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31.
Umar Farid Maria Luisa Aiello Prof. Stephen J. Connon 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(43):10074-10079
A new catalytic methodology was developed to promote an efficient one-pot kinetic resolution of racemic aldehydes with selectivity (s*) of up to 91 (99:1 d.r., >99 % ee) in a cycloaddition reaction with enolizable anhydrides to afford dihydroisocoumarin products (a core prevalent in natural products and molecules of medicinal interest) containing three contiguous stereocentres. 相似文献
32.
Nehal F. Farid Ibrahim A. Naguib Nessreen S. Abdelhamid Basma H. Anwar Maimana A. Magdy 《Journal of separation science》2020,43(12):2330-2337
A novel ecofriendly, cost and time saving high‐performance thin‐layer chromatographic method was developed and validated for simultaneous determination of metoclopramide, ergotamine, caffeine, and paracetamol in bulk and pharmaceutical formulation. The separation was carried out on silica gel plates, using ethyl acetate:ethanol:ammonia (9:1:0.1, v/v/v) as a developing system. Ultraviolet detection was carried out at 272 nm. The resulting retention times were 0.15, 0.36, 0.49, and 0.74 min for metoclopramide, ergotamine, caffeine, and paracetamol, respectively. The greenness profile assessment was achieved to the proposed method to evaluate its greenness characters to the environment with acceptable results. Validation parameters were checked according to International Conference of Harmonization guidelines to achieve the international requirements for quality control analysis of the proposed drugs. 相似文献
33.
Farid Azizian James S. Pizey 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-2)
Abstract 3-Thietanones have been prepared by treating certain ketones with thionyl chloride or sulphur dichloride. In the case of ketones containing a tertiary alpha proton the initial product obtained on treatment with thionyl chloride is the sulphinyl chloride which then cyclises to the thietanone. 相似文献
34.
Treatment of glycosyl halides with NaN3 in aqueous acetone or acetonitrile is a convenient method for the stereoselective synthesis of 1,2-trans-per-O-acetyl-glycosyl azides. 相似文献
35.
36.
Structure–reactivity studies of chloro and isothiocyanato diorganotin (IV) complexes based on multidentate N‐donor ligands: Synthesis,spectral characterization and crystal structures
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The reaction of [SnMe2Cl2] with the bidentate ligand 4,7‐phenanthroline (4,7‐phen) resulted in the formation of [SnMe2Cl2 (4,7‐phen)]n ( 1a ) which is probably a polymeric chain in solution. On the other hand, the reaction of [SnEt2Cl2] with 4,7‐phen afforded the complex [Sn2Et4Cl4 (κ1‐N‐4,7‐phen)2(μ‐κ2‐N,N‐4,7‐phen)] ( 1b ) which dissociates in dimethylsulfoxide solution. The reaction of [SnR2Cl2] (R = Me, Et) with 2,2′‐biquinoline (biq) yielded the complexes [SnMe2Cl2 (κ2‐N,N‐biq)] ( 2a ) and [SnEt2Cl2 (κ1‐N‐biq)2] ( 2b ) in the solid state. Moreover, the reaction of [SnR2Cl2] (R = Me, Et) with the tridentate ligand 4′‐(2‐furyl)‐2,2′:6′,2″‐terpyridine (ftpy) resulted in the formation of ionic penta‐ and hexa‐coordinated tin complexes [SnMe2Cl (ftpy)][SnMe2Cl3] ( 3a ) and [SnEt2Cl (ftpy)]Cl ( 3b ). The reaction of [SnMe2 (NCS)2] with ftpy afforded the hepta‐coordinated complex [SnMe2 (NCS)2(ftpy)] ( 4a ). The products were fully characterized using elemental analysis, and infrared, UV–visible, multinuclear (1H, 13C, 119Sn) NMR, DEPT‐135°, HH‐COSY and HSQC NMR spectroscopies. The crystal structure of complex 3a reveals that it contains the simultaneous presence of penta‐ and hexa‐coordinated tin (IV) atoms. Notably, the crystal structure of complex 4a shows that tin (IV) is hepta‐coordinated in a pentagonal bipyramidal geometry SnC2N5 by three nitrogen atoms of ftpy, two nitrogen atoms of NCS? and two Me groups with trans‐[SnMe2] configuration. These data indicate the influence of halide or pseudo‐halide group on the coordination number and geometry of tin. Hirshfeld surface analysis and two‐dimensional fingerprint plots were calculated for 3a and 4a which show the π–π interaction between molecules in the solid is relatively weak. 相似文献
37.
