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Various Aryl (various + aryl)
Selected AbstractsNovel Building Blocks: 1-Aryl-2-chloro-1-ethoxyethenes , Preparations and Transformations,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 3 2007Mitsuhiro Yoshimatsu Abstract We described here a simple method for the preparation of 1-aryl-2-chloro-1-ethoxyethenes 2a,u, which are prodrugs for Alzheimer's disease, by the reaction of dichloroacetaldehyde diethyl acetal with various aryl and alkenyllithium compounds in high yields. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Material Solubility-Photovoltaic Performance Relationship in the Design of Novel Fullerene Derivatives for Bulk Heterojunction Solar CellsADVANCED FUNCTIONAL MATERIALS, Issue 5 2009Pavel A. Troshin Abstract The preparation of 27 different derivatives of C60 and C70 fullerenes possessing various aryl (heteroaryl) and/or alkyl groups that are appended to the fullerene cage via a cyclopropane moiety and their use in bulk heterojunction polymer solar cells is reported. It is shown that even slight variations in the molecular structure of a compound can cause a significant change in its physical properties, in particular its solubility in organic solvents. Furthermore, the solubility of a fullerene derivative strongly affects the morphology of its composite with poly(3-hexylthiophene), which is commonly used as active material in bulk heterojunction organic solar cells. As a consequence, the solar cell parameters strongly depend on the structure and the properties of the fullerene-based material. The power conversion efficiencies for solar cells comprising these fullerene derivatives range from negligibly low (0.02%) to considerably high (4.1%) values. The analysis of extensive sets of experimental data reveals a general dependence of all solar cell parameters on the solubility of the fullerene derivative used as acceptor component in the photoactive layer of an organic solar cell. It is concluded that the best material combinations are those where donor and acceptor components are of similar and sufficiently high solubility in the solvent used for the deposition of the active layer. [source] A Convenient High Activity Catalyst for the Sonogashira Coupling of Aryl BromidesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2005Axel Köllhofer Abstract A mixture of Na2PdCl4, CuI and (t -Bu)3PH+BF4, (molar ratio 4,:,3,:,8) dispersed in H2N(i -Pr)2+Br, can be used as a "single source" precatalyst for the Sonogashira coupling of aryl bromides with various aryl- and alkylacetylenes in HN(i -Pr)2 solvent. Arylacetylenes require just 0.005,mol,% of Pd catalyst at 80,°C, with TOFs ranging between 3,200 and 10,000,h,1. [source] Dppc+PF6,,PdCl2,[bmim][PF6],a copper-free recyclable catalytic system for Sonogashira coupling reactionAPPLIED ORGANOMETALLIC CHEMISTRY, Issue 5 2007Jintao Guan Abstract An air-stable, copper-free and highly efficient Dppc+PF6,,PdCl2,[bmim][PF6] catalytic system has been developed for the Sonogashira coupling reaction of aryl iodides with various aryl- and alkylacetylenes. The catalytic system allows for facile separation and can be recycled at least eight times with minimal loss of activity. Copyright © 2007 John Wiley & Sons, Ltd. [source] Facile and Efficient Reduction of Ketones in the Presence of Zinc Catalysts Modified by Phenol LigandsCHEMISTRY - AN ASIAN JOURNAL, Issue 9 2010Stephan Enthaler Dr. Abstract In the present study, the zinc-catalyzed hydrosilylation of various ketones to give their corresponding alcohols has been examined in detail. Diethyl zinc that can be modified by easily accessible phenol ligands allows the efficient reduction of various aryl and alkyl ketones. By using a practical in situ catalyst, excellent turnover frequencies up to 1000,h,1 and a broad functional group tolerance were achieved. Im Rahmen dieser Arbeit wird die Zink-katalysierte Hydrosilylierung von Ketonen zu den entsprechenden Silylethern mit anschließender Hydrolyse zu deren Alkoholen vorgestellt. Wobei exzellente Ausbeuten und Umsätze durch die Modifikation des katalytisch eingesetzten Diethylzink mit Phenolen erreicht werden konnten. Nach genauer Untersuchung verschiedenster Reaktionsparameter konnten turnover frequencies (TOF) von ca. 1000,h,1 erzielt werden. Die hervorragenden Eigenschaften des Katalysatorsystems konnte weiterhin in der Hydrosilylierung verschiedenster Ketone erfolgreich gezeigt werden. Zum besseren Verständnis der Reaktion wurden verschiedene mechanistische Experimente durchgeführt. [source] | ||||||||||