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941.
Akbar Heydari Samad Khaksar Maryam Esfandyari Mahmoud Tajbakhsh 《Tetrahedron letters》2007,48(7):1135-1138
A simple and convenient procedure for direct reductive amination of aldehydes and ketones with sodium borohydride is described. The reaction has been carried out in methanol in the presence of a catalytic amount of H3PW12O40 (0.5 mol %). α,β-Unsaturated aldehydes and ketones can be easily converted into the corresponding allyl alcohols by reaction with H3PW12O40 (0.5 mol %)/NaBH4. 相似文献
942.
Akbar Heydari Roohollah Kazem Shiroodi Hossein Hamadi Maryam Esfandyari Mehrdad Pourayoubi 《Tetrahedron letters》2007,48(33):5865-5868
The commercially available heteropoly acid H3PW12O40 (0.5 mol %) is a very efficient and environmentally benign catalyst for N-tert-butoxycarbonylation of amines (primary, secondary) with di-tert-butyl dicarbonate at room temperature in short reaction times (<10 min). No competitive side products such as isocyanates, ureas, N,N-di-tert-butoxycarbonyls, O-Boc and oxazolidinones were observed. Chiral α-amino alcohols and esters afforded the corresponding N-Boc derivatives chemoselectively in excellent yields. 相似文献
943.
Kamaleddin Haj Mohammad Ebrahim Tehrani Maryam Hashemi Maryam Hassan Farzad Kobarfard Shohreh Mohebbi 《中国化学快报》2016,27(2):221-225
Based on the existing reports on the bioactive isatin derivatives, a number of Schiff bases were synthesized by reacting 5-substituted isatins with bioactive amines/hydrazides and their structures were confirmed using spectroscopic methods such as NMR, IR and mass spectrometry. Furthermore, Nbenzylation of isatin followed by the Schiff base formation furnished a new series of compounds(11a–13c) which allowed the analysis of the effect of isatin N-substitution on the bioactivity of the resulting compounds. The antibacterial activity of the synthesized derivatives was evaluated using a microtiter plate method on a series of gram positive and gram negative bacterial strains. Compounds 2d, 3b, 5c and 6a were among the most potent derivatives against Pseudomonas aeruginosa(MIC = 6.25 μg/m L).Analysis of the structure–activity relationship showed that the incorporation of(thio)urea-based Schiff bases lead to more potent derivatives with a broader spectrum of antibacterial activity. In addition,highly lipophilic compounds such as 11a–12c did not show any measurable antibacterial activity, which implies that an optimal lipophilicity might be an important requirement for the antibacterial activity of the studied isatins. Finally, the finding that hydantoin derivatives of N-benzylisatins(13a–13c) still exhibit some antibacterial activity prompted us to consider exploring the bioactivity of more diverse derivatives of isatin-aminohydantoin Schiff bases(compounds 1a–1d) in our future studies. 相似文献
944.
Investigation of the Effect of Various Substituents on the Density of Tetrazolium Nitrate Salts as Green Energetic Materials 下载免费PDF全文
The substitution effect of various functional groups such as –NO2, –CN, –N3, –NF2, and –NH2 on the density of tetrazolium nitrate salts is investigated through multiple linear regression method. The methodology of this work introduces a new model, which related density of tetrazolium nitrate salts to the number of fluorine and nitrogen atoms, the presence of NF2 groups, NO2 groups, as well as CH3 groups in the structural formula. The new reliable correlation shows that the NF2 and NO2 group can cause increasing the density of tetrazolium nitrate salts, especially NO2, whereas the CH3 group can decrease their density. The new proposed relationship has good reliability and predictability, so it can be used to design new rich nitrogen compounds based on tetrazolium nitrate salts as green energetic materials. These results are also tested for N,N′‐azo‐1,2,4‐triazolium nitrate salts, which is caused to derive another correlation. This correlation shows that the presence of NF2 functional groups increases the density of N,N′‐azo‐1,2,4‐triazolium nitrate salts as well as the value of nO/nC. 相似文献
945.
Roya Mirzajani Maryam Bagheban 《International journal of environmental analytical chemistry》2016,96(6):576-594
Molecular imprinted polymer for determination of malachite green (MG) and fuchsine basic (FU) dyes by spectrophotometry has been used, to develop a novel simultaneous extraction and preconcentration method. Molecularly imprinted layer-coated nano-alumina (MIP@Nano-Al2O3) as adsorbent was prepared by surface molecular imprinting technique, and characterised by FTIR spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis (EDAX) and thermogravimetric analysis (TGA). The method is based on simultaneous extraction of MG and FU dyes from aqueous solution by using molecularly imprinted polymer and measuring the absorbance at 617 and 546 nm for MG and FU, respectively. Parameters which affect the extraction efficiency such as pH, volume of eluent and amount of adsorbent were investigated and optimised. Linear calibration curves were obtained in the range of 2–750 ng mL?1 for MG and 1–240 ng mL?1 for FU under optimum conditions. Detection limit based on three times the standard deviation of the blank (3Sb) was 0.655 and 0.245 ng mL?1 (n = 10) for MG and FU, respectively. The relative standard deviation (RSD) for 100 ng mL?1 of MG and FU was 2.35 and 3.06% (n = 7), respectively. The method was applied to the simultaneous determination of the dyes in different seafood and environmental water samples. 相似文献
946.
