Bicyclo

Distribution by Scientific Domains
Distribution within Chemistry


Selected Abstracts


Thermal Behavior of Free-Base and Core-Modified Bicyclo[2.2.2]octadiene-Fused Porphyrins

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 1 2008
Hidemitsu Uno
Abstract Multistep thermal fragmentation of quadruply bicyclo[2.2.2]octadiene-fused porphyrins giving tetrabenzoporphyrins was examined in detail. After the first extrusion of an ethylene molecule from the porphyrin derivative, the opposite bicyclo[2.2.2]octadiene moiety preferentially underwent the second retro-Diels,Alder reaction to give an opp -dibenzoporphyrin derivative rather than an adj -dibenzoporphyrin derivative. These two benzoporphyrin derivatives then decomposed to give a tribenzoporphyrin derivative in similar rates. The temperature regions of these fragmentations could not be distinguished by thermogravimetric analysis. In contrast, the third and the fourth fragmentations obviously occurred stepwise. There was a temperature region where the tribenzoporphyrin derivative preferentially existed. In the case of the 21,23-dithiaporphyrin derivative, opp -21,23-dithiadibenzoporphyrin, possessing benzo moieties fused at the pyrrole parts of the core-modified porphyrin chromophore was predominantly formed during the fragmentation. In the case of the 21-thiaporphyrin derivative, an ethylene molecule was extruded selectively from the bicyclo[2.2.2]octadiene moiety adjacent to the thiophene part to give 21-thiabenzo[q]porphyrin and then 21-thiabenzo[g,q]porphyrin derivatives. In these cases, the last ethylene extrusion also occurred very slowly. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]


Four New Lignans with a Bicyclo[3.3.1]nonadienemethanol Skeleton from Cunninghamia lanceolata

HELVETICA CHIMICA ACTA, Issue 10 2009
Ching-Kuo Lee
Abstract Four unique bicyclo[3.3.1]nonadienemethanol lignans, designated lanceolatanins A (1), B (2), C (3), and D (4), along with one previously known compound, isolariciresinol (5), were isolated from the MeOH extracts of the heartwood of Cunninghamia lanceolata. Their structures were elucidated by application of various spectroscopic methods, including 1D- and 2D-NMR techniques, to their acetylated derivatives 1a, 2a, 3a, and 4a. Their possible biosynthetic formations are also discussed. [source]


Gold-Catalyzed Synthesis of Bicyclo[3.2.0]heptenes via a Formal [3+2]/[2+2]-Annulation of Allylsilane with 4-Methoxybut-2-yn-1-ols

ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2010
Chun-Yao Yang
Abstract This work reports the novel gold-catalyzed [3+2]/[2+2]-annulation of allylsilane with 4-methoxybut-2-yn-1-ols that yields highly strained bicyclo[3.2.0]heptene products efficiently and stereoselectively. [source]


NMR Characterization of Carbazole-Substituted Norbornene Comonomer 9-(Bicyclo[2.2.1.]hept-5-en-2-ylmethyl)-9H -carbazole (BHMCZ) and Poly(ethylene- co -BHMCZ) Copolymer

MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 3 2003
Ilpo Mustonen
Abstract Carbazole-substituted norbornene comonomer 9-(bicyclo[2.2.1.]hept-5-en-2-ylmethyl)-9H -carbazole (BHMCZ) can be copolymerized with ethylene using the [Ph2C(Ind)(Cp)ZrCl2] catalyst and methylaluminoxane (MAO) cocatalyst system. The microstructures of BHMCZ comonomer and of ethylene,BHMCZ copolymer containing 4.6 mol-% BHMCZ units in the chain were characterized by one-dimensional 13C DEPT and two-dimensional homonuclear 1H- 1H COSY and heteronuclear 1H- 13C HXCO NMR spectroscopy. The BHMCZ comonomer appears as endo and exo stereoisomers, which were identified on the basis of chemical shifts, signal multiplicities, and coupling in the 2D NMR spectra. The NMR information on the BHMCZ isomers was used to assist in the determination of the chemical shifts and microstructure of ethylene,BHMCZ copolymer. The NMR analysis of ethylene,BHMCZ copolymer indicated that exo -BHMCZ polymerizes with ethylene slightly more readily than does endo -BHMCZ under the polymerization conditions employed. Isolated segments of exo(2)- exo(5)- exo(6) and endo(2)- exo(5)- exo(6) ethylene-BHMCZ copolymer showing carbon atom numbering. [source]


