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991.
Rajesh Malhotra Amit Ghosh Rajib Ghosh Sagar Chakrabarti Swarup Dutta Tushar K. Dey Subho Roy Sourav Basu Saumen Hajra 《Tetrahedron: Asymmetry》2011,22(14-15):1522-1529
A scalable asymmetric synthesis of trans-2-amino-6,7-dimethoxy-1-phenyltetralin 2 and its N-nosyl derivative 12 have been achieved from Garner aldehyde derived from easily available d-serine using a stereoselective PhMgBr addition, Wittig reaction and TFA-mediated Friedel–Crafts cyclization as the key steps. The synthesis of dihydrexidine is accomplished from the N-nosyl-2-amino-1-phenyltetralin 12. 相似文献
992.
Meenakshi Choudhary Rafique Ul Islam Michael J Witcomb Motlatsi Phali Kaushik Mallick 《应用有机金属化学》2013,27(9):523-528
We report here a method for the preparation of polymer hollow spheres in which 3‐aminoquinoline (3‐AQ) and palladium acetate were used as precursors. During the reaction 3‐AQ was oxidized and formed poly(3‐AQ). IR and Raman spectra provided information on the chemical structure of the polymer. The oxidation state of palladium was confirmed by X‐ray photoelectron spectroscopic analysis. Transmission and scanning electron microscopy were used to determine the size and morphology of the polymer. The palladium–poly(3‐AQ) supramolecular system was used as an effective catalyst for the Suzuki coupling reaction of aryl halides in the absence of a phosphine ligand. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
993.
Gita Seth Vijaya Kabra Jasvinder Kaur Ritu Mathur Priti Kaushik 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5):1001-1010
New tetracoordinated complexes of Zn (II) have been synthesized by the reaction between zinc chloride and 3-methyl-2-benzothiazolylidenamido-thiophosphoryl dichloride (L1), (3-methyl-2-benzothiazolylidenamido)-bis-(diethylamido)thiophosphate (L2), 3-benzyl-2-benzothiazolylidenamido thiophosphoryl dichloride (L3), and (3-benzyl-2-benzothiazolylidenamido)-bis-(diethyl-amido) thiophosphate (L4) in a 1:1 ratio. The complexes have been isolated and characterized by elemental analysis, electrical conductivity, and mass and IR spectral studies. The stability constants of these complexes also have been determined in aqueous solution by spectrophotometric methods. 相似文献
994.
Summary A simple, economical and efficient HPLC method has been developed for the separation and determination of the individual glucosinolates
in rapessed and mustard. The method involves single-step extraction of glucosinolates with boiling water and separation of
the individual glucosinolates on a Novapack RP-18 column (3.9 mm ×150mm) with 0.2 M ammonium sulphate as mobile phase. Peaks
were monitored at 229 nm. All major glucosinolates could be eluted within 10 min. The method proved effective for routine
analysis of glucosinolates. 相似文献
995.
This paper continues our recent work on the relationship between discrete contact interactions at the microscopic scale and continuum contact interactions at the macroscopic scale(Hulikal et al., J. Mech. Phys. Solids 76,144–161, 2015). The focus of this work is on adhesion. We show that a collection of a large number of discrete elements governed by a threshold-force based model at the microscopic scale collectively gives rise to continuum fracture mechanics at the macroscopic scale. A key step is the introduction of an efficient numerical method that enables the computation of a large number of discrete contacts. Finally,while this work focuses on scaling laws, the methodology introduced in this paper can also be used to study roughsurface adhesion. 相似文献
996.
Suchita Kalele Ravi Dey Neha Hebalkar J. Urban S. W. Gosavi S. K. Kulkarni 《Pramana》2005,65(5):787-791
Abstract Nearly monodispersed particles of silica were prepared and coated with uniform layers of titanium dioxide in anatase phase
by hydrolysis and condensation of titanium butoxide. The coating thickness could be altered by adjusting the concentration
of reactants (titanium butoxide and water) and the amount of added silica particles. Different coating thicknesses were deposited
and studied using optical absorption spectroscopy, electron microscopy and Fourier transform infra-red spectroscopy. It was
found that silica particles of size 170 ±5 nm were coated with 23±5 nm thick layer of titanium dioxide. Alternatively titania
particles of size 340±5 nm were synthesized by controlled hydrolysis of titanium ethoxide in the presence of sodium chloride.
These particles were further coated with 135±5 nm thick layer of silica to investigate changes in properties after changing
the shell material 相似文献
997.
E. Schaefer F. M. Schemjakin W. A. Wolkowa A. K. Babko I. Martyntschenko A. Schimko B. B. Dey S. Rengachari M. V. Sitharaman J. Rzymkowski T. M. Kolthoff G. L. Maheshwari J. B. Tha T. Ilahi A. Rohmann B. Singh T. I. Malik S. Kilpi B. B. Owen Louise Foering H. E. Bent N. B. Keevil Ch. K. Ingold H. G. G. Mohrhenn E. Cattelain C. Couchet 《Analytical and bioanalytical chemistry》1941,122(9-10):354-368
998.
Parametric amplification was shown to take place in the response of an ensemble of nonlinear classical oscillators upon the interaction with a second pulse. 相似文献
999.
A series of [Cp2TiL]+[RR′NCS2]? complexes, where L is the conjugate base of acetylacetone, benzoylacetone or 8-hydroxyquinoline and R = CH3, R′ = C6H5CH2; R = C2H5, R′ = C6H4CH3; R = H, R′ = C5H9; RR′ = C6H12, have been synthesised in aqueous medium by the reaction of [Cp2TiL]+Cl? with RR′NCS?2Na+. Conductivity measurements in nitrobenzene solution indicate that these complexes are electrolytes. Both the IR and NMR studies demonstrate that the ligand L is chelating in all these complexes. Consequently, tetrahedral coordination about the titanium atom is proposed. In addition to these studies, elemental analyses and magnetic susceptibility have been carried out for these complexes. 相似文献
1000.