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Ring System (ring + system)

Distribution by Scientific Domains
Chemistry93%
4 Other Domains7%
Distribution within Chemistry
Organic Chemistry61%
Crystallography12%
General & Introductory Chemistry6%
11 Other Subdomains15%

Kinds of Ring System

  • aromatic ring system
    		•
  • heterocyclic ring system
    		•
  • new ring system
    		•

    Selected Abstracts

    ChemInform Abstract: Synthesis of a Novel Tricyclic 1,2,3,4,4a,5,6,10b-Octahydro-1,10-phenanthroline Ring System and CXCR4 Antagonists with Potent Activity Against HIV-1.

    CHEMINFORM, Issue 37 2010
    John G. Catalano
    Abstract Stereorandom and diastereoselective syntheses of novel title ring system are described. [source]

    ChemInform Abstract: Stereoselective Synthesis of cis- and trans-2,3-Disubstituted Tetrahydrofurans via Oxonium,Prins Cyclization: Access to the Cordigol Ring System.

    CHEMINFORM, Issue 29 2010
    Alan C. Spivey
    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 Facile Synthesis of Bispyrroloquinone and Bispyrroloiminoquinone Ring System of Marine Alkaloids.

    CHEMINFORM, Issue 39 2009
    Srinivasan Murugesan
    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: Pyrazolo[4,,3,:5,6]pyrano[2,3-b]quinoxalin-4(1H)-one: Synthesis and Characterization of a Novel Tetracyclic Ring System.

    CHEMINFORM, Issue 4 2008
    Gernot A. Eller
    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]

    Studies Toward the Total Synthesis of Nakiterpiosin: Construction of the CDE Ring System by a Transannular Diels,Alder Strategy.

    CHEMINFORM, Issue 46 2007
    Tomonori Ito
    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]

    Tributyltin Hydride Mediated Straightforward Synthesis of a New Isoxazolo-benzazulene Ring System.

    CHEMINFORM, Issue 1 2007
    Vijay Singh
    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]

    Reaction of Malonates with Camphoranile Synthesis of 4-Hydroxy-2-pyridones Attached to the Bornane Ring System.

    CHEMINFORM, Issue 1 2007
    Stanislav Kafka
    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]

    Penifulvin A: A Sesquiterpenoid-Derived Metabolite Containing a Novel Dioxa[5,5,5,6]fenestrane Ring System from a Fungicolous Isolate of Penicillium griseofulvum.

    CHEMINFORM, Issue 31 2006
    Sang Hee Shim
    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 and in vitro Antihepatitis B and C Virus Activities of Ring-Expanded ("Fat") Nucleobase Analogues Containing the Imidazo[4,5-e][1,3]diazepine-4,8-dione Ring System.

    CHEMINFORM, Issue 11 2006
    Peng Zhang
    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 4-Methyl Pyrrolo[2,3-b]xanthone, a Novel Ring System.

    CHEMINFORM, Issue 10 2006
    Samuel E. Watson
    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]

    Rh(I)-Catalyzed Allenic Pauson,Khand Reaction: First Construction of the Bicyclo[6.3.0]undecadienone Ring System.

    CHEMINFORM, Issue 7 2006
    Chisato Mukai
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access the actual ChemInform Abstract, please click on HTML or PDF. [source]

    A Convenient Synthesis of Quinolin-2(1H)-one Ring System as Precursor of Active Drugs.

    CHEMINFORM, Issue 28 2005
    Gamal Giuglio-Tonolo
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Syntheses of (-)-TAN-2483A, (-)-Massarilactone B, and the Fusidilactone B Ring System.

    CHEMINFORM, Issue 52 2004
    (.+-.)-Waol B (FD-212)., Revision of the Structures of, Syntheses of (.+-.)-Waol A (FD-211)
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Solution Phase Synthesis of Imidazo[1,2-b]pyrazol-2-one, an Interesting 5,5-Fused Heterocyclic Ring System.

    CHEMINFORM, Issue 17 2004
    Benjamin E. Blass
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Isolation and Structure of Providencin: A Highly Oxygenated Diterpene Possessing a Unique Bicyclo[12.2.0]hexadecane Ring System from the Sea Plume Pseudopterogorgia kallos.

    CHEMINFORM, Issue 45 2003
    Jeffrey Marrero
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Samarium(II) Iodide Mediated Radical/Polar Crossover Reactions of Cyclobutenes: An Efficient Approach to the BCD Ring System of the Penitrems.

    CHEMINFORM, Issue 25 2003
    Alexey Rivkin
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Stereoselective Synthesis of the Indolizinoindole Ring System.

    CHEMINFORM, Issue 23 2003
    Steven M. Allin
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Synthesis of 1-Azaspiroundecane Ring System via Thorpe,Ziegler Annulation of 2-Cyano-2-(4-cyano-tethered) Arylpiperidines.

