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Intramolecular Cyclization (intramolecular + cyclization)
Terms modified by Intramolecular Cyclization Selected AbstractsA Mechanistic Rationale for the Mode Selectivity in the Intramolecular Cyclization of Ethylene-Tethered Iminoketenimines: [2+2] versus [4+2] Stepwise CycloadditionsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 12 2004Mateo Alajarín Abstract A stepwise mechanism, via a zwitterionic intermediate, has been established by ab initio and DFT calculations for the intramolecular cyclization of N -(3-azabut-3-enyl)ketenimine into its corresponding [2+2] cycloadduct. The control of the mode selectivity ([2+2] versus [4+2] cycloaddition) in the intramolecular cyclization of C -vinyl- N -(iminoethylene)ketenimines, which favors the [4+2] cycloadducts, also has been rationalized by comparing the energies calculated for both reaction pathways; the results have been confirmed by a quantitative kinetic analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Base- and Copper-Catalyzed Intramolecular Cyclization for the Direct Synthesis of DihydrofuransADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 7 2010Yong-Fei Chen Abstract A simple and convenient synthetic approach to dihydrofurans has been developed from the cyclization of 2-propynyl-1,3-dicarbonyl compounds catalyzed by potassium tert -butoxide, copper(II) trifluoromethanesulfonate and triphenylphosphine using methanol/dichloromethane as the solvent under very mild conditions. Moreover, dihydrofurans could be easily transformed into the corresponding furans in the presence of trifluoroacetic acid. [source] Phase-Transfer-Catalyzed Intramolecular Cyclization of ortho -Alkynyl Phenyl Ether Derivatives for Synthesis of 2,3-Disubstituted Benzo[b]furansADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 2-3 2010Jie Hu Abstract A variety of substituted benzo[b]furans are readily prepared in good to excellent yields under the mild reaction conditions from o -(1-alkynylphenoxy)-1-phenylethanone under phase-transfer catalysis (PTC). This methodology accommodates simple experimental operations, inexpensive and environmentally benign catalysts, metal catalyst-free conditions, facile reagents and the possibility to conduct large-scale preparations. The development of carbon-carbon bond formation processes via an overall structural isomerization represents the most atom-economical approach. [source] Silver-Catalyzed Intramolecular Cyclization of o -(1-Alkynyl)benzamides: Efficient Synthesis of (1H)-Isochromen-1-iminesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2009Guannan Liu Abstract An efficient avenue for the facile and atom-economic synthesis of (1H)-isochromen-1-imines has been developed, and a broad spectrum of substrates can participate in the process effectively to produce the desired products in good yields. Significantly, this is the first report of the synthesis of (1H)-isochromen-1-imines that involves a silver(I)-catalyzed, regiocontrolled intramolecular addition of the carbonyl group of the amide moiety towards an alkyne. [source] Efficient Access to Extended Yagupolskii,Umemoto-Type Reagents: Triflic Acid Catalyzed Intramolecular Cyclization of ortho -Ethynylaryltrifluoromethylsulfanes,ANGEWANDTE CHEMIE, Issue 3 2010Andrej Matsnev Chef im Ring: Die S -(Trifluormethyl)benzo[b]thiophenium-Salze 1, Analoga für Yagupolskii-Umemoto-Reagentien, wurden durch eine neuartige Trifluormethansulfonsäure-katalysierte intramolekulare Cyclisierung aus ortho -Ethinylaryltrifluormethylsulfanen 2 synthetisiert. 