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Metathesis

Distribution by Scientific Domains
Chemistry96%
Polymers and Materials Science3%
Distribution within Chemistry
Organic Chemistry77%
General & Introductory Chemistry17%
6 Other Subdomains6%

Kinds of Metathesis

  • Ring-Close metathesis
  • alkene metathesis
  • alkyne metathesis
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  • closing metathesis
  • cross metathesis
  • enyne metathesis
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  • olefin metathesis
  • ring closing metathesis
  • ring-closing metathesis
    		•

    Terms modified by Metathesis

  • metathesis catalyst
  • metathesis polymerization
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  • metathesis reaction
  • metathesis sequence
    		•

    Selected Abstracts

    Reactions of K2[Fe(CO)3(PPh3)]: Reductive Sb,Sb Coupling with Ph2SbCl To Form trans -[Fe(CO)3(PPh3)(Sb2Ph4)] and Salt Metathesis with Me3SbCl2 To Yield trans -[Fe(CO)3(PPh3)(SbMe3)]

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2005
    Ingo-Peter Lorenz
    Abstract In contrast to the ferrate K2[Fe(CO)4], the phosphane-substituted ferrate K2[Fe(CO)3(PPh3)] (1) reacts with the stibane derivative Ph2SbCl by metal-assisted reductive Sb,Sb coupling to give the distibane complex trans -[Fe(CO)3(PPh3)(Sb2Ph4)] (3). The distibane ligand in 3 is terminally ,1 -coordinated trans to the phosphane ligand. However, the stiborane derivative Me3SbCl2 reacts with 1 in a metathetical substitution reaction to form the monostibane complex trans -[Fe(CO)3(PPh3)(SbMe3)] (5). Both compounds have been characterized by spectroscopic (IR, NMR, MS), analytical (C, H) and X-ray diffraction analyses. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]

    Facile Synthesis of Selenium-Containing Bicyclic ,-Lactams through Enyne Metathesis

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 14 2010
    Deepali B. Bankar
    Abstract Novel selenium-containing bicyclic ,-lactams were obtained through stereoselective insertion of (but-3-enyl)seleno and propargylseleno moieties at the C(4) positions of azetidinones with subsequent ring-closing enyne metathesis. [source]

    Synthesis of Carbohydrate-Derived Enynes and Subsequent Metathesis to Yield Polyhydroxylated 1-Vinylcycloalkenes

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 12 2003
    Franck Dolhem
    Abstract In this paper, a new route toward polyhydroxylated 1-vinylcycloalkenes is presented. 1,6- and 1,7-enynes were synthesized in four steps from glyco-ynitols, which are readily available from monosaccharides. These compounds were then cyclized by ring-closing enyne metathesis to afford the title compounds. For example, we converted (2R,3S,4R)-1- O -tritylhept-6-yne-1,2,3,4-tetrol (1) to the corresponding 1,7-enyne 13 in 53% yield. The ring-closing metathesis of 1,7-enyne 13 with Grubbs catalyst, under Mori's conditions, produced the corresponding polyhydroxylated 1-vinylcyclohexene 19 in 72% yield. The conversion of several glyco-ynitols into polyhydroxylated 1-vinylcycloalkenes was carried out with satisfying yields. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

    Stereoselective Synthesis of Tetrahydrofuran Spiro- , -Lactams by Ru-Catalyzed Metathesis of 7-Oxabicyclo[2.2.1]heptenes

    HELVETICA CHIMICA ACTA, Issue 6 2005
    Aurelio
    A new method for the synthesis of spiro- , -lactams tethered to tetrahydrofuran rings is described. The procedure is based on Ru-catalyzed metathesis sequences with oxanorbornene precursors easily obtained by the Staudinger [2+2] cycloaddition of related imines. [source]

