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Arylation Reaction (arylation + reaction)
Selected AbstractsChemInform Abstract: Anodic Oxidation of Catechols in the Presence of ,-Oxoketene N,N-Acetals with a Tetrahydropyrimidine Ring: Selective ,-Arylation Reaction.CHEMINFORM, Issue 39 2010Cheng-Chu Zeng Abstract Electrochemical oxidation of catechols (II) generates the corresponding benzoquinones which subsequently react with ,-oxoketene N,N-acetals (I) to give the ,-arylation products (III). [source] ChemInform Abstract: Synthesis of Annulated 2H-Indazoles and 1,2,3- and 1,2,4-Triazoles via a One-Pot Palladium-Catalyzed Alkylation/Direct Arylation Reaction.CHEMINFORM, Issue 15 2009Benoit Laleu 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] A Route to Annulated Indoles via a Palladium-Catalyzed Tandem Alkylation/Direct Arylation Reaction.CHEMINFORM, Issue 5 2006Cyril Bressy Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: Synthesis of 6,8,9-Tri- and 2,6,8,9-Tetrasubstituted Purines by a Combination of the Suzuki Cross-Coupling, N-Arylation, and Direct C,H Arylation Reactions.CHEMINFORM, Issue 15 2009Igor Cerna 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] Synthesis of Mono- and Bis-Arylated 3,4-(Ethylenedioxythiophenes) via Direct Palladium-Catalyzed Arylation Reactions.CHEMINFORM, Issue 17 2007Arasambattu K. Mohanakrishnan 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] Synthesis of 5,5,-Diarylated 2,2,-Bithiophenes via Palladium-Catalyzed Arylation Reactions.CHEMINFORM, Issue 47 2004Aya Yokooji Abstract For Abstract see ChemInform Abstract in Full Text. [source] 2-Substituted Benzo[b]furans from (E)-1,2-Dichlorovinyl Ethers and Organoboron Reagents: Scope and Mechanistic Investigations into the One-Pot Suzuki Coupling/Direct Arylation,EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 29 2010Laina M. Geary Abstract 2-Substituted benzo[b]furans can easily be assembled from simple phenols, boronic acids or other organoboron reagents, and trichloroethylene. The overall process requires only two synthetic steps, with the key step being a one-pot sequential Suzuki cross-coupling/direct arylation reaction. The method tolerates many useful functional groups and does not require the installation of any other activating functionality. The modular nature of the process permits the rapid synthesis of many analogues using essentially the same chemistry, of particular value in drug development. Results of kinetic isotope effect studies and investigations into the regioselectivity of the process indicate that the direct arylation step most likely does not involve an electrophilic palladation. The most likely mechanism lies somewhere on the continuum between a C,H bond metathesis and an assisted palladation or concerted metallation-deprotonation pathway. [source] Synthesis of Benzomorphan Analogues by Intramolecular Buchwald,Hartwig CyclizationEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 2 2007Anton S. Khartulyari Abstract A new strategy toward the important class of benzomorphans is described. The key bond formation is based on an intramolecular Buchwald,Hartwig enolate arylation reaction. Thus, alkylation of piperidones with ortho -bromobenzyl bromides provides the necessary substrates. In the presence of a palladium catalyst, a sterically hindered phosphane ligand, and a base, carbon,carbon bond formation to tricyclic benzomorphan derivatives takes place. After removal of the N -protecting group, derivatization reactions are possible. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Remarkable Electronic Effect on the Diastereoselectivity of the Heck Reaction of Methyl Cinnamate with Arenediazonium Salts: Formal Total Synthesis of (±)-Indatraline and (±)-SertralineADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2009Julio Cezar Pastre Abstract An efficient and stereoselective protocol for the preparation of ,,,-disubstituted acrylates in good to high yields by means of a Heck,Matsuda arylation was accomplished. The method employs a base- and ligand-free Heck arylation reaction of methyl cinnamate using both electron-deficient and electron-rich arenediazonium salts as electrophiles. The Heck reaction displays a remarkable electronic dependence regarding the diastereoselectivity of the arylation process, which correlates with the electronic nature of the arenediazonium salts employed. A rationale for the observed diastereoselectivity is presented. The overall methodology provides a convenient route to 3-arylindanones and 4-aryltetralones allowing the concise formal total syntheses of the therapeutically important psychoactive compounds (±)-indatraline and (±)-sertraline. [source] Stereoselective