1,j erwies sich als besonders nützlich in der elektrophilen Trifluormethylierung von ,-Ketoestern und Dicyanalkylidenen. [source] ChemInform Abstract: Cationic Gold(I)-Catalyzed Intramolecular Cyclization of ,-Hydroxyalkynones into 3(2H)-Furanones.CHEMINFORM, Issue 27 2010Masahiro Egi 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: Dess,Martin Periodinane Mediated Intramolecular Cyclization of Phenolic Azomethines: A Solution-Phase Strategy Toward Benzoxazoles and Benzothiazoles.CHEMINFORM, Issue 22 2010D. Subhas Bose 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: Cationic Gold(I)-Mediated Intramolecular Cyclization of 3-Alkyne-1,2-diols and 1-Amino-3-alkyn-2-ols: A Practical Route to Furans and Pyrroles.CHEMINFORM, Issue 12 2010Masahiro Egi 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: Silver-Catalyzed Intramolecular Cyclization of o-(1-Alkynyl)benzamides: Efficient Synthesis of (1H)-Isochromen-1-imines.CHEMINFORM, Issue 11 2010Guannan Liu 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: Dichotomous Control of E/Z-Geometry in Intramolecular Cyclization of o-Alkynylbenzamide Derivatives Catalyzed by Organic Superbase P4-tBu in the Presence/Absence of Water.CHEMINFORM, Issue 9 2010Chikashi Kanazawa 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: A Novel Carbanion-Olefin Intramolecular Cyclization: Synthesis of Substituted 2-Aroyl-3,4-dihydro-2H-benzopyrans from Salicylaldehydes.CHEMINFORM, Issue 4 2010Liang-Yeu Chen 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 Novel 3-Bromo-2H-chromene Derivatives: Palladium-Mediated Intramolecular Cyclization of Aryl Propargyl Ethers.CHEMINFORM, Issue 52 2009Gurunathan Savitha 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 Benzoxazoles via Intramolecular Cyclization of ortho-Halobenzanilides Using Copper Fluorapatite Catalyst.CHEMINFORM, Issue 48 2009M. Lakshmi Kantam 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: Efficient Three-Component One-Pot Synthesis of Fully Substituted Pyridin-2(1H)-ones via Tandem Knoevenagel Condensation,Ring-Opening of Cyclopropane,Intramolecular Cyclization.CHEMINFORM, Issue 42 2009Fushun Liang 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: Efficient Horner,Wadsworth,Emmons Intramolecular Cyclization of a N-Substituted Phthalimide Promoted by KF-Alumina: A General Tool for the Synthesis of Functionalized Isoindolinones.CHEMINFORM, Issue 39 2009Vittorio Pace 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 Novel 3-(Aryl)benzothieno[2,3-c]pyran-1-ones from Sonogashira Products and Intramolecular Cyclization: Antitumoral Activity Evaluation.CHEMINFORM, Issue 34 2009Maria-Joao R. P. Queiroz 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: Unprecedented SnCl2×2H2O-Mediated Intramolecular Cyclization of Nitroarenes via C,N Bond Formation: A New Entry to the Synthesis of Cryptotackieine (XII) and Related Skeletons.CHEMINFORM, Issue 11 2009Sunil Sharma 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 3-Alkyl-1H-quinolin-2-ones via Palladium-Catalyzed Intramolecular Cyclization of Benzyl Halides and ,,,-Unsaturated Amides.CHEMINFORM, Issue 44 2008Zhangqin Liu 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: Microwave-Assisted Intramolecular Cyclization of Electron-Rich Heterocycle Derivatives by a Palladium-Catalyzed Coupling Reaction.CHEMINFORM, Issue 22 2008Egle M. Beccalli 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: 2-(Prenyloxymethyl)benzoyl (POMB) Groups: A New Temporary Protecting Group Removable by Intramolecular Cyclization.CHEMINFORM, Issue 6 2008Jean-Michel Vatele 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] Unexpected Formation of 4-Hydroxy-6-nitroindoles in the Intramolecular Cyclization of O-(3-Amino-5-nitrophenyl)ketoximes.CHEMINFORM, Issue 37 2007Sergei S. Vorob'ev 