    CHEMINFORM, Issue 39 2002
    Richard Malassene
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Synthesis of Two Novel Classes of Tetracycles Bearing Tetrahydro Ring System from Benzothiazole: 7,8,9,10-Tetrahydrothiazolo[5,4-a]acridine and 1,2,3,4-Tetrahydro-12H-benzothiazolo[2,3-b]quinazolin-12-one.

    CHEMINFORM, Issue 38 2002
    Maxime Robin
    No abstract is available for this article. [source]

    ChemInform Abstract: Large-Scale Synthesis of New Cyclazines, 5-Thia-1,8b-diazaacenaphthylene-3-carboxylic Acid Derivatives Having the Peripheral 12,-Electron Ring System.

    CHEMINFORM, Issue 26 2002
    Tomomi Ikemoto
    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 and in vitro Cytotoxic Evaluation of New Derivatives of Pyrido[1,2-a]benzimidazolic Ring System: The Pyrido[1,,2,:1,2]imidazo[4,5-h]quinazolines.

    CHEMINFORM, Issue 7 2002
    Marianne Dupuy
    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: Dibenzo[b,h][1,4,7]thiadiazonines: Examples of a Novel Ring System.

    CHEMINFORM, Issue 50 2001
    Alan R. Katritzky
    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 Sequence of Aldol Condensations and a Michael Addition Giving a Cyclohexenone Ring System.

    CHEMINFORM, Issue 26 2001
    Ulrich Kuhl
    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 Dynamic Features of (Chloro)zirconocene Cations Stabilised by Pendant (Diarylphosphanyl)alkyl and (Dimethylamino)alkyl Substituents at Their Cyclopentadienyl Ring Systems

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 8 2003
    Steve Döring
    Abstract Treatment of the substituted (diarylphosphanyl)methyl group-4 metallocene complexes [(C5H4,CR1R2,PAr2)2ZrCl2] (2: R1/R2 = CH3/CH3, H/CH3, H/aryl) with Li[B(C6F5)4] in dichloromethane solution results in chloride ligand abstraction (with LiCl precipitation) to yield the complexes [(C5H4,CR1R2,PAr2)2Zr,Cl+] (5), with both phosphanyl groups internally coordinated to the metal centre. Three possible diastereoisomers are observed in the case of 5c (R1 = H; R2 = CH3), while bulkier R2 substituents give higher selectivities. The thermally induced (reversible) cleavage of the Zr,phosphane linkage results in dynamic NMR behaviour. Gibbs activation energies of ,G,(298 K) = 14.8 ± 0.5 and 14.5 ± 0.5 kcal/mol were obtained for these intramolecular equilibration processes in the complexes trans - 5d (R1 = H; R2 = Ph) and trans - 5e (R1 = H; R2 = ferrocenyl), respectively. Treatment of the substituted (dimethylamino)methyl metallocene complexes [(C5H4,CR1R2,NMe2)2ZrCl2] (6a, 6b) with Li[B(C6F5)4] proceeds analogously to yield the cation systems [{C5H4,C(CH3)2,NMe2}2ZrCl+] (12a) and [{C5H4,CH(CH3),NMe2}2ZrCl+] (12b, three possible diastereoisomers). Both complexes have their pairs of amino groups coordinated to the metal centre. The complexes exhibit dynamic NMR spectra. Selective equilibration of the diastereotopic N(CH3)A(CH3)B resonances of complex 12a is observed [,G,(233 K) = 11.5 ± 0.2 kcal/mol], whereas the adjacent C(CH3)A(CH3)B methyl groups remain diastereotopic. The dynamic equilibration of the latter was observed at a markedly higher temperature [,G,(333 K) = 17.3 ± 0.2 kcal/mol]. Treatment of [{C5H4,C(CH3)2,NMe2}CpZrCl2] (10) with Li[B(C6F5)4] resulted in the formation of complex [{C5H4,C(CH3)2,NMe2}CpZr,Cl+] (11), which shows the internal ,N(CH3)A(CH)B equilibration proceeding with a markedly higher activation barrier [,G,(333 K) = 17.6 ± 0.2 kcal/mol] than in 12a, and a stereochemical memory effect indicative of solvent coordination to the metal centre of the resulting highly electrophilic chlorozirconocene cation intermediate. Complex 11 was characterised by an X-ray crystal structure analysis, which shows the internal Zr,amine coordination. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

    Nucleophilic Opening of Oxabicyclic Ring Systems,

    ANGEWANDTE CHEMIE, Issue 34 2009
    Corinna
    Mit Leichtigkeit gingen auch gesättigte [2.2.1]Oxabicyclo-Systeme 1 eine Lewis-Säure-vermittelte nucleophile Ringöffnung ein, die auf direktem Weg zu hoch funktionalisierten Perhydroindolen (n=1) oder Perhydrochinolinen (n=2) führt (siehe Schema). Sowohl Amin- als auch Amidsubstituenten kamen bei dieser effizienten und allgemeinen Umsetzung als Nucleophile zum Einsatz. [source]

