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51.
Current Applications of Suzuki–Miyaura Coupling Reaction in The Total Synthesis of Natural Products: An update 下载免费PDF全文
Suzuki‐Miyaura Coupling Reaction (SMCR) has been extensively used in the total synthesis of natural products. We underscored these achievements in a report published in Tetrahedron up to 2012. Since then, there has been tremendous growth in this field and numerous articles have been published after 2012. In this review, we tried to go insight and highlight the current developments in the applications of SMCR as a key and strategic step (steps) in the total synthesis of biologically active natural products accomplished and reported from 2012 till date. 相似文献
52.
Dodecatungstocobaltate heteropolyanion encapsulation into MIL‐101(Cr) metal–organic framework scaffold provides a highly efficient heterogeneous catalyst for methanolysis of epoxides 下载免费PDF全文
Afsaneh Marandi Shahram Tangestaninejad Majid Moghadam Valiollah Mirkhani Adam Mechler Iraj Mohammadpoor‐Baltork Farnaz Zadehahmadi 《应用有机金属化学》2018,32(2)
A heterogeneous catalyst was synthesized by encapsulation of a Keggin‐type heteropolytungstate, potassium dodecatungstocobaltate trihydrate, K5[CoW12O40]·(Co‐POM), into chromium(III) terephthalate (MIL‐101). Encapsulation was achieved via a ‘build bottle around ship’ strategy in aqueous media, following a hydrothermal method. The structure of the resulting crystalline solid was characterized using X‐ray diffraction, correlated with Fourier transform infrared and UV–visible spectroscopy. The metal content was analysed using optical emission spectroscopy. Transmission electron microscopy was used to measure particle size and N2 adsorption in a Brunauer–Emmett–Teller instrument to characterize the specific surface area. The catalytic activity was investigated using methanolysis of epoxides under mild conditions as a test reaction. The turnover frequency of the heterogeneous Co‐POM@MIL‐101 catalyst was more than 20 times higher than that of the homogeneous Co‐POM catalyst. The Co‐POM@MIL‐101 catalyst was reused several times with negligible leaching of Co‐POM and with no considerable loss of its initial efficiency. The simplicity of preparation, extraordinary stability and high reactivity make Co‐POM@MIL‐101 an exceptional catalytic matrix that is easily separable from reaction media. 相似文献
53.
54.
Sina Khani Gholamali Atefi Afsaneh Soleimani 《Journal of Dispersion Science and Technology》2013,34(10):1371-1376
This investigation describes unsteady, pulsatile, laminar, and locally fully developed blood flow velocity and rotation fields during cardiac cycle in the femoral artery using Cosserat continuum mechanics approach. After solving the continuity, linear momentum, and angular momentum equations for flow of blood through artery, the time and position dependent velocity and rotation fields have been calculated. It is shown that the maximum values of velocity occur at the inlet core, while the maximum values of rotation occur on the arterial boundary. It is also demonstrated that the flow of blood in artery is laminar and a good agreement with existing data is established. A time dependent Gaussian equation for non-Newtonian blood viscosity coefficient γv has also been found. 相似文献
55.
Hassan Hosseini-Monfared Afsaneh Farrokhi Sohaila Alavi Peter Mayer 《Transition Metal Chemistry》2013,38(3):267-273
A mononuclear dioxo vanadium(V) complex of a hydrazone ONO donor ligand, [VVO2(L1)] (1), was synthesized by the reaction of V2O5 and terephthalic acid with H2L1 in 1:1:1 mol ratio, while an oxo-bridged bis(vanadium(IV)oxo) complex, [μ 2–O–{VIVO(L2)}2] (2), was synthesized by the treatment of isonicotinic acid hydrazide, salicylaldehyde and CoSO4·7H2O with bis(acetylacetonato)oxovanadium(IV) (H2L1 = isonicotinic acid(2-hydroxy-benzylidene)-hydrazide, H2L2 = isonicotinic acid (1-methyl-3-oxo-butylidene)-hydrazide). The complexes were characterized by elemental analyses and spectroscopic methods. The crystal structure of complex 2 was determined by X-ray analysis. The complexes were tested as catalysts for the oxidation of cycloalkenes and benzyl alcohol using H2O2 as terminal oxidant. Excellent selectivity was achieved in the oxidation of cyclohexene. 相似文献
56.
