catalytic activity than the corresponding homogeneous Rh(I) catalyst and could be used repetitively for more than five times, showing a good potential in industrial applications.  相似文献   

14.
Four new curcuminoid analogues, 1,7‐bis(4‐hydroxyphenyl)‐1,6‐heptadiene‐3,5‐dione, 1a ; 1,7‐di(2‐furyl)‐1,6‐heptadiene‐3,5‐dione, 1b ; 1,7‐di(2‐naphthyl)‐1,6‐heptadiene‐3,5‐dione, 1c ; 1,7‐bis(2‐chlorophenyl)‐1,6‐heptadiene‐3,5‐dione, 1d ; and their copper(II) complexes of ML2 stoichiometry were synthesized and characterized by UV, IR, 1H NMR, ESR and mass spectral data. The compounds were investigated for their possible cytotoxic and antitumour activities. It was found that copper chelates are remarkably active compared with free curcuminoid analogues. All the compounds were found to be cytotoxic towards Ehrlich ascites carcinoma cells and cultured L929 (lung fibroblast cells). In the case of culture studies, concentrations needed for 50% cell death were around 5 µg/ml for copper complexes and 10 µg/ml for curcuminoid analogues. Copper complex of 1a with hydroxyl group in the phenyl ring was found to be most active towards L929cells (1 µg/ml produced 43.3 ± 1.3% cell death). Compound 1b , which possesses a furyl ring system, was found to show least activity towards increase in life span of tumour‐bearing mice (increase in life span 39.31%). Copper chelates of all curcuminoid analogues showed a significant reduction (p < 0.001) of solid tumour volume in mice. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

15.
Three new complexes, [Cu(barb)2(aepip)] · 0.5H2O (1), [Cu(barb)2(aepyrd)] (2), and [Cu(barb)2(aemrph)] (3), have been synthesized by reaction of 5,5-diethlybarbiturate anion (barb) with copper(II) in the presence of (2-aminoethyl)piperidine (aepip), -pyrrolidine (aepyrd), and -morpholine (aemrph). All complexes were characterized by elemental analysis, spectroscopic (IR and UV/Vis), thermal (DTA-TGA), and magnetic susceptibility measurements. X-ray single crystal diffraction shows that 1 and 2 are discrete mononuclear species, in which copper(II) is coordinated by two bidentate barb ligands and a chelating aepip or aepyrd, forming a square-pyramidal coordination geometry. Complexes 1 and 2 show unequal coordination of barb, one N-coordinate, and one bidentate. Complex 3 is also mononuclear, but copper(II) is square-planar with two N-coordinated barb and one bidentate aemorph. Molecules of 13 are bridged by strong hydrogen bonds to generate 1-D or 2-D supramolecular networks. Spectral and thermal data for 13 are in agreement with crystal structures.  相似文献   

16.
In the context of our SAR study concerning 6BrCaQ analogues as C-terminal Hsp90 inhibitors, we designed and synthesized a novel series of 3-(heteroaryl)quinolin-2(1H), of types 3, 4, and 5, as a novel class of analogues. A Pd-catalyzed Liebeskind–Srogl cross-coupling was developed as a convenient approach for easy access to complex purine architectures. This series of analogues showed a promising biological effect against MDA-MB231 and PC-3 cancer cell lines. This study led to the identification of the best compounds, 3b (IC50 = 28 µM) and 4e, which induce a significant decrease of CDK-1 client protein and stabilize the levels of Hsp90 and Hsp70 without triggering the HSR response.  相似文献   

17.
目前,不对称合成光学活性化合物取得了较大进展,不对称合成α-氨基酸、β-氨基醇、α-取代苄胺的报道很多。但是,不对称合成生物碱类物质——α-取代氨甲基吡啶类化合物还未见文献报道,而此类化合物有潜在的应用前景。为此,我们以( )-樟脑为手性试剂  相似文献   

18.
2-(2-aminobenzoyl)-N-ethylhydrazine-1-carbothioamide (H3L) and its Cu (II), Co (II), Ni (II) and Zn (II) complexes have been synthesized. The structures of the isolated compounds were suggested based on elemental analyses, spectral analyses (FTIR, 1H and 13CNMR, MS, ESR and UV–Visible) and magnetic moments measurements. The free ligand exists in the keto-thione form, while in the metal complexes; it exists in the enol form and coordinates as mononegative bidentate via deprotonated enolic oxygen and N2H nitrogen. Both Co (II) and Ni (II) complexes have an octahedral, while Cu (II) complex has a square planar geometry. The compounds have direct electronic transitions with optical band gap (Eg) values in the range 3.14–3.40 eV. The ligand and its complexes were optimized using DFT/B3LYP methodology. The ligand optimization results supported the involvement of the carbonyl oxygen, thione sulfur and N2H hydrogen atoms in hydrogen bonding formation. Furthermore, the obtained structures of the ligand and its complexes were subjected to molecular docking study to predict interactions cause their cytotoxicity. Finally, the in vitro cytotoxicity activities of the ligand and its complexes were investigated against Hela and WISH cell lines where the Zn (II) complex exhibited higher activity than the other compounds against the two cell lines in accordance with molecular docking suggestion.  相似文献   

19.
The title compound (R)-N'-[2-(4-methoxy-6-chloro)-pyrimidyl]-N-[3-methyl-2-(4-chlorophenyl)butyryl]-urea has been synthesized, and its crystal structure and biological behaviors were studied. Crystallographic data: C17H18Cl2N4O3, Mr = 397.25, monoclinic, space group P21/c, a = 12.331 (2), b = 14.025(3), c = 23.085(5) (A), β = 99.607(4)°, Z = 8, V = 3936.2(13) (A)3, Dc = 1.341 g/cm3, F(000) = 1648, R = 0.0718, wR = 0.1585 and μ(MoKα) = 0.353 mm-1. The preliminary biological tests showed that the title compound has definite insecticidal and fungicidal activities.  相似文献   

20.
Abstract

An efficient, regioselective, palladium-catalyzed intramolecular cycloisomerization of dialkyl [(2-(2-ethynyl)phenyl)(2-hydroxyl)ethyl]phosphonate 6 is reported. The reactions proceed through a 6-endo-dig cyclization to afford 1H-isochromen-1-ylmethylphosphonates 7 in good to excellent yields using palladium(II) acetate as the catalyst in tetrahydrofuran at room temperature.

[Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: General Comments. Figures S1–S33.]

GRAPHICAL ABSTRACT   相似文献   

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