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1.
韩永滨  李嫕  杨国强 《化学进展》2004,16(2):284-290
固相合成方法具有传统液相反应无可比拟的优越性,已被越来越多的化学家认可.反应物与高分子支持体的连接则是固相合成中的重要环节,连接体在其中扮演着重要的角色.近20多年来发展起来的有机硅连接体基本满足了理想连接体的要求,具有广阔的应用发展前景.本文从直接法和间接法两方面综述了26年来具有代表性的多种有机硅连接体的设计、制备及其在固相有机合成中的应用.  相似文献   

2.
己二酸是工业上具有重要应用的二元羧酸,其合成方法的研究受到了广泛的关注.其传统的合成方法对环境造成了极大的破坏.利用含钨化合物作为催化剂催化合成己二酸是一种绿色环保的新方法,引起了人们的重视.作者介绍了近年来含钨化合物催化合成己二酸的研究进展,分析比较了不同催化剂体系的研究情况,展望了今后己二酸合成的发展前景.  相似文献   

3.
The condensation of aniline and cyclohexanol (cyclohexanone) yielding intermediates and the subsequent dehydrogenation of these intermediates into diphenylamine have been studied. The mechanism of diphenylamine synthesis is substantiated. The kinetics of diphenylamine synthesis from aniline and cyclohexanol over a NiSnMg catalyst has been studied. A kinetic model in terms of the conversion of strongly chemisorbed species has been developed. The rate constants of diphenylamine synthesis at 260–300°C have been determined, which are consistent with the observed regularities. The kinetic model can be used in the determination of optimal synthetic conditions and in the design of a reactor for diphenylamine synthesis from aniline and cyclohexanol. Conditions have been found under which diphenylamine synthesis occurs at a high rate of up to 1 kg/(1h), with high selectivity, and with a high yield of up to 95%.  相似文献   

4.
The new developments in the field of gas phase synthesis, synthesis from the condensed phases and solid‐state synthesis allowing for the fabrication of new ceramic materials for diverse technical applications have been reviewed. The Flame Spray Pyrolysis, aqueous and non‐aqueous sol‐gel techniques, hydro‐ and solvothermal methods, polymer pyrolysis route and high pressure techniques have been considered as synthesis methods with great technical potential.  相似文献   

5.
蔗糖酯的酶催化区域选择性合成   总被引:9,自引:0,他引:9  
酶可以区域选择性地合成蔗糖酯,枯草杆菌等蛋白酶被用来区域选择性合成 1'-O-蔗糖酯,且通常不接受长链(大于C_(12))脂肪酸作为酰基授体,而脂肪酶可 催化宽范围的脂肪酸,除了脂肪酶和蛋白酶外,研究发现抗体酶也能区域和立体选 择地酰化蔗糖。蔗糖二酯、线型蔗糖酯都可以通过酶催化区域选择性地合成。酶催 化合成蔗糖酯通常在二甲基甲酰胺、二甲基亚砜和吡啶等有毒溶剂中进行。近几年 来,无溶剂条件下酶催化合成蔗糖酯,以及用叔丁醇等毒性较小的溶剂代替毒性较 大的溶剂的研究,也越来越受重视。  相似文献   

6.
FeCo alloy nanoparticles encapsulated in the carbon matrix of metal–carbon nanocomposites have been manufactured under IR heating. The size of FeCo nanoparticles have been found to be tailored by varying synthesis temperature and metal concentration. The saturation magnetization has been shown to increase as the synthesis temperature or metal concentration rises, with an attendant decrease in coercive force. The electromagnetic properties of FeCo/C nanocomposites have been studied. Complex magnetic permittivity measurements have shown that variation of the synthesis temperature or metal concentration can appreciably increase magnetic loss, which leads to a shift of the band of minimum electromagnetic reflectivity in the frequency range 3–12 GHz.  相似文献   

