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921.
The immobilization of copper complexes by covalent anchoring of the ligand on the surface of mesoporous MCM‐41 has been described. Bis[2‐(phenylthio)benzylidene]‐1,2‐ethylenediamine as a new N2S2 donor salen‐type ligand was covalently anchored onto nanopores of MCM‐41 coordinated with copper (I) halide. The organic–inorganic hybrid material was achieved readily using 3‐mercaptopropyltrimethoxysilane as a reactive surface modifier. 2‐Nitrobenzaldehyde was reacted smoothly with the thiol moieties in order to form functionalized nanoporous silica with carbaldehyde groups. The resulting supported organic moieties were converted to thiosalen ligand and coordinated with CuX (X = CN, Cl, Br, I). Characterization of the heterogeneous catalyst by X‐ray diffraction, N2 sorption, FT‐IR, diffuse reflectance UV‐visible and TGA techniques indicated successful grafting of the copper complex inside the nano‐channels of MCM‐41. The heterogenized catalyst was evaluated by the Mannich condensation reaction of aldehydes, amines and alkynes. In this reaction, the corresponding propargylamines were obtained as single products in good to excellent yields. Factors such as reaction temperature, solvent, catalyst loading, leaching and reusability of the catalyst also were discussed. The use of MCM‐41 as support permits an easier separation and recycles with only a marginal decrease in reactivity. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
922.
Javad Safaei-Ghomi Raheleh Teymuri Hossein Shahbazi-Alavi Abolfazl Ziarati 《中国化学快报》2013,24(10):921-925
A highly efficient and general method for the synthesis of polyfunctionalized 4H-pyrans is established through a one-pot multicomponent cyclocondensation of aromatic aldehydes with CH acids, malononitrile and ethyl acetoacetate using nano silica supported tin (Ⅱ) chloride as a catalyst. In this method SnCl2/nano SiO2 was used as green and reusable catalyst. Excellent yields, short reaction times, simple workup, and inexpensiveness and commercially availability of the catalyst are the advantages of this method. 相似文献
923.
Gholamian Forouzan Chaloosi Marzieh Husain Syed Wagif Dehghani Hossein 《平面色谱法杂志一现代薄层色谱法》2001,14(4):296-299
JPC – Journal of Planar Chromatography – Modern TLC - High-performance thin-layer chromatography (HPTLC) has been used for separation and quantitation of components of high explosives... 相似文献
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926.
Amir Hossein Gandomi Amir Hossein Alavi 《Communications in Nonlinear Science & Numerical Simulation》2012,17(12):4831-4845
In this paper, a novel biologically-inspired algorithm, namely krill herd (KH) is proposed for solving optimization tasks. The KH algorithm is based on the simulation of the herding behavior of krill individuals. The minimum distances of each individual krill from food and from highest density of the herd are considered as the objective function for the krill movement. The time-dependent position of the krill individuals is formulated by three main factors: (i) movement induced by the presence of other individuals (ii) foraging activity, and (iii) random diffusion. For more precise modeling of the krill behavior, two adaptive genetic operators are added to the algorithm. The proposed method is verified using several benchmark problems commonly used in the area of optimization. Further, the KH algorithm is compared with eight well-known methods in the literature. The KH algorithm is capable of efficiently solving a wide range of benchmark optimization problems and outperforms the exciting algorithms. 相似文献
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928.
Herein we report chemical and electrochemical formation of poly(3‐methoxyethoxythiophene) and its copolymers with aniline, thiophene and pyrrole which give highly conducting polymeric materials. These are soluble in common organic solvents in the conducting state. The response mechanism of these compounds, to a selection of gases and vapours, was investigated using two techniques: measurement of conductance and mass changes using a four probe method and X‐ray fluorescence (XRF) device, respectively. Prepared films were exposed to hydrogen halides, hydrogen cyanide, halogens, monochloroacetic acid (MCAA), 1‐3‐5 trichloromethylbenzene (TCMB), methylbenzyl bromide (MBB), bromoacetone (BA) and cyanogen bromide (CB). These gas sensors may have advantages compared to other sensors in their ability to operate at room temperature, low concentration, stability in air, sufficient diffusion and their selectivity. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
929.
Firouz Matloubi Moghaddam Hossein Ismaili Ghasem Rezanejade Bardajee 《Heteroatom Chemistry》2006,17(2):136-141
A simple, fast and efficient benign procedure has been developed for one‐pot synthesis of 2‐substituted benzothiazoles in the presence of zirconium(IV) oxide chloride octahydrate (ZrOCl2·8H2O) and anhydrous copper(II) sulfate. The reaction of 2‐aminothiophenol with aldehydes and anhydrides was carried out efficiently in solvent‐free conditions with or without microwave irradiation, and adducts were produced in good to excellent yields. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:136–141, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20191 相似文献
930.
Negin Dehghan Hossein Nasr-Isfahani Afshin Sarvary Mohammad Bakherad 《Journal of heterocyclic chemistry》2021,58(1):350-356
A double four component Azido-Ugi reaction of isocyanide, TMSN3, aldehyde, and 4,4′-sulfonyldianiline with two amine functional groups in MeOH at 65°C has been described. The synthesis of pharmacologically and structurally interesting compounds with two 1,5-disubstituted tetrazole rings via a reaction from available and inexpensive reagents under a convenient process and mild reaction conditions has been reported. Modifications in the structure of the reaction product could be followed by varying the aldehyde or isocyanide component. The products are new and were well described by Mass, 1H NMR, and 13C NMR spectral studies. 相似文献