    Efficient Heterogeneous Dual Catalyst Systems for Alkane Metathesis

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1 2010
    Zheng Huang
    Abstract A fully heterogeneous and highly efficient dual catalyst system for alkane metathesis (AM) has been developed. The system is comprised of an alumina-supported iridium pincer catalyst for alkane dehydrogenation/olefin hydrogenation and a second heterogeneous olefin metathesis catalyst. The iridium catalysts bear basic functional groups on the aromatic backbone of the pincer ligand and are strongly adsorbed on Lewis acid sites on alumina. The heterogeneous systems exhibit higher lifetimes and productivities relative to the corresponding homogeneous systems as catalyst/catalyst interactions and bimolecular decomposition reactions are inhibited. Additionally, using a "two-pot" device, the supported Ir catalysts and metathesis catalysts can be physically separated and run at different temperatures. This system with isolated catalysts shows very high turnover numbers and is selective for the formation of high molecular weight alkanes. [source]

    Magnetic Nanoparticle Supported Second Generation Hoveyda,Grubbs Catalyst for Metathesis of Unsaturated Fatty Acid Esters

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2009
    Zhu Yinghuai
    Abstract The Hoveyda,Grubbs catalyst has been successfully immobilized on surface-modified magnetic nanoparticles with a loading amount of 0.28,mmol ruthenium/g (magnetic support). The supported catalysts were active for the self-metathesis of methyl oleate and macro-monomer in a quantitative conversion, respectively. In addition, the catalyst can be easily separated by using a magnet and reused several times with sustained activity. [source]

    New Indenylidene-Schiff Base-Ruthenium Complexes for Cross-Metathesis and Ring-Closing Metathesis

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 16 2009

    Abstract We here report on the stability and catalytic activity of new indenylidene-Schiff base-ruthenium complexes 3a,f through representative cross-metathesis (CM) and ring-closing metathesis (RCM) reactions. Excellent activity of the new complexes was found for the two selected RCM reactions; prominent conversion was obtained compared to the commercial Hoveyda,Grubbs catalyst 2. Moreover, excellent results were obtained for a standard CM reaction. Higher conversions were achieved with one of the indenylidene catalysts compared with Hoveyda,Grubbs catalyst. Unexpectedly, an isomerization reaction was observed during the CM reaction of allylbenzene. To the best of our knowledge, isomerization reactions in this model CM reaction in closed systems have never been described using first generation catalysts, including the Hoveyda,Grubbs catalyst. The first model CM reactions as well as the RCM reactions have been monitored using 1H,NMR. The course of the CM reaction of 3-phenylprop-1-ene (8) and cis -1,4-diacetoxybut-2-ene (9) was monitored by GC. The isomerization reaction was studied by means of GC-mass spectrometry and in situ IR spectroscopy. All catalysts were structurally characterized by means of 1H, 13C, and 31P,NMR spectroscopy. [source]

    Ferrocene Redox Controlled Reversible Immobilization of Ruthenium Carbene in Ionic Liquid: A Versatile Catalyst for Ring-Closing Metathesis

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2009
    Guiyan Liu
    Abstract A ferrocene-tagged ruthenium carbene 15 that can be reversibly immobilized in an ionic liquid (IL) via the controlled oxidation and reduction of a ferrocene tag was prepared. This offers a new strategy which uses redox chemistry to control immobilization and to recycle both the catalyst and the IL. In this experiment, 11 recycles were performed for the ring-closing metathesis (RCM) of a substrate using 16 as the catalyst in an ionic liquid (IL). More importantly, after the reaction was completed, the ruthenium catalyst was easily separated from the supporting IL by just adding decamethylferrocene (DMFc) to reduce the cationic ferrocene and then extracting it with benzene. Thus, this recycle system offers an easy way to recycle both the ruthenium catalyst and the IL. [source]

    Metathesis in Pure Water Mediated by Supramolecular Additives

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 3 2009
    Thomas Brendgen
    Abstract Supramolecular, water-soluble additives based on calix[n]arenes exhibit a beneficial influence on the ring-closing and cross metathesis of non-polar substrates in pure aqueous medium using standard Grubbs-II and Hoveyda-II catalysts. The catalytic activity observed in water is virtually the same as that in pure methanol. Quantitative yields of metathesis product can be achieved under mild aerobic conditions in/on water by (micro)solubilization of both the catalyst and starting materials by the macrocycles. [source]