synthesis of conformationally constrained tropane analogues: 6-Chloro-2,5-diazatetracyclo[8.5.0.02,13.04,9]pentadeca-4,6,8-triene-11-one and 6-chloro-2,7-diazatetracyclo-[8.5.0.02,13.04,9]pentadeca-4,6,8-triene-11-oneJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 4 2004Jie Cheng Two conformationally constrained tropane derivatives were prepared as rigid nicotinic acetylcholine receptor ligands. A palladium catalyzed intramolecular ,-arylation reaction was employed to generate the tricyclic compounds in good yields from N -(bromo-chloropyridylmethyl)-8-azabicyclo[3.2.1]octan-3-ones. [source] Understanding Sulfone Behavior in Palladium-Catalyzed Domino Reactions with Aryl IodidesCHEMISTRY - A EUROPEAN JOURNAL, Issue 17 2006Inés Alonso Dr. Abstract Unlike traditionally used acyclic 1,2-disubstituted alkenes, the reaction of ,,,-unsaturated phenyl sulfones with aryl iodides under Heck reaction conditions takes place mainly by means of a four-component domino process, involving one unit of the alkene and three units of the aryl iodide, affording substituted 9-phenylsulfonyl-9,10-dihydrophenanthrenes. We report here the results of a computational study on the mechanism of this domino arylation reaction. Based on these results we can explain why vinyl sulfones, unlike other electron-deficient alkenes such as enones, preferentially follow this domino pathway instead of the usual Heck pathway. The key step is a CH activation process in which a five-membered palladacycle is formed. The greater ability of vinyl sulfones, relative to enones, to reach the transition state that leads to the formation of the initial palladacycle makes the difference. Al contrario que los alquenos acíclicos 1,2-disustituidos tradicionalmente utilizados, la reacción de fenil sulfonas ,,, -insaturadas con yoduros de arilo bajo condiciones de reacción de Heck tiene lugar mayoritariamente a través de un proceso dominó de cuatro componentes, en el que participan una unidad de alqueno y tres unidades de yoduro de arilo, dando lugar a 9-fenilsulfonil-9,10-dihidrofenantrenos sustituidos. Aquí se presentan los resultados de un estudio computacional sobre el mecanismo de esta reacción de arilación dominó. De acuerdo con estos resultados se puede explicar por qué en el caso de las vinil sulfonas este camino de reacción predomina sobre la reacción de Heck, al contrario que en el caso de otros alquenos pobres en electrones como las enonas. La etapa clave es un proceso de activación CH en el que se forma un paladaciclo de cinco miembros. La mayor capacidad de las vinil sulfonas en comparación con las enonas para alcanzar el estado de transición que conduce al paladaciclo es la causa fundamental de este comportamiento diferencial. [source] Copper-Catalyzed N -Arylation of Hindered Substrates Under Mild ConditionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 6 2009Michael Abstract A mild, efficient method utilizing a copper-diamine catalyst at room temperature is reported for the coupling of hindered imidazoles with unsubstituted, ortho- substituted, and bis- ortho -substituted boronic acids in good to excellent yields. Aryl halides do not reaction under these conditions permitting sequential N -arylation reactions. [source] JS-K, a novel non-ionic diazeniumdiolate derivative, inhibits Hep 3B hepatoma cell growth and induces c-Jun phosphorylation via multiple MAP kinase pathwaysJOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2003Zhenggang Ren JS-K, a non-ionic diazeniumdiolate derivative, is capable of arylating nucleophiles and spontaneously generating nitric oxide (NO) at physiological pH. This recently synthesized low molecular weight compound is shown here to be an inhibitor of cell growth with concomitant activation of mitogen-activated protein kinase (MAPK) members ERK, JNK, and p38 and their downstream effectors c-Jun and AP-1. Inhibitors of these MAPK pathways abrogated the growth inhibitory actions of JS-K. In addition to the well-described actions of JNK as a kinase for c-Jun, we show that c-Jun is also an ERK target. Furthermore, JS-K generated NO in culture and NO inhibitors antagonized both MAPK induction and the growth inhibitory effects of JS-K. These results suggest two possible mechanisms for the mediation of JS-K growth inhibitory actions, namely NO-induction of MAPK pathway constituents as well as possible arylation reactions. The data support the idea that prolonged MAPK activation by JS-K action is important in mediating its growth-inhibitory actions. JS-K thus represents a promising platform for novel growth inhibitory analog synthesis. J. Cell. Physiol. 197: 426,434, 2003© 2003 Wiley-Liss, Inc. [source] | ||||||||||