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Alkynes

Distribution by Scientific Domains
Chemistry93%
Polymers and Materials Science6%
Distribution within Chemistry
Organic Chemistry58%
General & Introductory Chemistry22%
11 Other Subdomains20%

Kinds of Alkynes

  • internal alkyne
    		•
  • terminal alkyne
    		•

    Terms modified by Alkynes

  • alkyne cycloaddition
  • alkyne groups
    		•
  • alkyne hydroamination
  • alkyne insertion
    		•
  • alkyne metathesis
  • alkyne unit
    		•

    Selected Abstracts

    Silica-Immobilized NHC,CuI Complex: An Efficient and Reusable Catalyst for A3 -Coupling (Aldehyde,Alkyne,Amine) under Solventless Reaction Conditions

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 13 2008
    Min Wang
    Abstract A novel silica-immobilized NHC,CuI complex was developed and used as a highly efficient catalyst in the three-component coupling reactions of aldehydes, alkynes and amines (A3 -coupling). The reactions were applicable to aromatic and aliphatic aldehydes, alkynes and amines, and generated the corresponding propargylamines in good yields only in the presence of SiO2,NHC,CuI (2 mol-%) at room temp. under solvent-free reaction conditions. Moreover, the catalyst was quantitatively recovered from the reaction mixture by a simple filtration and reused for ten cycles with almost consistent activity.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

    Gold Catalysis: Alkylideneoxazolines and -oxazoles from Intramolecular Hydroamination of an Alkyne by a Trichloroacetimidate

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 21 2006
    A. Stephen K. Hashmi
    Abstract Several propargylic trichloroacetimidates have been prepared and their reactions with gold catalysts studied. Only with the propargyl and the 1-methylpropargyl substituent was a selective cyclization observed; with gold(III) chloride in acetonitrile only the product of a fast hydroamination to 4-methylene-4,5-dihydrooxazoles was obtained, in chloroform the slower subsequent aromatization could not be prevented which delivered the oxazoles after long reaction times. Up to 3333 turnovers could be reached. With gold(I) catalysts in chloroform or dichloromethane selective hydroamination to 4-methylene-4,5-dihydrooxazoles without subsequent aromatization was exclusively observed. The gold(I) catalysts also allowed chemoselective cycloisomerization of N -propargylcarboxamides to 5-methylene-4,5-dihydrooxazoles. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]

    Oligonucleotides Containing 7-Deaza-2,-deoxyinosine as Universal Nucleoside: Synthesis of 7-Halogenated and 7-Alkynylated Derivatives, Ambiguous Base Pairing, and Dye Functionalization by the Alkyne,Azide ,Click' Reaction

    HELVETICA CHIMICA ACTA, Issue 7 2008
    Frank Seela
    Abstract Oligonucleotides containing 7-deaza-2,-deoxyinosine derivatives bearing 7-halogen substituents or 7-alkynyl groups were prepared. For this, the phosphoramidites 2b,2g containing 7-substituted 7-deaza-2,-deoxyinosine analogues 1b,1g were synthesized (Scheme,2). Hybridization experiments with modified oligonucleotides demonstrate that all 2,-deoxyinosine derivatives show ambiguous base pairing, as 2,-deoxyinosine does. The duplex stability decreases in the order Cd>Ad>Td>Gd when 2b,2g pair with these canonical nucleosides (Table,6). The self-complementary duplexes 5,-d(F7c7I-C)6, d(Br7c7I-C)6, and d(I7c7I-C)6 are more stable than the parent duplex d(c7I-C)6 (Table,7). An oligonucleotide containing the octa-1,7-diyn-1-yl derivative 1g, i.e., 27, was functionalized with the nonfluorescent 3-azido-7-hydroxycoumarin (28) by the Huisgen,Sharpless,Meldal cycloaddition ,click' reaction to afford the highly fluorescent oligonucleotide conjugate 29 (Scheme,3). Consequently, oligonucleotides incorporating the derivative 1g bearing a terminal CC bond show a number of favorable properties: i) it is possible to activate them by labeling with reporter molecules employing the ,click' chemistry. ii) Space demanding residues introduced in the 7-position of the 7-deazapurine base does not interfere with duplex structure and stability (Table,8). iii) The ambiguous pairing character of the nucleobase makes them universal probes for numerous applications in oligonucleotide chemistry, molecular biology, and nanobiotechnology. [source]

    Semiconductor-Gold Nanocomposite Catalysts for the Efficient Three-Component Coupling of Aldehyde, Amine and Alkyne in Water

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 17 2009
    Leng Leng Chng
    Abstract An efficient heterogeneous lead sulfide-gold catalyst has been successfully developed for the synthesis of propargylic amines via a three-component coupling reaction of aldehyde, amine and alkyne in water. The process is simple and applicable to a diverse range of aromatic and aliphatic aldehydes, amines and alkynes. Furthermore, the catalyst is stable to air and water, and can be easily recovered and reused. [source]

    Efficient Activation of 2-Iminomethylpyridine/Cobalt-Based Alkyne [2+2+2],Cycloaddition Catalyst by Addition of a Silver Salt

