نتایج جستجو برای: supported silyl chromate catalyst
تعداد نتایج: 236684 فیلتر نتایج به سال:
A novel selective route to 1,1-bis(silyl)-1-alkenes has been developed. Sequential one-pot silylative coupling exo-cyclization of 1,2-bis(dimethylvinylsiloxy)ethane followed by the reaction with Grignard reagents leads to the desired 1,1-bis(silyl)ethenes, which are then efficiently coupled in the presence of silver nitrate and palladium acetate with aryl or alkenyl idodides to give the corresp...
A highly diastereoselective approach for the synthesis of protected a,b-dioxyaldehydes derived from (Z)tris(trimethylsilyl)silyl “super silyl” enol ethers is described. A general and highly syn-stereoselective aldol reaction directed by the “super silyl” group catalyzed by triflimide (HNTf2) is developed providing a,bdioxyaldehydes and 1,2,3-triol fragments which can be a useful platform for th...
An efficient and environmental-friendly synthetic route to 1,8-dioxodecahydroacridines derivatives have been developed via multi-component one-pot Hantzsch reaction of various aldehydes and ammonium acetate with 2 equivalents dimedone in the presence of Phosphorus pentoxide supported on aluminaas catalyst under solvent-free conditions. The present approach offersseveral advantages such as short...
in the present study, the synthesis of diethylene triamine supported on cellulose biopolymer as a biodegradable solid basic heterogeneous catalyst was suggested. then, the applicability of the synthesized catalyst cellulose bonded n-propyl diethylene triamine (cbpdeta) was tested for the synthesis of oxindole derivatives, an important class of potentially bioactive compounds. a various series o...
silica supported phosphorus pentoxide (p2o5·sio2) is an efficient catalyst for synthesis of 1,3,5-substituted pyrazoles via the condensation of 1,3-diketones and hydrazines. simplicity of procedure, mild condition, being solvent-free, high yields, and easy workup are some advantages of this protocol.
SCOEL has already issued Summary Documents on both Lead and Lead Compounds (SCOEL/SUM 83) and Hexavalent Chromium Compounds (SCOEL/SUM 86), to which reference is made. On this basis, the present Summary Document on Lead Chromate is focussed on experimental data on the genotoxicity of lead chromate and on the issue of bioavailibility. Specific data on lead chromate published after the latest IAR...
A robust and efficient non-precious metal catalyst for hydrogen evolution reaction is one of the key components for carbon dioxide-free hydrogen production. Here we report that a hierarchical nanoporous copper-titanium bimetallic electrocatalyst is able to produce hydrogen from water under a mild overpotential at more than twice the rate of state-of-the-art carbon-supported platinum catalyst. A...
Carbon-supported platinum (Pt) and palladium (Pd) alloy catalyst has become a promising alternative electrocatalyst for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells. In this work, the synthesis of highly active and stable carbon-supported Pt-Pd alloy catalysts is reported with a room-temperature electron reduction method. The alloy nanoparticles thus prepared show a pa...
SCOEL has already issued Summary Documents on both Lead and Lead Compounds (SCOEL/SUM 83) and Hexavalent Chromium Compounds (SCOEL/SUM 86), to which reference is made. On this basis, the present Summary Document on Lead Chromate is focussed on experimental data on the genotoxicity of lead chromate and on the issue of bioavailibility. Specific data on lead chromate published after the latest IAR...
In this research, a metal oxide nanocatalyst of ZnO supported copper oxide is reported as a highly efficient recyclable catalyst for the chemoselective synthesis of 1,1-diacetates. The catalyst was synthesized by co-precipitation method and characterized by XRD, BET specific surface area, ESEM, EDS and TEM analysis. A wide range of aldehydes, including aromatic and aliphatic aldehydes were conv...
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