Synthesis and properties of BCDA-based polyimide,clay nanocomposites

POLYMER INTERNATIONAL, Issue 6 2007
P Santhana Gopala Krishnan
Abstract Bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BCDA)-based polyimide,clay nanocomposites were prepared from their precursor, namely polyamic acid, by a solution-casting method. The organoclay was prepared by treating sodium montmorillonite (Kunipia F) clay with dodecyltrimethylammonium bromide at 80 °C. Polyamic acid solutions containing various weight percentages of organoclay were prepared from 4,4,-(4,4,-isopropylidenediphenyl-1,1,-diyldioxy)-dianiline and BCDA in N -methyl-2-pyrrolidone containing dispersed particles of organoclay at 20 °C. These solutions were cast on a glass plate using a Doctor's blade and then heated subsequently to obtain nanocomposite films. The nanocomposites were characterized using Fourier transform infrared spectroscopy, differential scanning calorimetry, thermal mechanical analysis, dynamic mechanical analysis, polarizing microscopy, scanning electron microscopy, transmission electron microscopy, wide-angle X-ray diffraction (WAXD) and thermogravimetric analysis. The glass transition temperature of the nanocomposites was found to be higher than that of pristine polymer. The coefficient of thermal expansion of the nanocomposites decreased with increasing organoclay content. WAXD studies indicated that the extent of silicate layer separation in the nanocomposite films depended upon the organoclay content. Tensile strength and modulus of the nanocomposite containing 1% organoclay were significantly higher when compared to pristine polymer and other nanocomposites. The thermal stability of the nanocomposites was found to be higher than that of pristine polymer in air and nitrogen atmosphere. Copyright © 2007 Society of Chemical Industry [source]


Rhodium-Catalyzed Asymmetric Conjugate Addition of Organoboronic Acids to Nitroalkenes Using Chiral Bicyclo[3.3.0] Diene Ligands,

ANGEWANDTE CHEMIE, Issue 33 2010
Zhi-Qian Wang
Nichts geht über Diene: In der Titelreaktion mit anspruchsvollen Nitroalkenen ohne ,-Substituenten als Substraten und unter ArB(OH)2/KHF2 -Bedingungen waren chirale Bicyclo[3.3.0]-Diene die besten Liganden. Np = Naphthyl. [source]


Gold-Catalyzed Tandem Cyclization of Dienol Silyl Ethers for the Preparation of Bicyclo[4.3.0]nonane Derivatives,

ANGEWANDTE CHEMIE, Issue 25 2010
Hiroyuki Kusama Dr.
Über den Fünfring zum Sechsring: Eine goldkatalysierte geminale Carbofunktionalisierung von 3-Siloxy-1,3-dien-8-inen führte über die Ringerweiterung eines bicyclischen Carbenkomplexes glatt und stereoselektiv zu Bicyclo[4.3.0]nonanen. Das Produkt unterschied sich in seiner Konfiguration von dem Produkt einer thermischen Diels-Alder-Addition. [source]


Chemoenzymatic Synthesis and Application of Bicyclo[2.2.2]octadiene Ligands: Increased Efficiency in Rhodium-Catalyzed Asymmetric Conjugate Additions by Electronic Tuning,