In the present paper, the electrochemical reduction of nitrite at a hemoglobin modified pencil lead electrode (Hb/PLE) is described. The electrochemical properties of nitrite were studied by cyclic voltammetry and chronoamperometry. Results showed that the hemoglobin film has an excellent electrochemical activity towards the reduction of nitrite. By using voltammetric and chronoamperometric methods, α, nα and n were calculated. Then the ability of the electrode for nitrite determination was investigated using differential pulse voltammetry. The electrocatalytic reduction peak currents were found to be linear with the nitrite concentration in the range from 10 to 220 µM with a detection limit of 5 µM. The relative standard deviation is 2 % for 3 successive determinations of a 100 µM nitrite solution. This modified electrode was successfully used for the detection of low amounts of NO2? in spinach sample and a spiked sample of tap water. 相似文献
57.
Mohammad Mazloum-Ardakani Mahboobe Abolhasani Bibi-Fatemeh Mirjalili Mohammad Ali Sheikh-Mohseni Afsaneh Dehghani-Firouzabadi Alireza Khoshroo 《催化学报》2014,35(2):201-209
A chemically modified carbon paste electrode (CPE), consisting of 2,2''-[(1E)-(1,2-phenylenebis(azanylylidene)] bis(methanylylidene)]bis(benzene-1,4-diol) (PBD) and multiwalled carbon nanotubes (CNTs), was used to study the electrocatalytic oxidation of dopamine using cyclic voltammetry, chronoamperometry, and differential pulse voltammetry (DPV). First, the electrochemical behavior of the modified electrode was investigated in buffer solution. Then the diffusion coefficient, electrocatalytic rate constant, and electron-transfer coefficient for dopamine oxidation at the surface of the PBD-modified CNT paste electrode were determined using electrochemical approaches. It was found that under optimum conditions (pH = 7.0), the oxidation of dopamine at the surface of such an electrode occurred at about 200 mV, lower than that of an unmodified CPE. DPV of dopamine at the modified electrode exhibited two linear dynamic ranges, with a detection limit of 1.0 μmol/L. Finally, DPV was used successfully for the simultaneous determination of dopamine, uric acid, and folic acid at the modified electrode, and detection limits of 1.0, 1.2, and 2.7 μmol/L were obtained for dopamine, uric acid, and folic acid, respectively. This method was also used for the determination of dopamine in a pharmaceutical preparation using the standard addition method. 相似文献
58.
Niloofar Moheimanian Jahan Bakhsh Raoof Afsaneh Safavi Reza Ojani 《Journal of the Iranian Chemical Society》2014,11(4):1217-1222
A novel nitrite biosensor was constructed by simultaneous immobilization of hemoglobin (Hb) and a room temperature ionic liquid, octylpyridinium chloride ([OcPy][Cl]), on multi-walled carbon ionic liquid electrode (MWILE). The direct electron transfer of Hb showed a pair of redox peaks with a formal potential of ?0.187 V vs. Ag/AgCl in pH 5.0 acetate buffer solution. Nitrite (NO2 ?) catalysis on the modified electrode was investigated by cyclic voltammetry and amperometry. The biosensor exhibited a wide linear range for NO2 ? detection from 0.01 to 15 mM, with a detection limit (3σ) of 1.46 μM. MWILE provided an excellent matrix for protein immobilization and biosensor fabrication which could be used for the determination of NO2 ? with a low detection limit, fast response, long linearity, and excellent sensitivity. 相似文献
59.
Peyman Salehi Mohammad M. Khodaei Mohammad A. Zolfigol Afsaneh Keyvan 《Monatshefte für Chemie / Chemical Monthly》2002,133(10):1291-1295
Summary. Crossed aldol condensations of ketones with aromatic aldehydes are carried out efficiently in the presence of magnesium hydrogensulfate
under solvent-free conditions in good to excellent yield without the occurrence of any self-condensation. Similar reactions
in solution do not proceed satisfactorily.
Corresponding authors. E-mail: p-salehi@cc.sbu.ac.ir
Received September 20, 2001. Accepted (revised) January 16, 2002 相似文献
60.
Peyman Salehi Mohammad M. Khodaei Mohammad A. Zolfigol Afsaneh Keyvan 《Monatshefte für Chemie / Chemical Monthly》2002,27(11):1291-1295
Crossed aldol condensations of ketones with aromatic aldehydes are carried out efficiently in the presence of magnesium hydrogensulfate under solvent-free conditions in good to excellent yield without the occurrence of any self-condensation. Similar reactions in solution do not proceed satisfactorily. 相似文献