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Direct Arylation (direct + arylation)
Selected Abstracts2-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] Palladium-Catalyzed C2 or C5 Direct Arylation of 3-Formylthiophene Derivatives with Aryl BromidesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 4 2010Jia Jia Dong Abstract The system Pd(OAc)2/dppb was found to be an efficient catalyst precursor for the direct arylation of 3-formylthiophene derivatives. When using 3-formylthiophene, the 2-arylated thiophenes were obtained with regioselectivities of 76,86,%, whereas the arylation of 3-formylthiophene diethyl acetal gave the 5-arylated thiophenes with regioselectivities of 64,88,%. These reactions were performed by using only 0.1 mol-% of the catalyst. Moreover, this procedure has been found to be tolerant to a variety of functional groups on the aryl bromide such as formyl, propionyl, benzoyl, nitrile, or nitro. [source] Evaluation of Electron-Deficient Phosphine Ligands for Direct Arylation of HeterocyclesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2010Olivier René Abstract New electron-deficient biarylphosphine ligands were studied and proved to be efficient for the direct arylation of heteroarenes with aryl iodides. The ability of a more electron-deficient palladium centre to accelerate the arylation of heterocycles that remained unreactive with aryl iodides in the past has been validated and these heteroarenes can now be smoothly reacted in the presence of a new electrophilic catalyst. Experimental evidence suggests a viable concerted metalation,deprotonation pathway for the CH bond cleavage step with an electron-deficient palladium centre. [source] Palladium-Catalysed Direct Arylation of Heteroaromatics Bearing Unprotected Hydroxyalkyl Functions using Aryl BromidesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 4 2010Julien Roger Abstract Heteroaromatics bearing unprotected hydroxyalkyl functions can be arylated using aryl or heteroaryl bromides, via palladium-catalysed carbon-hydrogen bond activation/arylation. Good yields were generally obtained using 0.01,0.5,mol% of the air-stable palladium acetate complex as the catalyst. The nature of the base was found to be crucial for the selectivity of this reaction. Potassium acetate led to the direct arylation products whereas caesium carbonate led to the formation of the ether. This procedure is certainly more atom-economic than other methods for the preparation of such compounds, as no protection/deprotection sequence of the hydroxyalkyl function and no preparation of an organometallic derivative is required. [source] Regioselective C-2 or C-5 Direct Arylation of Pyrroles with Aryl Bromides using a Ligand-Free Palladium CatalystADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2009Julien Roger Abstract A simple and atom-economical procedure for the regioselective C-2 or C-5 arylation of pyrroles via a CH bond activation is reported. Only 0.5,0.01 mol% of commercially available and air-stable ligand-free palladium(II) acetate [Pd(OAc)2] was employed as the catalyst. The presence of electron-withdrawing substituents such as formyl, acetyl or ester at the C-2 position of the pyrrole is tolerated. This environmentally attractive procedure has also been found to be tolerant to a very wide variety of functional groups on the aryl bromides such as formyl, acetyl, propionyl, ester, nitrile, nitro, fluoro, methoxy, amino or trifluoromethyl. [source] A Versatile Palladium/Triphosphane System for Direct Arylation of Heteroarenes with Chloroarenes at Low Catalyst Loading,ANGEWANDTE CHEMIE, Issue 37 2010David Roy Ein luftbeständiger Palladiumkatalysator mit dreizähnigem Phosphanligand aryliert elektronenreiche wie elektronenarme mehrfach substituierte Furane (X=O), Thiophene (X=S) und Pyrrole (X=NR5) sowie Thiazole direkt unter C-H-Aktivierung mit Chlorarenen (siehe Schema; DMAc=N,N -Dimethylacetamid, TBAB=Tetra- n -butylammoniumbromid). [source] Iron-Catalyzed Direct Arylation of Unactivated Arenes with Aryl Halides,ANGEWANDTE CHEMIE, Issue 11 2010Wei Liu Eiserne Hilfe: Eine Vielzahl an Arylhalogeniden wurde mit nichtaktivierten Arenen in mäßigen bis guten Ausbeuten zu Biarylverbindungen umgesetzt. Die Reaktionen wurden bei relativ niedriger Temperatur in Gegenwart katalytischer Mengen FeCl3 mit DMEDA als Ligand und LiHMDS als Base durchgeführt (siehe Schema; DMEDA=N,N' -Dimethylethan-1,2-diamin, HDMS=Hexamethyldisilazanid). [source] ChemInform Abstract: Iron-Catalyzed Direct Arylation Through an Aryl Radical Transfer Pathway.CHEMINFORM, Issue 29 2010Frederic Vallee 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: Palladium-Catalyzed Direct Arylation of 4-Chromanones: Selective Synthesis of Racemic Isoflavanones and 3,3-Diaryl-4-chromanones.CHEMINFORM, Issue 27 2010Fabio Bellina 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: Direct Arylation of 2H-Indazoles on Water.CHEMINFORM, Issue 23 2010Stephen A. Ohnmacht 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: Palladium-Catalyzed Direct Arylation-Based Domino Synthesis of Annulated N-Heterocycles Using Alkenyl or (Hetero)Aryl 1,2-Dihalides.CHEMINFORM, Issue 9 2010Lutz Ackermann 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: Copper-Mediated Direct Arylation of 1,3,4-Oxadiazoles and 1,2,4-Triazoles with Aryl Iodides.CHEMINFORM, Issue 1 2010Tsuyoshi Kawano 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: Direct Arylation of Azine N-Oxides with Aryl Triflates.CHEMINFORM, Issue 44 2009Derek J. Schipper 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] ChemInform