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2-Bromo-6-lithiopyridine adds stereoselectively to the β-face of 1,2;5,6-di-O-isopropylidene-α-D-glucofuranos-3-ulose (2) to provide compound 5 in 50% yield as a single diastereomer. Compound 5 can be coupled to form novel C2-symmetric 2,2′-bipyridine 7, the first example of a C2-symmetric bipyridine that derives chirality from glucose. 相似文献
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Methyl acetoacetate and 2,4-pentanedione dianions were condensed with aldehydes and ketones to afford a 1,3,5-trioxygenated carboskeleton. Intramolecular cyclization of the aldol adducts delivered the title compounds in good yield. 相似文献
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Morteza Rezaei Talarposhti Tristan Asset Samuel T. Garcia Yechuan Chen Sergio Herrera Sheng Dai Eric J. Peterson Kateryna Artyushkova Iryna Zenyuk Plamen Atanassov 《Chemphyschem》2020,21(12):1331-1339
We investigated the oxygen reduction reaction (ORR) mechanism on Pt nanoparticles (NPs) dispersed on several carbon blacks with various physicochemical properties (i. e. specific surface ranging from 80 to 900 m2 g−1, different graphitization degree, etc.). Using the kinetic isotope effect (KIE) along with various electrochemical characterizations, we determined that the rate determining step (RDS) of the ORR is a proton-independent step when the density of Pt NPs on the surface of the carbon support is high. Upon decrease of the density of Pt NPs on the surface, the RDS of the ORR starts involving a proton, as denoted by an increase of the KIE >1. This underlined the critical role played by the carbon support in the oxygen reduction reaction electrocatalysis by Pt supported on high surface area carbon. 相似文献
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Carolina Resmini Melo Elidio Angioletto Humberto Gracher Riella Michael Peterson Márcio Roberto Rocha Aline Resmini Melo Luciano Silva Susane Strugale 《Journal of Thermal Analysis and Calorimetry》2012,109(3):1341-1345
Research focused on the transformation and utilization of industrial wastes into products of commercial interest plays an increasingly important role. Residual pulp can become useful in the manufacture of different materials, providing high value to this waste and reducing its environmental impact when disposed of improperly in the environment. The main constituents of this waste are kaolin and calcium carbonate (CaCO3). Starting from kaolin, metakaolin can be produced by calcination of the residue at 630?°C for 2?h in a rotary reactor with air flow, followed by solubilization with hydrochloric acid to remove the CaCO3. The development of technological alternatives aimed at the reuse of certain wastes can result in applications of real economic interest to the chemical industry and ceramics and glass, which is the case in this study. The raw material and metakaolin obtained were analyzed by thermogravimetric analysis and derivative thermogravimetric analysis, X-ray diffraction, and X-ray fluorescence spectroscopy with promising results. This is because metakaolin was obtained free of contamination by other materials. 相似文献
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Detoxification of Chemical Warfare Agents Using a Zr6‐Based Metal–Organic Framework/Polymer Mixture 下载免费PDF全文
Dr. Su‐Young Moon Emmanuel Proussaloglou Gregory W. Peterson Dr. Jared B. DeCoste Morgan G. Hall Dr. Ashlee J. Howarth Prof. Joseph T. Hupp Prof. Omar K. Farha 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(42):14864-14868
Owing to their high surface area, periodic distribution of metal sites, and water stability, zirconium‐based metal–organic frameworks (Zr6‐MOFs) have shown promising activity for the hydrolysis of nerve agents GD and VX, as well as the simulant, dimethyl 4‐nitrophenylphosphate (DMNP), in buffered solutions. A hurdle to using MOFs for this application is the current need for a buffer solution. Here the destruction of the simulant DMNP, as well as the chemical warfare agents (GD and VX) through hydrolysis using a MOF catalyst mixed with a non‐volatile, water‐insoluble, heterogeneous buffer is reported. The hydrolysis of the simulant and nerve agents in the presence of the heterogeneous buffer was fast and effective. 相似文献