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] One-Pot Synthesis of Substituted Indole N-Oxides: TiCl4 -Mediated Baylis,Hillman Reaction of ,-Oxo Cyclic Ketene-S,S-acetal with o-Nitrobenzaldehydes and Subsequent Intramolecular Cyclization.CHEMINFORM, Issue 36 2006Wei Pan 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] Free Radical Synthesis of Benzofused Tricyclic ,-Lactams by Intramolecular Cyclization of 2-Azetidinone-Tethered Haloarenes.CHEMINFORM, Issue 30 2005Benito Alcaide Abstract For Abstract see ChemInform Abstract in Full Text. [source] Intramolecular Cyclization of 5-Aryl-3-arylamino-4-benzoyl-1H-3-pyrrolin-2-ones to Pyrrolo[3,4-b]quinolines.CHEMINFORM, Issue 28 2005V. L. Gein No abstract is available for this article. [source] A New Approach to 2,2-Disubstituted Chromenes and Tetrahydroquinolines Through Intramolecular Cyclization of Chiral 3,4-Epoxy Alcohols.CHEMINFORM, Issue 34 2004Jean-Yves Goujon Abstract For Abstract see ChemInform Abstract in Full Text. [source] The Synthesis of Phosphaisocoumarins by Cu(I)-Catalyzed Intramolecular Cyclization of o-Ethynylphenylphosphonic Acid Monoesters.CHEMINFORM, Issue 15 2004Ai-Yun Peng No abstract is available for this article. [source] Regiospecific Synthesis of 3-Alkyl-2-aryl-4-trifluoromethylbenzo[h]quinolines by Intramolecular Cyclization of N-(2-Alkyl-1-aryl-3-oxo-4,4,4-trifluorobut-1-en-1-yl)-1-naphthylamines.CHEMINFORM, Issue 39 2002Helio Gauze Bonacorso Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: Efficient Strategy for the Iterative Synthesis of trans-Fused Polycyclic Ether via SmI2 -Induced Reductive Intramolecular Cyclization.CHEMINFORM, Issue 30 2002Nobuyuki Hori 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] Synthesis and Molecular Structure of New Unsaturated Analogues of Nucleotides Containing Six-Membered RingsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 3 2005Valery K. Brel Abstract The reaction of 1-(chloromethyl)-3-(diethoxyphosphonyl)allenes 15 and 16 with purine and pyrimidine bases in the presence of cesium carbonate afforded new acyclic analogs of nucleotides containing a 1,2-alkadienic skeleton (17,24). Intramolecular cyclization of the alkoxides tethered to the allenyl moiety yielded dihydropyrans 33,38 and dihydrofurans 39 and 40. Dealkylation of the dihydropyrans led to the corresponding phosphonic acids. The molecular structures of new nucleotide analogs 33 and 36 were determined by single-crystal X-ray analyses. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Synthesis of Well-Defined Figure-of-Eight-Shaped Polymers by a Combination of ATRP and Click ChemistryMACROMOLECULAR RAPID COMMUNICATIONS, Issue 20 2008Gang-Yin Shi Abstract Well-defined figure-of-eight-shaped (8-shaped) polystyrene (PS) with controlled molecular weight and narrow polydispersities has been prepared by the combination of atom transfer radical polymerization (ATRP) and click chemistry. The synthesis involves two steps: 1) Preparation of a linear tetrafunctional PS with two azido groups, one at each end of the polymer chain, and two acetylene groups at the middle of the chain. 2) Intramolecular cyclization of the linear tetrafunctional PS at a very low concentration by a click reaction to produce the 8-shaped polystyrenes. The resulting intermediates and the target polymers were characterized by 1H NMR and FT-IR spectroscopy, and gel permeation chromatography. The glass transition temperatures (Tgs) were determined by differential scanning calorimetry and it was found that the decrease in chain mobility by cyclization resulted in higher Tgs for 8-shaped polystyrenes as compared to their corresponding precursors. [source] | |||||||||||||||||||||||||||||||