7.
Studies towards the synthesis of epothilone A via organoboranes have been described. A modified procedure for the large-scale preparation of B-gamma,gamma-dimethylallyldiisopinocampheylborane from prenyl alcohol has been developed. This reagent, upon reaction with various aldehydes, provides the corresponding alpha,alpha-dimethylhomoallylic alcohols in high enantioselectivities. The application of this reagent for the synthesis of the C1-C6 subunit of epothilone has been demonstrated. Alternatively, inter- and intramolecular asymmetric reduction protocols have also been utilized for the synthesis of the C1-C6 subunit of epothilone A. The synthesis of the C7-C21 fragment of epothilone A involving asymmetric alkoxyallyl- and crotylboration using alpha-pinene-derived reagents has also been described.  相似文献   

8.
苗晓  王来来 《分子催化》2014,(3):282-293
正手性过渡金属配合物催化的不对称氢化是合成手性药物、农药和精细化工中间体的重要方法.到目前为止,已经有一些过渡金属/配体配合物催化的不对称氢化反应得到工业化应用,典型的实例如孟山都公司采用手性双齿膦配体DIPAMP生产L  相似文献   

9.
Palladium-catalyzed tandem multifunctional reactions leading to the synthesis of substituted biaryl molecules have been developed including tandem Heck-direct arylation and tandem-sequential Heck-direct arylation-hydrogenation. These reactions occur in good yield and have been employed in the synthesis of a cytotoxic biaryl compound.  相似文献   

10.
制备了无机高分子复合絮凝剂聚硅酸硫酸铁(PFSS)和助凝剂壳聚糖(CTS),考察了影响合成及絮凝剂应用的因素,探讨了其组成、投加量以及pH值对城市废水絮凝效果的影响,通过对模拟废水和城市废水絮凝试验,得出最佳的合成和应用条件:n(Fe)∶n(Si)=1∶1,PFSS的碱化度为1.5,聚合硫酸铁(PFS)的pH=2,聚硅酸(PS)的活化时间为1.5 h;n(PFSS)∶n(CTS)=5∶1,投加量为(20+4) mg/L,pH值的范围为6~9,沉降时间为15 min。 复合絮凝剂(PFSS-CTS)在最佳条件下浊度、色度、COD的去除率分别达到95.04%、91.26%和83.45%。  相似文献   

11.
手性离子液体在有机合成中的应用   总被引:1,自引:0,他引:1  
近年来,手性离子液体的应用研究取得了重要进展,新的手性离子液体的不断涌现促使人们对其应用研究的兴趣不断提高.本文综述了手性离子液体在有机合成中应用研究的新进展.  相似文献   

12.
Gold nanoparticles have been employed in biomedicine since the last decade because of their unique optical, electrical and photothermal properties. Present review discusses the microbial synthesis, properties and biomedical applications of gold nanoparticles. Different microbial synthesis strategies used so far for obtaining better yield and stability have been described. It also includes different methods used for the characterization and analysis of gold nanoparticles, viz. UV–visible spectroscopy, Fourier transform infrared spectroscopy, X ray diffraction spectroscopy, scanning electron microscopy, ransmission electron microscopy, atomic force microscopy, electron dispersive X ray, X ray photoelectron spectroscopy and cyclic voltametry. The different mechanisms involved in microbial synthesis of gold nanoparticles have been discussed. The information related to applications of microbially synthesized gold nanoparticles and patents on microbial synthesis of gold nanoparticles has been summarized.  相似文献   

13.
Liang J  Peng Q  Wang X  Zheng X  Wang R  Qiu X  Nan C  Li Y 《Inorganic chemistry》2005,44(25):9405-9415
A general synthesis route to a family of single-crystal chromate nanorods/nanobelts has been established. The effects of pH and surfactant on phase and morphology of these microcrystalline materials have been investigated. The physical properties of the as-synthesized chromate nanocrystals such as dielectric, electrochemical, UV-vis absorbance, and photoluminescent properties have also been studied. The present general synthesis of various low-dimensional chromate nanomaterials provides useful information on the possible synthesis of other microcrystalline transition metal oxysalts.  相似文献   

