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Polyfunctional quinolines were synthesized using Friedlander method catalyzed by molecular iodine in high yields at 60 °C under solvent‐free conditions. 相似文献
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CoFe2O4@SiO2‐CPTES‐Guanidine‐Cu(II) magnetic nanoparticles were synthesized and used as a new, inexpensive and efficient heterogeneous catalyst for the synthesis of polyhydroquinolines and 2,3‐dihydroquinazoline‐4(1H)‐ones and for the oxidation of sulfides. The structure of this nanocatalyst was characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, vibrating sample magnetometry, thermogravimetric analysis, X‐ray diffraction and inductively coupled plasma optical emission spectrometry. Simple preparation, high catalytic activity, simple operation, high yields, use of green solvents, easy magnetic separation and reusability of the catalyst are some of the advantages of this protocol. 相似文献
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N,N,N',N'-Tetrabromobenzene-1,3-disulfonamide (TBBDA)/triphenylphosphine and N,N,N',N'-tetra- chlorobenzene-1,3-disulfonamide (TCBDA)/triphenylphosphine have been introduced as highly efficient systems for the versatile conversion of aldoxime derivatives into nitriles. The process reported here is operationally simple and reactions have been mildly performed in dichloromethane at room temperature. 相似文献
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Mustafa Aghazadeh Abbas-Ali Malek Barmi Hamid Mohammad Shiri 《Russian Journal of Electrochemistry》2013,49(4):344-353
Nanoparticles, nanospheres and nanorods of Y(OH)3 and Y2O3 were prepared via cathodic electrodeposition from chloride bath through applying different current densities. First, yttrium hydroxide precursors were cathodically grown on the cathode surface at the current densities of 2, 1, 0.5, 0.25 and 0.1 mA cm?2. Then hydroxide powders were heat-treated at 600°C for 3 h. The composition, crystal structure and morphology of the prepared oxide and hydroxide products were investigated by means of differential scanning calorimetery (DSC), X-ray diffraction (XRD), scanning and transmission electron microscopes (SEM and TEM) and FT-IR spectroscopy. Mechanism of base electrogeneration at the applied conditions, and intercalation of chloride ions in the deposit structure during the electrodeposition were proposed and confirmed by the XRD and TG analyses. The results showed that the structural and morphological properties of the products are directly dictated by the applied current density and it can be recognized as the main factor affecting on the cathodic electrodeposition of Y2O3. 相似文献
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The sodium salts of the conjugated bases of uracils undergo highly chemoselective O4-monoalkylation when treated with various alkyl halides in dry DMF, while the use of methyl iodide results in N1+N3-dimethylation. Theoretical evaluations of the chemo- and regioselectivity along with X-ray crystallographic data are presented. 相似文献
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Dr. Sofia Curland Dr. Christoph Allolio Leah Javitt Shiri Dishon Ben-Ami Dr. Isabelle Weissbuch Dr. David Ehre Prof. Dr. Daniel Harries Prof. Dr. Meir Lahav Prof. Dr. Igor Lubomirsky 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(36):15705-15709
Electrofreezing experiments of super-cooled water (SCW) with different ions, performed directly on the charged hemihedral faces of pyroelectric LiTaO3 and AgI crystals, in the presence and in the absence of pyroelectric charge are reported. It is demonstrated that bicarbonate (HCO3−) ions elevate the icing temperature near the positively charged faces. In contrast, the hydronium (H3O+) slightly reduces the icing temperature. Molecular dynamics simulations suggest that the hydrated trigonal planar HCO3− ions self-assemble with water molecules near the surface of the AgI crystal as clusters of slightly different configuration from those of the ice-like hexagons. These clusters, however, have a tendency to serve as embryonic nuclei for ice crystallization. Consequently, we predicted and experimentally confirmed that the trigonal planar ions of NO3− and guanidinium (Gdm+), at appropriate concentrations, elevate the icing temperature near the positive and negative charged surfaces, respectively. On the other hand, the Cl− and SO42− ions of different configurations reduce the icing temperature. 相似文献
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Shiri Artstein-Avidan Omer Friedland Vitali Milman Sasha Sodin 《Israel Journal of Mathematics》2006,156(1):141-155
We present a quantitative form of the result of Bai and Yin from [2], and use to show that the section of ℓ
1
(1+δ)n
spanned byn random independent sign vectors is with high probability isomorphic to euclidean with isomorphism constant polynomial in
δ−1.
Partially supported by BSF grant 2002-006.
Supported by the National Science Foundation under agreement No. DMS-0111298.
Supported in part by the Israel Science Academy. 相似文献
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