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Heteroaromatic Compounds (heteroaromatic + compound)
Selected AbstractsChemInform Abstract: Palladium-Catalyzed Reductive N-Heterocyclization of Alkenyl-Substituted Nitroarenes as a Viable Method for the Preparation of Bicyclic Pyrrolo-Fused Heteroaromatic Compounds.CHEMINFORM, Issue 28 2010Sobha P. Gorugantula 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: Synthesis of Condensed Heteroaromatic Compounds by Palladium-Catalyzed Oxidative Coupling of Heteroarene Carboxylic Acids with Alkynes.CHEMINFORM, Issue 45 2009Mana Yamashita 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] Rhenium-Catalyzed Amidation of Heteroaromatic Compounds via C,H Bond Activation.CHEMINFORM, Issue 50 2007Yoichiro Kuninobu 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] ChemInform Abstract: Structural Chemistry of Polycyclic Heteroaromatic Compounds.CHEMINFORM, Issue 4 2002Part 12. 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: Catalytic, Highly Enantioselective Friedel,Crafts Reactions of Aromatic and Heteroaromatic Compounds to Trifluoropyruvate.CHEMINFORM, Issue 27 2001A Simple Approach for the Formation of Optically Active Aromatic, Heteroaromatic Hydroxy Trifluoromethyl Esters. 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] Palladium-Catalysed Amination of Electron-Deficient or Relatively Electron-Rich Benzo[b]thienyl Bromides , Preliminary Studies of Antimicrobial Activity and SARsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 17 2004Maria-João R. P. Queiroz Abstract Several diarylamines in the benzo[b]thiophene series were prepared in good to high yields by palladium-catalysed amination of ethyl 3-bromobenzo[b]thiophene-2-carboxylate with anilines and 5-aminoindole in the presence of Pd(OAc)2, BINAP and Cs2CO3 in toluene. The presence of the ester group at the 2-position of the benzo[b]thiophene moiety increases the yields and lowers the heating times relative to the reactions performed with 3-bromobenzo[b]thiophene. When aminopyridines were used instead of anilines, the ligand and the solvent need to be changed to XANTHPHOS and dioxane in the amination reaction. With 2-aminopyridine a one-pot C,N coupling and intramolecular cyclization involving the nitrogen atom of the pyridine ring occurred, with loss of ethanol, giving an interesting fluorescent tetracyclic heteroaromatic compound. The antimicrobial activity, the minimal inhibitory concentrations (MICs) and the structure-activity relationships (SARs) were evaluated. A selectivity with low MICs was observed against Bacillus Cereus, and good results were also obtained against Candida albicans. The acids obtained by hydrolysis of the ester group, as non-proteinogenic ,,,-unsaturated ,-amino acids, can be incorporated into peptide chains to induce conformational constraints. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Synthesis of polyfunctionally substituted heteroaromatic compounds via benzotriazolyl chalcones with antimicrobial and antifungal activitiesJOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 3 2004Fatima Al-Omran The utility of both 3-(1-benzotriazolyl) chalcone derivatives 3a-c and 2-(1-benzotriazolyl)-1,4-pentadien-3-one (18) in the synthesis of some new 2-(1H)-pyridone, pyridine, pyrazole and isoxazole derivatives is reported. Antimicrobial and antifungal screening of some selected examples from the synthesized products were carried out. The structure of the newly synthesized compounds was elucidated by elemental analysis, ir, 1H and 13C nmr investigations. [source] Asymmetric Hydrogenation with Water/Silane as the Hydrogen SourceCHEMISTRY - A EUROPEAN JOURNAL, Issue 4 2010Da-Wei Wang Dr. Water as a hydride source: A new pathway to form metal,hydride bonds has been developed through the reaction of easily available metal,silyl compounds with water. This method has been successfully applied to asymmetric hydrogenation of heteroaromatic compounds with up to 93,%,ee under mild autoclave-free conditions (see scheme). [source] Pd0 -Mediated Rapid Coupling between Methyl Iodide and Heteroarylstannanes: An Efficient and General Method for the Incorporation of a Positron-Emitting 11C Radionuclide into Heteroaromatic Frameworks,CHEMISTRY - A EUROPEAN JOURNAL, Issue 45 2009Masaaki Suzuki Prof. Abstract The Pd0 -mediated rapid trapping of methyl iodide with an excess amount of a heteroaryl-substituted tributylstannane has been investigated with the aim of incorporating a short-lived 11C-labelled methyl group into the heteroaromatic carbon frameworks of important organic compounds, such as drugs with various heteroaromatic structures, in order to execute a positron emission tomography (PET) study of vital systems. The reaction was first performed by using our previously developed CH3I/stannane/[Pd2(dba)3]/P(o -CH3C6H4)3/CuCl/K2CO3 (1:40:0.5:2:2:2) system in DMF at 60,°C for 5,min (conditions A), however, the reaction gave low yields for various heteroaromatic compounds. Increasing the amount of phosphine ligand (conditions B) led to a significant improvement in the yield, but the conditions were still not suitable for a range of basic heteroaromatic structures. Use of the CuBr/CsF system (conditions C) also provided a result similar to that obtained under conditions B with an increased amount of the phosphine. Thus, pyridine and related heteroaromatic compounds remained less reactive substrates. The problem was overcome by replacing the DMF solvent with N -methyl-2-pyrolidinone (NMP). The reaction in NMP at 60,100,°C for 5,min using a CH3I/stannane/[Pd2(dba)3]/P(o -CH3C6H4)3/CuBr/CsF (1:40:0.5:16:2:5) combination (conditions D) gave the methylated products in yields of more than 80,% (based on the reaction of CH3I) for all of the heteroaromatic compounds listed in this study. Thus, the combined use of NMP and an increased amount of phosphine is important for promoting the reaction efficiently. The use of this general approach to rapid methylation has been well demonstrated by the synthesis of the PET tracers 2- and 3-[11C]methylpyridines by using [Pd2(dba)3]/P(o -CH3C6H4)3/CuBr/CsF (1:16:2:5) in NMP at 60,°C for 5,min, which gives the desired products in HPLC analytical yields of 88 and 91,%, respectively. [source] Unlocking the Chemotherapeutic Potential of ,-Aminovinyl Ketones and Related CompoundsCHEMMEDCHEM, Issue 7 2009Hatem Abstract The role of ,-aminovinyl ketones as synthetic intermediates has been well categorised, but recent developments have shown an interesting array of applications and new chemotherapeutic potential, both in the preparation of biologically active heterocycles and as pharmacophores in their own right. Medicinal chemists are accustomed to using the products of Knoevenagel-type condensations as auxiliaries for the synthesis of N-containing heteroaromatic compounds. One such example of these chemical building blocks are ,-aminovinyl ketones,valuable synthetic intermediates that have been used in the preparation of pyridines, pyrimidines, pyrazoles, and many other heterocyclic motifs. This review highlights their recent use in the synthesis of biologically active targets as part of drug discovery programmes and in natural product synthesis. However, it is becoming increasingly evident that the enaminone motif may serve as a therapeutic pharmacophore in its own right. This review highlights the range of biological responses that ,-aminovinyl ketones elicit, including as antitumour, antibacterial, and anticonvulsant agents. Thus, with a broad spectrum of biological properties and as versatile chemical intermediates, it is clear that ,-aminovinyl ketones offer great potential in the search for new chemotherapeutic agents. [source] | ||||||||||