Home About us Contact
|
Home About us Contact | ||
|
|
||
Fast Synthesis (fast + synthesis)
Selected AbstractsSimple and Fast Synthesis of New Axially Chiral Bipyridine N,N, -Dioxides for Highly Enantioselective Allylation of AldehydesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2009Aneta Kadl, íková Abstract Unsymmetrically 3,3,-substituted axially chiral bis(tetrahydroisoquinoline) N,N,- dioxides can be prepared in just three steps. They exhibit unique catalytic activity (turnover frequency, enantioselectivity, substrate scope) in the asymmetric allylation of aromatic aldehydes (up to 96% ee). The product of the enantioselective allylation of benzaldehyde served as a building block for the preparation of an intermediate useful in the enantioselective synthesis of diospongines. [source] Fast Synthesis of Nanostructured Microspheres of a Bridged Silsesquioxane via Ultrasound-Assisted Sol,Gel ProcessingMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 2 2009Hernán E. Romeo Abstract Microspheres of a nanostructured bridged silsesquioxane were synthesized by employing ultrasound-assisted self-assembly of a bridged monomer via sol,gel processing. The bridged precursor was synthesized from glycidoxypropyl(trimethoxysilane) (GPMS) (2 mol) and cyclohexylamine (1 mol). The main factor controlling the generation of a stable dispersion of microspheres was the time at which the phase separation of the silsesquioxane was produced during the hydrolytic condensation. An appropriate blend of THF/n -hexane as a solvent enabled to rapidly generate a stable dispersion exhibiting a low polydispersity. The mild reaction conditions produced the nanostructuring of the silsesquioxane characterized by a fine structure in SAXS spectrum. Inorganic domains were arranged in a two-dimensional hexagonal system leading to the formation of cavities in the microspheres which could be employed as host,guest systems in advanced technologies. [source] ChemInform Abstract: Fast Synthesis of Benzofluorenes by Selenium-Mediated Carbocyclizations.CHEMINFORM, Issue 30 2009Sohail A. Shahzad Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] An Expeditious Synthesis of N -Acetylneuraminic Acid ,- C -Glycosyl Derivatives (",- C -Glycosides") from the Anomeric AcetatesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 19 2007Adeline Malapelle Abstract The reductive metallation of the readily available peracetylated derivatives of methyl N -acetylneuraminate 3a and 3b by samarium diiodide without any additive generates the corresponding anomeric samarium(III) organometallics. These intermediates react efficiently with carbonyl compounds under Barbier conditions, providing a fast synthesis of C -ketosides. The ,- and ,-acetates are equally effective, and excellent yields are obtained for coupling with cyclic ketones. The procedure has been conveniently applied to the synthesis of a C -ketoside of N -acetylneuraminic acid with an attached linker, ready to use as a building block in the elaboration of multivalent biological probes. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Determination of the Optimal Conditions for Synthesis of Silver Oxalate NanorodsCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 10 2008M. Pourmortazavi Abstract In this study, an orthogonal array design (OAD), OA9, was employed as a statistical experimental method for the controllable, simple and fast synthesis of silver oxalate nanorods. Ultrafine silver oxalate rods were synthesized by a precipitation method involving the addition of silver ion solution to the oxalate reagent. The effects of reaction conditions, i.e., silver and oxalate concentrations, flow rate of reagent addition and temperature, on the diameter of the synthesized silver oxalate rods were investigated. The effects of these factors on the width of the silver oxalate rods were quantitatively evaluated by the analysis of variance (ANOVA). The results showed that silver oxalate nanorods can be synthesized by controlling the silver concentration, flow rate and temperature. Finally, the optimum conditions for the synthesis of silver oxalate nanorods by this simple and fast method were proposed. The results of ANOVA showed that 0.001,mol/L silver ion concentration, 40,mL/min flow rate for the addition of the silver reagent to the oxalate solution and 0,°C temperature are the optimum conditions for producing silver oxalate nanorods with 107 ± 45,nm width. [source] | ||||||||||