    Simple Ruthenium Precatalyst for the Synthesis of Stilbene Derivatives and Ring-Closing Metathesis in the Presence of Styrene Initiators

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 4-5 2007
    Cheikh Lo
    Abstract The ruthenium complex RuCl2(p -cymene)(IMes) was found to be an efficient precatalyst, with styrene as an initiating species, for the alkene metathesis of various styrenes into symmetrical and unsymmetrical stilbene derivatives and for the ring-closing metathesis reaction of a sterically hindered olefin leading to a tetrasubstituted cycloolefin. [source]

    Recent Advances in the Syntheses and Applications of Molybdenum and Tungsten Alkylidene and Alkylidyne Catalysts for the Metathesis of Alkenes and Alkynes

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 1-2 2007
    Richard
    Abstract The last several years have produced some key advances in the area of alkene and alkyne metathesis by high oxidation state alkylidene and alkylidyne complexes along with new applications in organic and polymer chemistry. In this review we cover some of these developments and applications. The first part of this review concerns developments in catalyst synthesis and new catalysts. The second part concerns notable applications in organic and polymer chemistry. We discuss only high oxidation state alkylidene and alkylidyne chemistry of relevance to alkene or alkyne metathesis reactions and favor studies in the homogeneous phase. [source]

    Terminal Alkyne Metathesis: A Further Step Towards Selectivity

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 15 2006
    Olivier Coutelier
    Abstract Terminal alkyne metathesis has been improved by addition of quinuclidine as an external ligand to the (t- BuO)3WCBu- t carbyne complex, giving a yield of 80,% during hept-1-yne metathesis. Extension of this system to the co-metathesis of terminal and disubstituted alkynes affords the expected cross-reaction products. [source]

    New Synthetic Approach to a [1.1.6] Metapara Cyclophane Derivative via Suzuki,Miyaura Cross-Coupling and Ring-Closing Metathesis,

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 9 2005
    Sambasivarao Kotha
    Abstract The synthesis of a [1.1.6] metapara cyclophane derivative, 1,5(1,4),3(1,3)-tribenzenacycloundecaphan-8-ene-6,11-dione, has been achieved via the Suzuki,Miyaura cross-coupling of ,,,,-dibromo- m -xylene with an arylboronic acid derivative followed by an allylation and ring-closing metathesis reaction sequence. [source]

    Design of Living Ring-Opening Alkyne Metathesis,

    ANGEWANDTE CHEMIE, Issue 40 2010
    Dr. Felix R. Fischer
    Es lebt: Ein gespanntes cyclisches Alkin mit Dibenzo[a,e][8]annulen-Struktur geht eine Ringöffnungsmetathesepolymerisation (ROMP) zur Bildung eines hochmolekularen Poly(ortho -phenylens) mit alternierenden Ethyl- und Ethinylbrücken entlang dem Polymerrückgrat ein. Der Molybdänalkylidin-Katalysator wurde gezielt darauf abgestimmt, zwischen gespannten und ungespannten Alkinen unterscheiden zu können, und es resultiert ein lebendes Polymer mit beispiellos niedriger Polydispersität. [source]

    Probing the Mechanism of Olefin Metathesis in Grubbs,Hoveyda and Grela Type Complexes,

    ANGEWANDTE CHEMIE, Issue 32 2010
    Tim Vorfalt Dipl.-Ing.
    Je mehr, desto besser: Kinetische Daten aus UV/Vis-Messungen liefern schlüssige Hinweise für die Beteiligung des olefinischen Substrats am geschwindigkeitsbestimmenden Schritt der Initiierungsreaktion von Olefinmetathesekatalysatoren vom Grubbs-Hoveyda-Typ sowie für einen zweiten, Olefin-unabhängigen Schritt, der nur bei sehr hohen Olefinkonzentrationen geschwindigkeitsbestimmend wird. [source]

    Integrating the Schrock and Grubbs Catalysts: Ruthenium,Binaphtholate Catalysts for Olefin Metathesis,