Nasser M. Hosny Farid I. El-Dossoki Mohsen M. Mostafa 《Phosphorus, sulfur, and silicon and the related elements》2013,188(2):402-410
New metal complexes derived from the reaction of N-[(phenylamino)thioxomethyl] hydrazino carbonyl methyl pyridinium chloride (H2L; PTHMPC) with some metal salts of the general formula MX2 [(X = Cl? and/or CH3COO?; M = Cd(II), UO2(II), Mn(II) and Zr(IV)] were synthesized and characterized by elemental analyses, spectral analyses (IR, UV-vis., 1H NMR), thermal analyses (TGA, DTG), and conductance and magnetic measurements. The results showed that the ligand exists in metal complexes either in the keto form or in the enol form. Moreover, the IR spectral data suggest that the acetate ion behaves in a monodentate manner. Semi-empirical calculations ZINDO/1, PM3, and AM1 have been used to study the molecular geometry and the harmonic vibrational spectra of the ligand and its metal complexes with the purpose of assisting the experimental assignment of the complexes. Generally, there is an agreement between the observed and the calculated spectra. Finally, the thermodynamic parameters (ΔE*, ΔH, ΔG, and ΔS) have been calculated from the data of thermal analyses (TGA and DTG). Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. 相似文献
38.
Il’yas S. Nizamov Ilnar D. Nizamov Farid D. Yambushev Olga V. Bolshakova Gulnur G. Sergeenko Vladimir F. Mironov 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1436-1442
Abstract The reactions of geraniol, nerol, and linalool with N,N-diethylamido O,O-propylenephosphite and diethyl chlorophosphite were studied. On the basis of these studies, new dienyl diprenoid phosphite esters were obtained. GRAPHICAL ABSTRACT 相似文献
39.
Arash Ghorbani-Choghamarani Mohammad Soleiman-Beigi Farid Noormohammadi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1665-1672
Abstract Trimethylphenylammonium tribromide has been introduced as a versatile and new oxidizing agent for the preparation of disulfides and sulfoxides from thiols and sulfides, respectively. The reaction progress is simple, and proceeds under mild and homogenous conditions in ambient temperature. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. GRAPHICAL ABSTRACT 相似文献
40.
Farid Ichou Denis Lesage Xavier Machuron‐Mandard Christophe Junot Richard B. Cole Jean‐Claude Tabet 《Journal of mass spectrometry : JMS》2013,48(2):179-186
Control of the ion internal energy in mass spectrometry is needed to establish a workable mass spectral library. The purpose of this study is to understand and to compare the pressure effects on the collision‐induced dissociation (CID) spectrum pattern recorded using triple quadrupole instruments. The monoprotonated Leucine enkephalin [YGGFL, H+] was used as a thermometer molecule to calibrate the electrospray ionization (ESI) and the CID internal energies deposited on the molecular species and the time scale of ion decompositions. The survival yield and the ratio of a4/b4 fragment ions were mainly monitored. The energy uptake for the ESI source geometry used in our study has no impact on the CID spectrum fingerprint. The collision cell pressure for the [YGGFL, H+] has a major influence on the SY curves slope and on the experimental time scale. To demonstrate the pressure effect on internal energy distribution, three models (threshold, thermal and collisional) based on RRKM theory were built using the Masskinetics software. As a result, the limit of each model is discussed, and the investigation demonstrates that the thermal model, using truncated Maxwell‐Boltzmann internal energy distribution, is well‐suited for simulating the experimental data at high pressure widely used in the analytical conditions. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献