排序方式: 共有139条查询结果,搜索用时 140 毫秒
91.
Hadi Kargar Majid MoghadamValiollah Mirkhani Shahram TangestaninejadIraj Mohammadpoor-Baltork Mahmood Naghipour 《Polyhedron》2011,30(9):1463-1468
In the present work, the dehydrogenation of 2-substituted imidazolines with sodium periodate in the presence of tetraphenylporphyrinatomanganese(III) chloride supported on polystyrene-bound imidazole, [Mn(TPP)Cl@PSI] is reported. A wide variety of 2-imidazolines were efficiently converted to their corresponding imidazoles by the [Mn(TPP)Cl@PSI]/NaIO4 catalytic system in a 1:2 CH3CN/H2O mixture under agitation with magnetic stirring. Ultrasonic irradiation enhanced the catalytic activity of this catalyst in the oxidation of 2-imidazolines and this led to shorter reaction times and higher product yields. This catalyst could be reused several times without significant loss of its catalytic activity. 相似文献
92.
S. Abdolmanaf Taghavi Iraj Mohammadpoor-Baltork Shahram Tangestaninejad Valiollah Mirkhani Ahmad Reza Khosropour 《Comptes Rendus Chimie》2011,14(12):1095-1102
In the present work, the catalytic activity of high-valent tetraphenylporphyrinatovanadium(IV) trifluoromethanesulfonate, [VIV(TPP)(OTf)2], in the tetrahydropyranylation of alcohols and phenols with 3,4-dihydro-2H-pyran (DHP) is reported. This new electron-deficient V(IV) compound was used as a highly efficient catalyst for pyranylation of primary (aliphatic and benzylic), sterically-hindered secondary and tertiary alcohols with DHP. Tetrahydropyranylation of phenols with DHP was also performed to afford the desired THP-ethers. The chemoselectivity of this method was also investigated. The results indicated that primary alcohols are more reactive in the presence of secondary and tertiary alcohols and phenols. This catalyst was reused several times without loss of its activity. 相似文献
93.
V. Mirkhani M. Moghadam S. Tangestaninejad I. Mohammadpoor-Baltork M. Mahdavi 《Journal of the Iranian Chemical Society》2011,8(3):608-615
A highly sulfonated carbon as an efficient, recyclable, nontoxic and green solid acid catalyst was synthesized readily by simultaneous sulfonation, dehydration and carbonization of sucrose C12H22O11 in sulfuric acid and was characterized with Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric and differential thermal gravimetric analysis (TG-DTG), X-ray diffraction (XRD), carbon-hydrogen-nitrogen-sulfur analysis (CHNS), neutralization potentiometric titration and scanning electron microscopy (SEM). This new catalyst was used in one pot three-component condensation reaction of various aromatic aldehydes with ??-ketoester and urea under solvent-free conditions to afford the corresponding dihydropyrimidinones (DHPMs). This catalyst can be reused several times without loss of its activity. 相似文献
94.
I. Mohammadpoor-Baltork M. Moghadama S. Tangestaninejad V. Mirkhani Z. Eskandari H. Salavati 《Journal of the Iranian Chemical Society》2011,8(1):S17-S27
Nano-SiO2 solid acid efficiently and selectively catalyzed the cyclocondensation reaction of arylnitriles with 3-amino-1-proopanol or 1,3-diaminopropane to afford their respective 2-substituted oxazines and tetrahydropyrimidines in high yields under thermal conditions and microwave irradiation. This methodology works effectively for the selective synthesis of mono-1,3-oxazines and mono-tetrahydropyrimidnes from dinitriles. The catalyst could be recycled and reused several times without a noticeable decrease in its activity. 相似文献
95.
Rajaei P Nejadsattari T Maassoumi AA Mozaffarian V Sonboli A 《Natural product communications》2011,6(2):259-262
The essential oil was obtained from the aerial flowering parts of Tanacetum fisherae, a new record from Iran, by hydrodistillation and analyzed by GC and GC-MS. Eleven components representing 99.9% of the total oil were identified. 1,8-Cineole (79.9%) was characterized as the principal compound. The essential oil and its main component were tested against nine microbial strains. The result of the bioassays revealed that the oil possess potent antimicrobial property. This may be associated due to the presence of 1,8-cineole in the oil which tested individually and its high activity was observed. Micromorphological studies of hairs by scanning electron microscopy (SEM) exhibited the presence of abundant sessile capitate glandular and medifixed T-shaped eglandular trichomes on the leaves, flowers and achene, giving useful diagnostic characters for identification of this medicinal plant. 相似文献
96.