    ANGEWANDTE CHEMIE, Issue 22 2010
    Johanna
    Glücklich vereint: Die Einführung eines atropisomeren Binaphtholat-Liganden in Grubbs-Rutheniumkatalysatoren durch Reaktion von K2(bino) mit [RuCl2(NHC)(py)2(CHPh)] in Pyridin führte in guten bis ausgezeichneten Ausbeuten zu chiralen Ruthenium-bino-Komplexen (siehe Schema; bino=1,1,-Binaphthyl-2,2,-diolat, py=Pyridin, NHC=IMes, H2IMes; IMes=N,N,-Bis(mesityl)imidazol-2-yliden; L=PCy3 oder (py)2). [source]

    ChemInform Abstract: A Convenient Approach to Acyclic Unsaturated Amino Acids via Ring-Closing Metathesis.

    CHEMINFORM, Issue 38 2010
    Hani Mutlak A. Hassan
    Abstract An efficient synthesis of conformationally restricted cis- and trans-unsaturated amino acids (III) and (V) via lactams (II) or macrolactam (IV) is described. [source]

    ChemInform Abstract: Low Catalyst Loadings in Olefin Metathesis: Synthesis of Nitrogen Heterocycles by Ring-Closing Metathesis: Synthesis of Nitrogen Heterocycles by Ring-Closing Metathesis.

    CHEMINFORM, Issue 29 2010
    Kevin M. Kuhn
    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 Highly Regioselective Ring-Opening Metathesis , Cross Metathesis Process Modulated by the Electronic Effects of the Cross Metathesis Partner: An Entry to Quaternary Prolines.

    CHEMINFORM, Issue 27 2009
    Javier Carreras
    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-Hydroxypyridines Using Ruthenium-Catalyzed Ring-Closing Olefin Metathesis.

    CHEMINFORM, Issue 25 2009
    Kazuhiro Yoshida
    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 Diversity-Oriented Approach to Diphenylalkanes by Strategic Utilization of [2 + 2 + 2] Cyclotrimerization, Cross-Enyne Metathesis and Diels,Alder Reaction.

    CHEMINFORM, Issue 23 2009
    Sambasivarao Kotha
    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: Olefin Metathesis Based Approach to Diversely Functionalized Pyrrolidizidines and Indolizidines; Total Synthesis of (+)-Monomorine.

    CHEMINFORM, Issue 21 2009
    Giordano Lesma
    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: Phosphine-Catalyzed Disulfide Metathesis.

    CHEMINFORM, Issue 14 2009
    Remi Caraballo
    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: Acceleration Effect of an Allylic Hydroxy Group on Ring-Closing Enyne Metathesis of Terminal Alkynes: Scope, Application, and Mechanistic Insights.

    CHEMINFORM, Issue 13 2009
    Tatsushi Imahori
    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 ,-Alkylidene ,,,-Unsaturated ,-Lactones by Ring-Closing Metathesis: Application to the Synthesis of the C1,C8 Subunit of Biselide E.

    CHEMINFORM, Issue 8 2009
    Anne-Frederique Salit
    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: Ring-Closing Olefin Metathesis in the Aqueous Phase of Amphiphilic Conetworks Consisting of Fluorophilic and Hydrophilic Compartments.

    CHEMINFORM, Issue 7 2009
    Eva M. Hensle
    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 Calix[4]arenocrowns via Ring-Closing Metathesis.

    CHEMINFORM, Issue 5 2009
    Lin-Gang Lu
    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 a Natural Product-Inspired Eight-Membered Ring Lactam Library via Ring-Closing Metathesis.

    CHEMINFORM, Issue 3 2009
    Neil Brown
    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: Ring-Closing Metathesis for the Synthesis of a Highly G-Quadruplex Selective Macrocyclic Hexaoxazole Having Enhanced Cytotoxic Potency.

    CHEMINFORM, Issue 46 2008
    Mavurapu Satyanarayana
    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: Design and Synthesis of Spiro-heterocycles by Ring-Closing Metathesis.

    CHEMINFORM, Issue 45 2008
    Sambasivarao Kotha
    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]