ANGEWANDTE CHEMIE, Issue 15 2010
Yunfei Luo
Liganden nach Wunsch: Eine Serie von bicyclischen 1,4-Dimethyl[2.2.2]dien-Liganden mit flexibler Substitution in der Brücke ist durch Lipase-katalysierte Racematspaltung mit anschließender sechsstufiger Reaktionssequenz zugänglich. Die Methylgruppen am Brückenkopf führen zu einer erhöhten Reaktionseffizienz, wodurch in der Titelreaktion weniger Arylboronsäure nötig ist. [source]


Rhodium(I)-Catalyzed Intramolecular [5+2],Cycloaddition Reactions of Alkynes and Allenylcyclopropanes: Construction of Bicyclo[5.4.0]undecatrienes and Bicyclo[5.5.0]dodecatrienes,

ANGEWANDTE CHEMIE, Issue 12 2010
Fuyuhiko Inagaki Dr.
Von Allenen zu Bicyclen: Bei der [{RhCl(CO)2}2]- oder [{RhCl(CO)dppp}2]-katalysierten intramolekularen [5+2]-Cycloaddition von Alkin-Allenylcyclopropanen entstehen unter milden Bedingungen die Bicyclo[5.4.0]undecatrien- oder die größeren Bicyclo[5.5.0]dodecatrien-Gerüste (dppp=1,3-Bis(diphenylphosphanyl)propan). [source]


Sequential Platinum-Catalyzed Cycloisomerization and Cope Rearrangement of Dienynes,

ANGEWANDTE CHEMIE, Issue 2 2010
Sun Young Kim
Mit Enin geht,s rund: Die Titelreaktionen ergeben bicyclische Systeme wie Bicyclo[3.2.2]nonadiene 1 oder tetrahydrierte kondensierte Ringe 2 in hohen Ausbeuten (siehe Schema; Z=NTs, O, CH2). [source]


Acid-Catalyzed Intramolecular [2+2] Cycloaddition of Ene-allenones: Facile Access to Bicyclo[n.2.0] Frameworks,

ANGEWANDTE CHEMIE, Issue 39 2009
Jun-Feng Zhao
Zwei plus zwei macht zwei Ringe: Eine hoch effiziente säurekatalysierte intramolekulare [2+2]-Cycloaddition von Enallenonen (siehe Schema; Tf: Trifluormethansulfonyl) ergibt unter milden Bedingungen gespannte Bicyclo[n.2.0]-Gerüste mit benachbarten quartären und tertiären Stereozentren in ausgezeichneten Ausbeuten und Chemo-, Regio- und Diastereoselektivitäten. [source]


ChemInform Abstract: Chemoenzymatic Synthesis and Application of Bicyclo[2.2.2]octadiene Ligands: Increased Efficiency in Rhodium-Catalyzed Asymmetric Conjugate Additions by Electronic Tuning.

CHEMINFORM, Issue 34 2010
Yunfei Luo
Abstract A new series of 1,4-disubstituted 2,5-diaryl bicyclo[2.2.2]octadienes are prepared. [source]


ChemInform Abstract: Thermal Behavior of Bicyclo[2.2.2]octadiene-Installed Precursors for 2H-Anthra[2,3-c]pyrroles and Anthra[2,3-c]thiophene.

CHEMINFORM, Issue 34 2010
Hiroki Uoyama
Abstract 4,11-Ethano-4,11-dihydro-2H-anthra[2,3-c]pyrroles (IV) and the corresponding thiophene (VI) are prepared, and their thermogravimetric behavior is studied. [source]


ChemInform Abstract: PtCl2 -Catalyzed Cycloisomerization of 1,6-Enynes for the Synthesis of Substituted Bicyclo[3.1.0]hexanes.

CHEMINFORM, Issue 15 2010
Liu Ye
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: Au(I)-Catalyzed Cycloisomerization Reaction of Amide- or Ester-Tethered 1,6-Enynes to Bicyclo[3.2.0]hept-6-en-2-ones.

