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81.
Borghei Sina Dehghanian Changiz Yaghoubi Rouhollah Yari Saeed 《Research on Chemical Intermediates》2016,42(5):4551-4568
Research on Chemical Intermediates - A new imidazoline derivative, {[(benzimidazol-2-ylmethyl)imino]bis(methylene)} bis(phosphonicacid), named as BMIBMBPA, was synthesized as an environmentally... 相似文献
82.
Oxidative amidation of aromatic aldehydes with amine hydrochloride salts catalyzed by silica‐coated magnetic carbon nanotubes (MagCNTs@SiO2)‐immobilized imine–Cu(I) 下载免费PDF全文
Mesoporous silica‐coated magnetic carbon nanotubes were prepared; their surface functionalization, followed by reaction with CuI, were carried out to develop a Cu‐grafted functionalized mesoporous material. This system is able to catalyze oxidative amidation of aromatic aldehydes with amine hydrochloride salts, generating amide derivatives in moderate to good yields. Magnetic properties of this catalyst led to easy separation as well as providing significant recyclability. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
83.
P(AA)‐Ag heterogeneous catalyst system comprised of Ag nanoparticles embedded within hydrogel matrices has been described for the selective aerobic oxidation of alcohols and reduction of nitro phenols in water. P(AA)‐Ag nanocomposite was characterized by Fourier transform infrared (FT‐IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), X‐Ray photoelectron spectroscopy (XPS) and inductively coupled plasma atomic emission spectrometer (ICP). Catalytic activity of p(AA)‐Ag catalyst was investigated in the aerobic oxidation of primary alcohols and reduction of nitro compounds by emphasizing the effect of different parameters such as temperature, catalyst amount, substituent effect, etc. The catalyst was easily recovered from the reaction medium and it could be re‐used for other three runs without significant loss of activity. 相似文献
84.
Phosphated tungstate as a new, reusable and efficient solid phosphoric acid catalyst was synthesized and used to promote the reaction of diaminoglyoxime with various aromatic aldehydes. The prepared phosphated tungstate was characterized using various techniques including X‐ray diffraction, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, Fourier transform infrared spectroscopy and thermal analysis. A wide variety of heterocyclic nitrones were obtained under mild reaction conditions and in high yields by using the prepared catalyst. 相似文献
85.
Malek Taher Maghsoodlou Norollah Hazeri Sayyed Mostafa Habibi Khorassani Reza Heydari Mahmoud Nassiri Ghasem Marandi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4):865-877
Stable crystalline phosphorus ylides were obtained in excellent yields from the 1:1:1 addition reaction between triphenylphosphine and dialkyl acetylenedicarboxylates in the presence of strong NH-acids, such as benzotriazole, 5-methylbenzotriazole, 5-chlorobenzotriazole, pyrrole, 2-acetylpyrrole, pyrrole-2-carboxaldehyde, 4-nitro-acetanilide, 4-methoxyacetanilide, 4-bromoacetanilide, 4-methylacetanilide, 2-methyl-acetanilide, and 2,6-dimethylacetanilide. These stable ylides exist in a solution as a mixture of two geometrical isomers as a result of the restricted rotation around the carbon–carbon partial double bond resulting from the conjugation of the ylide moiety with the adjacent carbonyl group. 相似文献
86.
In this paper, we consider a charged rotating black hole in three dimensions with a scalar charge, and discuss thermodynamics quantities. We find effects of the black hole parameters on the temperature, entropy, free energy, total energy and specific heat. We also investigate the stability of the black hole and study phase transition. We consider the first law of thermodynamics and find that satisfied. 相似文献
87.
Let \(R\) be a commutative ring and \(M\) be an \(R\) -module. In this paper, we introduce the \(M\) -principal graph of \(R\) , denoted by \(M-PG(R)\) . It is the graph whose vertex set is \(R\backslash \{0\}\) , and two distinct vertices \(x\) and \(y\) are adjacent if and only if \(xM=yM\) . In the special case that \(M=R, M-PG(R)\) is denoted by \(PG(R)\) . The basic properties and possible structures of these two graphs are studied. Also, some relations between \(PG(R)\) and \(M-PG(R)\) are established. 相似文献
88.
Mojtaba Taslimi Tehrani Hoshang Heydari 《International Journal of Theoretical Physics》2012,51(11):3614-3626
Based on spherically symmetric reduction of loop quantum gravity, quantization of the portion interior to the horizon of a Reissner-Nordström black hole is studied. Classical phase space variables of all regions of such a black hole are calculated for the physical case M 2>Q 2. This calculation suggests a candidate for a classically unbounded function of which all divergent components of the curvature scalar are composed. The corresponding quantum operator is constructed and is shown explicitly to possess a bounded operator. Comparison of the obtained result with the one for the Schwarzschild case shows that the upper bound of the curvature operator of a charged black hole reduces to that of Schwarzschild at the limit Q→0. This local avoidance of singularity together with non-singular evolution equation indicates the role quantum geometry can play in treating classical singularity of such black holes. 相似文献
89.
In this paper, a new and effective direct method to determine the numerical solution of pantograph equation, pantograph equation with neutral term and Multiple-delay Volterra integral equation with large domain is proposed. The pantograph equation is a delay differential equation which arises in quite different fields of pure and applied mathematics, such as number theory, dynamical systems, probability, mechanics and electrodynamics. The method consists of expanding the required approximate solution as the elements of Chebyshev cardinal functions. The operational matrices for the integration, product and delay of the Chebyshev cardinal functions are presented. A general procedure for forming these matrices is given. These matrices play an important role in modelling of problems. By using these operational matrices together, a pantograph equation can be transformed to a system of algebraic equations. An efficient error estimation for the Chebyshev cardinal method is also introduced. Some examples are given to demonstrate the validity and applicability of the method and a comparison is made with existing results. 相似文献
90.
Reza Heydari Nourallah Hazeri Malek Taher Maghsoodlou Sayyed Mostafa Habibi Khorassani Ghasem Marandi Nariman Maleki 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2135-2141
Hydrazine sulfonamide derivatives undergo a smooth reaction with dialkyl acetylenedicarboxylates in the presence of triphenylphosphine in varieties of solvent for generation of phosphorus ylides in a chemoselective manner. 相似文献