Abstract: Palladium-Catalyzed Direct Arylation of 4-Hydroxycoumarins with Arylboronic Acids via C,OH Bond Activation.CHEMINFORM, Issue 33 2009Yong Luo 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] ChemInform Abstract: Copper(I)-Catalyzed Direct Arylation of 1,4-Disubstituted 1,2,3-Triazoles with Aryl Iodides.CHEMINFORM, Issue 28 2009Shin-ichi Fukuzawa 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] ChemInform Abstract: Ligand-Free Palladium-Catalyzed Direct Arylation of Thiazoles at Low Catalyst Loadings.CHEMINFORM, Issue 24 2009Julien Roger 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] ChemInform Abstract: Pd-Catalyzed Direct Arylation of Tautomerizable Heterocycles with Aryl Boronic Acids via C,OH Bond Activation Using Phosphonium Salts.CHEMINFORM, Issue 1 2009Fu-An Kang 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] ChemInform Abstract: Ligandless Microwave-Assisted Pd/Cu-Catalyzed Direct Arylation of Oxazoles.CHEMINFORM, Issue 32 2008Francois Besselievre 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] ChemInform Abstract: Aryl Triflates: Useful Coupling Partners for the Direct Arylation of Heteroaryl Derivatives via Pd-Catalyzed C,H Activation,Functionalization.CHEMINFORM, Issue 24 2008Julien Roger 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] ChemInform Abstract: Direct Arylation of Thiophenes via Palladium-Catalyzed C,H Functionalization at Low Catalyst Loadings.CHEMINFORM, Issue 14 2008Ahmed Battace 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] ChemInform Abstract: Synthesis of Alkylated Benzo[2,1-b:3,4-b,]dithiophenes (III) by Annulative Coupling and Their Direct Arylation under Palladium Catalysis.CHEMINFORM, Issue 13 2008Hiroyuki Watanabe 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] Palladium-Catalyzed Direct Arylation of Furans via C,H Functionalization at Low Catalyst Loadings.CHEMINFORM, Issue 23 2007Ahmed Battace 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] A Novel, High-Yielding Synthesis of meso-Substituted Porphyrins via the Direct Arylation of Porphine.CHEMINFORM, Issue 11 2003Dong-Fang Shi Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: A Facile Synthesis of 2-Arylindenes by Pd-Catalyzed Direct Arylation of Indene with Aryl Iodides.CHEMINFORM, Issue 33 2002Ilya E. Nifant'ev 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] A Versatile Catalyst for Intermolecular Direct Arylation of Indoles with Benzoic Acids as Arylating ReagentsCHEMISTRY - A EUROPEAN JOURNAL, Issue 20 2010Jun Zhou Coupled together: With a versatile catalyst system (Pd(TFA)2/Ag2CO3/propionic acid) both electron-rich and -deficient benzoic acids serve as arylating reagents for the direct functionalization of a wide rage of indoles by a combination of decarboxylation and CH bond activation. Depending on the nature of the benzoic acids, the reaction occurs selectively at either the C2- or C3-position of indoles, which may arise from two different catalytic pathways (see scheme; TFA=trifluoroacetate). [source] RuCl3,x,H2O-Catalyzed Direct Arylation of Arenes with Aryl Chlorides in the Presence of TriphenylphosphineCHEMISTRY - A EUROPEAN JOURNAL, Issue 3 2010Ning Luo A simple, efficient, and economically attractive catalytic system has been developed for the direct arylation of arenes with aryl chlorides with the RuCl3,xH2O/PPh3/Na2CO3/N -methyl-2-pyrrolidone system (see scheme). A remarkable effect of the nature of the base was observed, with Na2CO3 giving the best results. [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] Palladium-Catalyzed C2 or C5 Direct Arylation of 3-Formylthiophene Derivatives with Aryl BromidesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 4 2010Jia Jia Dong Abstract The system Pd(OAc)2/dppb was found to be an efficient catalyst precursor for the direct arylation of 3-formylthiophene derivatives. When using 3-formylthiophene, the 2-arylated thiophenes were obtained with regioselectivities of 76,86,%, whereas the arylation of 3-formylthiophene diethyl acetal gave the 5-arylated thiophenes with regioselectivities of 64,88,%. These reactions were performed by using only 0.1 mol-% of the catalyst. Moreover, this procedure has been found to be tolerant to a variety of functional groups on the aryl bromide such as formyl, propionyl, benzoyl, nitrile, or nitro. [source] Evaluation of Electron-Deficient Phosphine Ligands for Direct Arylation of HeterocyclesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2010Olivier René Abstract New electron-deficient biarylphosphine ligands were studied and proved to be efficient for the direct arylation of heteroarenes with aryl iodides. The ability of a more electron-deficient palladium centre to accelerate the arylation of heterocycles that remained unreactive with aryl iodides in the past has been validated and these heteroarenes can now be smoothly reacted in the presence of a new electrophilic catalyst. Experimental evidence suggests a viable concerted metalation,deprotonation pathway for the CH bond cleavage step with an electron-deficient palladium centre. [source] RuCl3,x,H2O-Catalyzed Direct Arylation of Arenes with Aryl Chlorides in the Presence of TriphenylphosphineCHEMISTRY - A EUROPEAN JOURNAL, Issue 3 2010Ning Luo A simple, efficient, and economically attractive catalytic system has been developed for the direct arylation of arenes with aryl chlorides with the RuCl3,xH2O/PPh3/Na2CO3/N -methyl-2-pyrrolidone system (see scheme). A remarkable effect of the nature of the base was observed, with Na2CO3 giving the best results. [source] | ||||||||||||||||||||||