|Palladium-Catalyzed Three-Component Synthesis of Phenothiazines|
Troels Dahl, Christian Wenzel Tornøe, Benny Bang-Andersen, Poul Nielsen and Morten Jørgensen
The formation of aromatic carbon-heteroatom bonds has traditionally been achieved by nucleophilic aromatic substitution or via the copper-mediated Ullman reaction. The palladium-catalyzed formation of aromatic C-N bonds extensively developed by Hartwig and Buchwald has provided a powerful alternative. While the aryl amination reaction is applicable even to aryl chlorides and activated phenols, the analogous C-O and C-S bond forming reactions have attracted less attention.
|High Throughput Microwave Synthesis of Metal Organic Framework (MOF) Libraries|
Neil L. Campbell, Jake Grace, Richard W. Dewson, Jean-Noel Rebilly, Darren Bradshaw, Ben Carter, Andrew I. Cooper and Mathew J. Rosseinsky
Metal-organic frameworks (MOFs) are an emerging class of new nano-porous materials of considerable academic and industrial interest due to their potential applications in gas storagechiral separations and catalysis. MOFs are prepared from the self-assembly of metal ions (nodes) and organic ligands (spacers), where the structural topology of the resulting crystalline frameworks is driven by the co-ordination preferences of these nodes and spacers. MOFs offer opportunities not available to more cl
|A new exposure system for the in vitro detection of GHz field effects on neuronal networks|
Philipp J. Koester, Jan Sakowski, Werner Baumann, Hans-Walter Glocka, Jan Gimsa
Different ideas exist about possible targets for biological effects of electromagnetic fields (EMF). One of the favourite systems are the membranes of nerve cells, e.g. in the central nervous system. Our aim is to clarify whether EMF exposure may induce athermal effects. In the experiments, direct electrophysiological in vitro measurements are conducted on neuronal networks exposed to EMF, i.e. possible changes in the action potential patterns produced by the networks are detected. The technique
|Microwave-Assisted Rapid Access to Bio-active Heterocycles |
Vivek Polshettiwar and Rajender S. Varma
Environmentally benign protocols have been developed for the synthesis of various pharmaceutically active heterocycles namely 1,3,4-oxadiazoles, 1,3,4-thiadiazoles, 1,3-dioxanes, pyrazoles, hydrazones and 3,4-dihydropyrimidin-2(1H)-ones, which proceed under the influence of microwave irradiation and using eco-friendly conditions. These greener protocols were catalyzed efficiently by solid supported Nafion®NR50, phosphorus pentasulfide on alumina under solvent-free conditions.
|New Accessories for High Throughput and Combinatorial Approach in a Microwave Batch Reactor|
Alexander Stadler, Thomas Karner, Matthias Treu
A unique sealable well-plate system is introduced allowing screening reactions in a 8x6 well format with operation limits of 200°C and 20 bar and a reaction volume of 0.3 mL per well. An appropriate turntable enables to proceed up to 4 of these SiC well plates in one run resulting in 192 parallel reactions at a time. Reaction control is achieved by sensing the IR temperature of the plate surface.
|Microwave Accelerated Heterogeneous Catalysis – Flow-Through Reactor Concept and Application|
T. Glasnov, K. Mennecke, R. Cecillia, U. Kunz, A. Kirschning and C.O. Kappe,
Flow-through processes in organic synthesis become more important as an enabling technology for a cost effective and convenient method. This requires appropriate reactors with functionalities for organic reactions. In this project noble metal-loaded polymer/carrier reactors able to be operated in a microwave field were investigated. By application of a microwave field metal sites are heated whereas the polymer/carrier material remains transparent to irradiation.
|Phase Tranformation of Sodium Carbonate to Monohydrate|
A. Shaikh, A.D. Salman, S. Mcnamara, G, Littlewood and M.J. Hounslow
Sodium carbonate is the most widely used chemical compound in the world. The 50% of this used in glass industry is in the form of dense sodium carbonate. The process of transformation of sodium carbonate to sodium carbonate monohydrate is the key step in the production of dense sodium carbonate. In this present work systematic experiments were conducted by using online in-situ measurement techniques. It is shown that the kinetics of phase transformation process is highly temperature dependant.
|Synthesis of 4,5-dihydroisoxazoles from N-nitroso-4,5 dihydropyrazoles under Microwave Irradiation|
Kostikov R.R., Stepakov A.V., Galkin I.A and Molchanov A.P.
4,5-Dihydroisoxazoles have been used as key intermediates in the synthesis of a bioactive molecules and are found in pharmaceutical agents such as glycoprotein IIb/IIIa (GPIIb/IIIa) inhibitors and human leukocyte elastase inhibitors. In the present work 4,5-dihydroisoxazoles have been prepared by thermal removal of nitrogen from N-nitroso-4,5-dihydropyrazoles under microwave irradiation.
|The Effect of Microwave Irradiation Towards Carbodiimide-Mediated Esterifications on Solid Phase|
Alexander Stadler and Oliver Kappe
A number of publications have reported the coupling of carboxylic acids to Merrifield resin via the cesium salt method and the esterification of Wang resin using carbodiimide either via the isourea method or the symmetrical anhydride method. Reaction times using conventional conditions have been reported to be rather long so we have investigated the effects of microwave irradiation towards both of these reactions using benzoic acid derivatives.