14.
A selective method for the synthesis of 1,6-substituted glycolurils has been developed. The glycolurils have been used for the synthesis of methylene-bridged glycoluril dimers bearing hydrogen atoms on their convex face. Depending on the side walls of the dimers, different modes of self-assembly in the solid state have been described using X-ray crystallography.  相似文献   

15.
讨论了固定床反应器模型的建立过程和工作步骤,确定固定床F-T合成反应器用非均相二维模型来描述。总结评价了固定床反应器模型方程的数值计算方法,确定了固定床F-T合成反应器模型方程的数值计算方法。  相似文献   

16.
《Tetrahedron》2013,69(42):8936-8942
The straightforward synthesis of a highly biologically active 3-piperazine-bisbenzoxaborole and its fluorine analog has been described. The obtained bisbenzoxaboroles have been used in the synthesis of their phenylboronic acids analogs. One diboronic acid has been also isolated as hydrochloride salt as well as its methyl monoester. All the described compounds display unique molecular architectures, which have been determined by X-ray measurements.  相似文献   

17.
Current advancements in green synthesis of materials especially nanoparticles have led to conservation of natural and non-renewable resources along with reduction in environmental pollution. Development of cost-effective, simple and eco-friendly routes for the synthesis of nanoparticles is very important. All over the world, a wide variety of biogenic sources have been put to trial as a source of green agents to facilitate synthesis process. In addition to this, environmentally benign solvents are also being used these days in order to promote green synthesis. In this review, an attempt has been made to familiarise the readers with the different green routes for the synthesis of nanoparticles.  相似文献   

18.
At present anthracycline antibiotics have proven to be the most exciting agents in cancer chemotherapy. Both adriamycin and daunomycin are proven to be effective against a variety of human tumour cells, despite their cardiotoxicity. However, some synthetic analogues, such as 4-demethoxydaunomycin, are shown to be better therapeutic ratios compared to adriamycin or daunomycin. Various approaches have been successfully made for the total synthesis of (±) 4-demethoxydaunomycinone, the aglycone of (±) 4=demethoxydaunomycin, starting from benzoquinone, napthalene or anthraquinone precursors. Finally an elegant approach for the stereoconvergent synthesis of (+) 4-demethoxydaunomycinone has been worked out. New methods involving both Diels-Alder and Friedal-Crafts acylation, have been developed for the total synthesis of daunomycinone and 11-deoxydaunomycinone. The synthesis of L-daunosamine, the amino sugar unit present in the antitumor anthracyclines has been successfully elaborated starting either from D-glucose or D-glucosamine.  相似文献   

19.
Since Faraday first described gold sol synthesis, synthetic routes to nanoparticles, as well as their applications, have experienced a huge growth. Variations in synthesis conditions such as pH, temperature, reduction, and the stabilizing agent used will determine the morphology, size, monodispersity, and stability of nanoparticles obtained, allowing for modulation of their physical and chemical properties. Although many studies have been made about the synthesis and characterization of individual nanosystems of interest, to our knowledge the common, general traits that all those synthesis share have not been previously compiled. In this review, we aim to offer a global vision of some of the most relevant synthetic procedures reported up to date, with a special focus on nonfunctionalized gold nanoparticle synthetic routes in aqueous media, and to display a broad overview of the influence that synthesis conditions have on the shape, stability, and reactivity of nanoparticle systems.  相似文献   

20.
离子液体在无机纳米材料合成上的应用   总被引:23,自引:0,他引:23  
室温离子液体作为一种新型的绿色环保溶剂,在无机纳米材料合成中的应用引起越来越多研究者的注意。目前,已经利用室温离子液体合成出了纳米多孔材料、纳米粒子和中空球、一维纳米材料等。与传统的溶剂相比,离子液体在合成过程中体现出了很多优势,且合成的产物也不同,为无机纳米材料的合成开辟了一条新途径。本文就近年来国内外相关研究进展,对离子液体在无机纳米材料合成中的应用进行综述。  相似文献   

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