CHEMINFORM, Issue 11 2010
Young Tak Lee
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: Phosphine-Catalyzed [4 + 3] Annulation for the Synthesis of Highly Functionalized Bicyclo[3.2.2]nonadienes.

CHEMINFORM, Issue 5 2010
Suqing Zheng
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 Synthetic Strategy for Polyfunctionalized Bicyclo[3.3.1]nonanes Based on a Tandem Three-Component [3 + 2] Cycloaddition of ,-Cinnamoyl Ketene-S,S-acetals with Oxalyl Chloride.

CHEMINFORM, Issue 52 2009
Yu-Long Zhao
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: Asymmetric Organocatalytic Domino Michael/Aldol Reactions: Enantioselective Synthesis of Chiral Cycloheptanones, Tetrahydrochromenones, and Polyfunctionalized Bicyclo[3.2.1]octanes.

CHEMINFORM, Issue 35 2009
Magnus Rueping
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: A Formal [3 + 2] Cycloaddition for the Synthesis of Bicyclo[3.2.1]octanes.

CHEMINFORM, Issue 26 2009
Crina M. Orac
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: Regioselectivities in Alkyne Activation: Synthesis of 2-(Bicyclo[3.1.0]hexan-1-yl)furan Derivatives by Au-Catalyzed Cyclization and Cyclopropanation.

CHEMINFORM, Issue 14 2009
Chang Ho Oh
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: Asymmetric Synthesis of Bicyclo[4.3.1]decadienes and Bicyclo[3.3.2]decadienes via [6 + 3] Trimethylenemethane Cycloaddition with Tropones.

CHEMINFORM, Issue 12 2009
Barry M. Trost
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: Gold(I)-Catalyzed [4 + 2] Anellation/Nucleophilic Addition Sequence: Stereoselective Synthesis of Functionalized Bicyclo[4.3.0]nonenes.

CHEMINFORM, Issue 11 2009
Sebastian Boehringer
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: A Semi-Pinacol Rearrangement Approach to Bicyclo[3.2.1]octan-2-ones and Bicyclo[3.2.1]octan-3-ones.

CHEMINFORM, Issue 1 2009
Sejin Lee
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: Stereoselective Synthesis of Substituted Bicyclo[3.1.1]heptanes.

CHEMINFORM, Issue 1 2009
Part 2.
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: A Synthesis of Bicyclo[n.1.0]alkanes Having tert-Butyl Carboxylate or Acetamide Moiety via the Intramolecular 1,3-CH Insertion of Magnesium Carbenoids.

CHEMINFORM, Issue 47 2008
Shingo Ogata
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: Combining Multi-Catalysis and Multicomponent Systems for the Development of One-Pot Asymmetric Reactions: Stereoselective Synthesis of Highly Functionalized Bicyclo[4.4.0]decane-1,6-diones.

CHEMINFORM, Issue 47 2008
Dhevalapally B. Ramachary
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: Enantioselective Synthesis of Bicyclo[2.2.2]octenones Using a Copper-Mediated Oxidative Dearomatization/[4 + 2] Dimerization Cascade.

CHEMINFORM, Issue 29 2008
Suwei Dong
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: Enantioselective, NHC-Catalyzed Bicyclo-,-lactam Formation via Direct Annulations of Enals and Unsaturated N-Sulfonyl Ketimines.

CHEMINFORM, Issue 22 2008
Ming He
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: A Direct Synthesis of Alkenyl Alkylidene Bicyclo[3.1.0]hexane Derivatives (III) via Ruthenium(II)-Catalyzed Bicyclization of Allenynes.

CHEMINFORM, Issue 22 2008
Chloe Vovard-Le Bray
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 Diels,Alder Reaction of 2H-Pyran-2-ones with Maleimides Towards Fused Bicyclo[2.2.2]octenes.

CHEMINFORM, Issue 20 2008
Kristof Kranjc
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]