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Olefination Reaction (olefination + reaction)
Selected AbstractsChemInform Abstract: One-Pot Synthesis of Stilbenes from Alcohols Through a Wittig-Type Olefination Reaction Promoted by Nickel Nanoparticles.CHEMINFORM, Issue 44 2009Francisco Alonso 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] Desymmetrization of Diols by a Tandem Oxidation/Wittig Olefination Reaction.CHEMINFORM, Issue 41 2006David J. Phillips 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, please click on HTML or PDF. [source] Additions of Lithiated Alkoxyallenes to Phthalimide: A New Synthesis of Pyrroloisoindolones and an Unusual Olefination Reaction.CHEMINFORM, Issue 35 2006Silvia Kaden 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, please click on HTML or PDF. [source] Methylsulfonyl and Hydroxyl Substituents Induce Z-Stereocontrol in the McMurry Olefination Reaction.CHEMINFORM, Issue 47 2004Md. Jashim Uddin Abstract For Abstract see ChemInform Abstract in Full Text. [source] New Synthetic Approach to ,-Chlorocinnamates: First Example of Synthesis of Functionally Substituted Alkenes Using Catalytic Olefination Reaction.CHEMINFORM, Issue 28 2004Valentine G. Nenajdenko Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: A Facile Synthesis of Ring-Fused Alkylidenecyclopropanes by Olefination Reaction of Bicyclo[n.1.0]alkanone N,O-Hemiacetals with Wittig Reagents.CHEMINFORM, Issue 1 2002Morshed Alam Chowdhury Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 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] ChemInform Abstract: In situ Generation of Ylides for Tandem Oxidation,Olefination Reactions of Unactivated Diols.CHEMINFORM, Issue 30 2008David J. Phillips 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] 3,5-Bis(trifluoromethyl)phenyl Sulfones in the Julia,Kocienski Olefination , Application to the Synthesis of Tri- and Tetrasubstituted OlefinsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 20 2006Diego A. Alonso Abstract 3,5-Bis(trifluoromethyl)phenyl (BTFP) sulfones 8a,d are successfully employed in the modified Julia olefination reaction with carbonyl compounds employing phosphazene base P4- tBu at room temp. in THF, affording tri- and tetrasubstituted olefins in good yields. The Julia,Kocienski olefination between primary alkyl BTFP sulfones 8a,b and aromatic and aliphatic ketones affords the corresponding trisubstituted alkenes in good yields and low stereoselectivities. On the other hand, higher yields and stereoselectivities are obtained in the synthesis of trisubstituted olefins through the other approach, the coupling of secondary alkyl BTFP sulfones 8c,d with aliphatic, aromatic and ,,,-unsaturated aldehydes. For the first time, tetrasubstituted olefins are synthesized by means of the Julia,Kocienski protocol when the isopropyl BTFP sulfone 8c reacts with aliphatic and aromatic ketones, employing P4- tBu as base at THF reflux. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] A Novel Approach to 2-Chloro-2-fluorostyrenesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 2 2003Valentine G. Nenajdenko Abstract A new general catalytic olefination reaction (COR) of aromatic and heteroaromatic aldehydes and ketones was applied to synthesise 2-chloro-2-fluorostyrenes. The two-stage procedure includes the transformation of carbonyl compounds into hydrazones followed by treatment with CFCl3 mediated by copper catalysis. Trichlorofluoromethane was used as a chlorofluoromethylene transfer reagent. The reaction proceeds stereoselectively and the target alkenes were obtained in high yield. A proposed mechanism for the reaction is discussed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source] Organocatalytic Enantioselective Synthesis of Highly Functionalized Polysubstituted PyrrolidinesCHEMISTRY - A EUROPEAN JOURNAL, Issue 30 2008Nerea Ruiz Abstract The organocatalytic conjugate addition of different aldehydes to ,-nitroacrolein dimethyl acetal, generating the corresponding highly functionalized nitroaldehydes in high yields and with high stereoselectivities, has been studied in detail. These transformations have been achieved by using both readily available starting materials in a 1:1 ratio as well as commercially available catalysts at a 10,mol,% catalyst loading. Furthermore, a very short and efficient protocol has been devised for the preparation of highly enantioenriched pyrrolidines containing two or three contiguous stereocenters starting from the obtained Michael adducts. 3,4-Disubstituted pyrrolidines have been obtained in a single step by Zn-mediated chemoselective reduction of the nitro group followed by intramolecular reductive amination, and trisubstituted homoproline derivatives have been prepared by means of an olefination reaction and a cascade process involving chemoselective reduction of the nitro group followed by a fully diastereoselective intramolecular aza- Michael reaction. Se ha estudiado detalladamente la reacción de adición conjugada organocatalítica enantioselectiva de distintos aldehídos con el dimetil acetal de ,-nitroacroleina, obteniéndose los aductos correspondientes con excelente rendimiento y diastereo- y enantioselectividad. Esta transformación se lleva a cabo empleando cantidades equimolares de aldehído y nitroalqueno así como aminas secundarias quirales disponibles comercialmente como catalizadores en cantidad de 10,% molar. Además, se ha puesto a punto un protocolo sencillo y eficaz para la síntesis de pirrolidinas enantioenriquecidas conteniendo dos o tres estereocentros contíguos partiendo de los aductos Michael obtenidos. Así, se han preparado pirrolidinas 3,4-disustituidas desde sus precursores nitroaldehídicos a través de un proceso en cascada consistente en la reducción quemoselectiva del grupo nitro seguido de una reacción de aminación reductora intramolecular. Del mismo modo, partiendo de los mismos precursores, se han preparado derivados de homoprolina con tres centros estereogénicos mediante una reacción de Wittig seguida de un proceso en cascada de reducción/reacción aza-Michael intramolecular, cursando esta última con total diastereoselectividad. [source] | ||||||||||