947.
Maryam Mirza-Aghayan Rabah Boukherroub Max Koenig 《Journal of organometallic chemistry》2005,690(4):1028-1032
This paper describes the photochemical and the thermal isomerization of s-cis(E,E) 1,1-diphenly-3,4-bis(trimethylsilylmethylene)-1-silacyclopentane (1a). Under thermal conditions a 1,3-sigmatropic of the methylene hydrogen occurs, yielding the s-trans isomer (1b). The photochemical irradiation of (1a) at 300 nm for 1 h in deoxygenated benzene gives the corresponding s-cis(E,Z) isomer (1c) and then the s-cis(Z,Z) isomer (1d) after prolonged irradiation (3 h). There was no evidence for the formation of the corresponding cyclobutene resulting from the ring closure of the exocylic diene. 相似文献
948.
Hossein Aghabozorg Abolghasem Moghimi Faranak Manteghi Maryam Ranjbar 《无机化学与普通化学杂志》2005,631(5):909-913
Starting with a zirconium salt and LH2 , (pydaH2)2+(pydc)2?, (pyda=2, 6‐pyridinediamine; pydcH2=2,6‐pyridinedicarboxylic acid), as a 1:1 proton transfer self‐associated compound, two different compounds were resulted. One of them is a new complex of ZrIV with a flat pyridine containing ligand and structure of (pydaH)2[Zr(pydc)3] · 5H2O (1) and the other, (pydaH)+(NO3)? (2) is an ion pair with no zirconium ion. The zirconium(IV) complex (1) is crystallized in triclinic system with space group and Z = 2, the crystallographic parameters are: a = 10.612(5) Å, b = 10.617(5) Å, c = 16.815(8) Å, α = 103.654(9)°, β = 95.821(9)°, γ = 98.891(9)° and R‐value for 16767 collected reflections is 0.0592. The ion pair (2) has crystals of monoclinic system with P21 space group and Z = 2. Its crystallographic parameters are: a = 3.6227(11) Å, b = 10.034(4) Å, c = 10.296(4) Å, β = 93.422(9)° and R‐value for 4031 collected reflections is 0.0521. The two compounds were characterized with elemental analysis, ESI/MS, NMR and IR spectroscopy. 相似文献
949.
α‐Aminonitriles as key intermediates for the preparation of α‐amino acid derivatives, amides, diamines, peptides, proteins and heterocycles were synthesized through methylarene oxidation in the Strecker reaction using a unique combination of KI/ZnFe2O4 as the best catalyst and aqueous tert‐butyl hydroperoxide as oxidant. A wide range of amines and methylarenes were converted to the corresponding products. Operational simplicity, short reaction time and recyclability of the catalyst are advantages of this protocol. 相似文献
950.
Behnam Mahdavi Sania Saneei Maryam Qorbani Mohsen Zhaleh Akram Zangeneh Mohammad Mahdi Zangeneh Elham Pirabbasi Naser Abbasi Hori Ghaneialvar 《应用有机金属化学》2019,33(11)
LamZiziphora clinopodioides Biosynthesis of metal nanoparticles using plant medicine is under exploration is due to wide biomedica applications and research interest in nanotechnology, the recent study was assessing green synthesis of zinc nanoparticle using ), the use of plant material Ziziphoraleaves extract (ZnNPs@ not only makes the process eco‐friendly but also the abundance makes it more economical. Also, in this study, Vis. and– were characterized using different techniques including UVZiziphora were synthesized in aqueous medium using the plant extract as stabilizing and reducing agents. The synthesized ZnNPs@Ziziphora conditions. ZnNPs@in vivo and in vitro under Ziziphorawe investigated the therapeutical properties of ZnNPs@ FT‐IR spectroscopy, . SEM images exhibited a uniform spherical morphology in size of 32.34 Thermal Gravimetric Analysis (TGA)ray diffraction (XRD), scanning electron microscopy (SEM), and Energy Dispersive X‐ray Spectrometry (EDS), and‐X Escherichia coli, and Pseudomonas aeruginosa, Salmonella typhimurium part of this study, these nanoparticles indicated excellent antibacterial properties against Gram‐negative bacteria (in vitronm for the biosynthesized nanoparticles. In the biological , andCandida krusei, Candida albicans, Candida glabrata), antifungal potentials against Bacillus subtilis, andStaphylococcus aureus, Streptococcus pneumoniaO157:H7) and Gram‐positive bacteria ( leaves aqueous extract can be used to yield zinc nanoparticles with a significant amount of antibacterial, antifungal, antioxidant, and cutaneous wound healing properties without any cytotoxicity.Z. clinopodioides ointment ameliorated the cutaneous wounds with increasing the levels of wound contracture, vessel, hydroxyl proline, hexosamine, hexuronic acid, fibrocyte, and fibrocytes/fibroblast rate and decreeing the wound area, total cells, and lymphocyte compared to other groups in rats. The results of UV, FT‐IR, XRD, FE‐SEM, EDS, and TGA confirm that the Ziziphora part of our experiment, ZnNPs@in vivo, non‐cytotoxicity effect against human umbilical vein endothelial cells, and antioxidant activity against DPPH. In the biological Candida guilliermondii 相似文献