RuIII(OTf)SalophenCH2–NHSiO2–Fe: an efficient and magnetically recoverable catalyst for trimethylsilylation of alcohols and phenols with hexamethyldisilazane 下载免费PDF全文
Maryam Torki Shahram Tangestaninejad Valiollah Mirkhani Majid Moghadam Iraj Mohammadpoor‐Baltork 《应用有机金属化学》2014,28(4):304-309
Efficient trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) catalyzed by ruthenium(III) complex of chloromethylated Salophen supported on nanomagnetic materials is reported. First, the iron nanomagnets were silica coated, functionalized with amine and then ruthenium CM‐Salophen was successfully bonded to their surface. The catalyst, RuIII(OTf)SalophenCH2–NHSiO2–Fe, was characterized by elemental analysis, FT‐IR and UV–visible spectroscopic techniques, transmission electron microscopy and inductively coupled plasma (ICP). The RuIII(OTf)SalophenCH2–NHSiO2–Fe catalyzed trimethylsilylation of primary and secondary alcohols as well as phenols, and the corresponding TMS ethers were obtained in high yields and short reaction times at room temperature. This new heterogenized trimethylsilylation catalyst is easily recovered with a magnet and showed no appreciable loss of activity even after five consecutive runs. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
97.
Majid Moghadam Iraj Mohammadpoor-Baltork Shahram Tangestaninejad Valiollah Mirkhani Hadi Kargar Nafiseh Zeini-Isfahani 《Polyhedron》2009,28(17):3816-3822
In this paper, the biomimetic epoxidation of alkenes catalyzed by tetrakis(p-aminophenyl)porphyrinatomanganese(III) chloride, [Mn(TNH2PP)Cl], supported on functionalized multi-wall carbon nanotubes, MWCNT, is reported. The catalyst, [Mn(TNH2PP)Cl-MWCNT], was used as an efficient and heterogeneous catalyst for epoxidation of alkenes with NaIO4 at room temperature, in the presence of imidazole as an axial ligand. This new heterogenized catalyst was characterized by elemental analysis, FT IR spectroscopy, diffuse reflectance UV–Vis spectrophotometry, scanning electron microscopy and transmission electron microscopy. The biggest advantage of Mn(TNH2PP)Cl-MWCNT is its high reusability in the oxidation reactions, in which the catalyst was reused several times without significant loss of its catalytic activity. 相似文献
98.
Synthesis and characterization of a new porphyrin-polyoxometalate hybrid material and investigation of its catalytic activity 总被引:1,自引:0,他引:1
Araghi M Mirkhani V Moghadam M Tangestaninejad S Mohammdpoor-Baltork I 《Dalton transactions (Cambridge, England : 2003)》2012,41(10):3087-3094
In the present work, the preparation of a new organic-inorganic hybrid material in which tetrakis(p-aminophenylporphyrin) is covalently linked to a Lindqvist structure of polyoxometalate, is reported. This new porphyrin-polyoxometalate hybrid material was characterized by (1)H NMR, FT-IR and UV-Vis spectroscopic methods and cyclic voltammetry. These spectro- and electrochemical studies provided spectral data of the synthesis of this compound. Cyclic voltammetry showed the influence of the porphyrin on the redox process of the polyoxometalate. The catalytic activity of this hybrid material was investigated in the alkene epoxidation with NaIO(4). 相似文献
99.
We give several necessary and sufficient conditions for the existence of the presentation by conjugation for a non-simply laced extended affine Weyl group. We invent a computational tool by which one can determine simply the existence of the presentation by conjugation for an extended affine Weyl group. As an application, we determine the existence of the presentation by conjugation for a large class of extended affine Weyl groups. 相似文献
100.
V. Mirkhani S. Tangestaninejad M. Moghadam M. H. Habibi A. Rostami Vartooni 《Journal of the Iranian Chemical Society》2009,6(4):800-807
The photocatalytic degradation of ortho, para and meta-nitroanilines (ONA, PNA and MNA) was investigated by Ag-TiO2 suspension. The effect of some parameters such as the amount of photocatalyst, irradiation time of UV light, flow rate of O2, pH, and temperature for the Ag-TiO2 photocatalyst was also examined. Degradation of amines was small when the reaction was carried out in the absence of photocatalyst, and negligible in the absence of the UV light. Degradation rate of aniline derivatives decreases with increasing O2 in the system. The effect of pH indicated that effective degradation occurred in alkaline conditions. Degradation kinetics of these aromatic amines can be described by Langmuir-Hinshelwood equation and shows pseudo-first order law. 相似文献