    Novel Fused Pyrrole Heterocyclic Ring Systems as Structure Analogs of LE 300: Synthesis and Pharmacological Evaluation as Serotonin 5-HT2A, Dopamine and Histamine H1 Receptor Ligands

    ARCHIV DER PHARMAZIE, Issue 2 2010
    Sherif A. F. Rostom
    Abstract LE 300 represents a structurally novel type of antagonists acting preferentially at the dopamine D1/D5 receptors and the serotonin 5-HT2A receptor. This compound consists of a ten-membered central azecine ring fused to an indole ring on one side and a benzene moiety on the other side. To estimate the importance of the indole and / or phenyl moieties in this highly active benz-indolo-azecine, both rings were removed and replaced with a 1H -pyrrole counterpart. Accordingly, some new analogs of LE 300 namely, pyrrolo[2,3- g]indolizine, pyrrolo[3,2- a]quinolizine rings and their corresponding dimethylpyrrolo[2,3- d]azonine, and dimethylpyrrolo[2,3- d]azecine were synthesized to be evaluated for their activity at the 5-HT2A and dopamine D1, D2L, D4, D5 receptors in relation to LE 300. In addition, their activity at the H1 -histamine receptors was also determined. The results suggested that the rigid pyrrolo[2,3- g]indolizine 7 and pyrrolo[3,2- a]quinolizine 8 analogs lacked biological activity in the adopted three bioassays. However, their corresponding flexible pyrrolo[2,3- d]azonine 11 and pyrrolo[2,3- d]azecine 12 derivatives revealed weak partial agonistic activity and weak antagonistic potency at the serotonin 5-HT2A and histamine H1 receptors, respectively. Meanwhile, they showed no affinity to any of the four utilized dopamine receptors. Variation in ring size did not contribute to a significant influence on the three tested bioactivities. Removal of the hydrophobic moiety (phenyl ring) and replacement of the indole moiety with a 1H -pyrrole counterpart led to a dramatic alteration in the profile of activity of such azecine-type compounds. [source]

    Synthesis and Biological Evaluation of Some Polymethoxylated Fused Pyridine Ring Systems as Antitumor Agents

    ARCHIV DER PHARMAZIE, Issue 10 2009
    Sherif A. F. Rostom
    Abstract A series of 3,5- bis(arylidene)-4-piperidones like chalcone analogues carrying variety of methoxylated aryl groups, pyrazolo[4,3- c]pyridines, pyrido[4,3- d]pyrimidines, and pyrido[3,2- c]pyridines, carrying an arylidene moiety, and some pyrano[3,2- c]pyridines, like flavone and coumarin isosteres, were synthesized and screened for their in-vitro antitumor activity at the National Cancer Institute (NCI, USA). The tested compounds 7, 9, 10, 12, 13, 15, 17, and 19 exhibited a broad spectrum of antitumor activity. Compounds belonging to the pyrazolo[4,3- c]pyridine series proved to be more active than those of the pyrido[3,2- c]pyridine and pyrano[3,2- c]pyridine analogues, in which the monomethoxylated derivatives showed better antitumor activity when compared with their corresponding dimethoxylated congeners. Compound 7 is considered to be the most active member identified in this study with a broad spectrum of activity against 22 different tumor cell lines belonging to the nine subpanels employed, and a particular effectiveness against the breast cancer T-47D cell line (GI 54.7%). The pyrano[3,2- c]pyridine heterocyclic system 19 proved to be the most active antitumor agent among the six-membered fused pyridines, with variable activity against 18 different tumor cell lines, and special activity against the non-small cell lung cancer Hop-92 and ovarian cancer OVCAR-4 cell lines (GI values 63.9 and 48.5%, respectively). [source]

    ChemInform Abstract: Cascade Synthesis of New Tetracyclic Heteroaromatic Thieno[2,3-b]pyridine-Containing Ring Systems.

    CHEMINFORM, Issue 18 2010
    R. Alan Aitken
    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 New 4-Pyrrol-1-yl Benzoic Acid Hydrazide Analogues and Some Derived Oxadiazole, Triazole and Pyrrole Ring Systems: A Novel Class of Potential Antibacterial and Antitubercular Agents.

    CHEMINFORM, Issue 10 2009
    S. D. Joshi
    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 Indole-Based Ring Systems by Acid-Catalyzed Condensation from ,-Amino Aldehydes and L-Trp-OMe.

    CHEMINFORM, Issue 31 2008
    Paolo Grieco
    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]