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2007
    Avijit Goswami
    Abstract The addition of silver triflate (AgOTf) or silver hexafluoroantimonate (AgSbF6) significantly increased the activity of the 2-(arylimino)methylpyridine/cobalt(II) chloride hexahydrate (CoCl2,6,H2O)/zinc catalyst in alkyne cyclotrimerizations thereby accelerating the reaction and enabling the use of unactivated, simple internal alkynes as the monoyne substrate: The rate of reaction was found to be highly dependent on the nature of the counter anion (X,) and the ligand (L) in the postulated cationic cobalt(I) complex [LCo(I)]+X,. [source]

    Synthesis of Well-Defined Telechelic Macrophotoinitiator of Polystyrene by Combination of ATRP and Click Chemistry

    MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 19 2009
    Mustafa Degirmenci
    Abstract A new well-defined telechelic macrophotoinitiator of polystyrene was synthesized by combination of ATRP and click chemistry. The ATRP of styrene by means of 2-oxo-1,2-diphenylethyl-2-bromopropanoate (PI-Br) initiator with CuBr/2,2,-bipyridine yields polystyrene with photoactive benzoin (PI) and bromine (Br) group (PI-PSt-Br). Subsequently, PI-PSt-Br was converted to PI-PSt-N3 by simple nucleophilic substitution reaction. Alkyne functionalized benzoin (PI-alkyne) was synthesized by using benzoin photoinitiator and propargyl bromide. Then the coupling reaction between PI-PSt-N3 and PI-alkyne was performed by Cu(I) catalysis. The spectroscopic studies revealed that low-polydispersity polystyrene with desired photoinitiator functionality at both end of the chain, PI-PSt-PI, was obtained. [source]

    Synthesis of poly(cyclohexene oxide)- block -polystyrene by combination of radical-promoted cationic polymerization, atom transfer radical polymerization and click chemistry

    POLYMER INTERNATIONAL, Issue 6 2010
    Mustafa Degirmenci
    Abstract The combination of radical-promoted cationic polymerization, atom transfer radical polymerization (ATRP) and click chemistry was employed for the efficient preparation of poly(cyclohexene oxide)- block -polystyrene (PCHO- b -PSt). Alkyne end-functionalized poly(cyclohexene oxide) (PCHO-alkyne) was prepared by radical-promoted cationic polymerization of cyclohexene oxide monomer in the presence of 1,2-diphenyl-2-(2-propynyloxy)-1-ethanone (B-alkyne) and an onium salt, namely 1-ethoxy-2-methylpyridinium hexafluorophosphate, as the initiating system. The B-alkyne compound was synthesized using benzoin photoinitiator and propargyl bromide. Well-defined bromine-terminated polystyrene (PSt-Br) was prepared by ATRP using 2-oxo-1,2-diphenylethyl-2-bromopropanoate as initiator. Subsequently, the bromine chain end of PSt-Br was converted to an azide group to obtain PSt-N3 by a simple nucleophilic substitution reaction. Then the coupling reaction between the azide end group in PSt-N3 and PCHO-alkyne was performed with Cu(I) catalysis in order to obtain the PCHO- b -PSt block copolymer. The structures of all polymers were determined. Copyright © 2010 Society of Chemical Industry [source]

    [4+2],Cycloaddition Reaction of Cyclic Alkyne,{Co2(CO)6} Complexes with Dienes,

    ANGEWANDTE CHEMIE, Issue 41 2010
    Prof.
    Eine allgemeine Vorschrift für die Titelreaktion wurde entwickelt. Sie lässt sich auf zahlreiche acyclische 1,3-Diene und cyclische Alkin-{Co2(CO)6}-Komplexe anwenden und liefert nach oxidativer Aufarbeitung unterschiedliche Arten benzanellierter mittlerer Ringe (siehe Schema). Interessant ist, dass die [4+2]-Cycloaddition bevorzugt statt der Pauson-Khand-Reaktion abläuft. [source]

    Protein Modification by Strain-Promoted Alkyne,Nitrone Cycloaddition,

    ANGEWANDTE CHEMIE, Issue 17 2010
    Xinghai Ning
    Schnell und zielsicher: Für die metallfreie 1,3-dipolare Cycloaddition von Dibenzocyclooctinen mit Nitronen wurden Geschwindigkeitskonstanten bis 39,M,1,s,1 ermittelt, sodass diese Reaktion bis zu 300-mal schneller abläuft als ähnliche Reaktionen mit Aziden. Die Strategie ist nützlich für die ortsspezifische N-terminale Modifizierung von Peptiden und Proteinen. [source]

    ChemInform Abstract: Unprecedented Cu(I)-Catalyzed Microwave-Assisted Three-Component Coupling of a Ketone, an Alkyne, and a Primary Amine.

    CHEMINFORM, Issue 43 2010
    Olga P. Pereshivko
    Abstract The title reaction ("KA2 coupling") represents a general approach to various secondary propargylamines. [source]

    ChemInform Abstract: Fe3O4 Nanoparticles: A Robust and Magnetically Recoverable Catalyst for Three-Component Coupling of Aldehyde, Alkyne and Amine.

    CHEMINFORM, Issue 34 2010
    Tieqiang Zeng
    No abstract is available for this article. [source]

    ChemInform Abstract: Semiconductor-Gold Nanocomposite Catalysts for the Efficient Three-Component Coupling of Aldehyde, Amine and Alkyne in Water.

    CHEMINFORM, Issue 12 2010
    Leng Leng Chng
    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: Gallium(III) Chloride Catalyzed Three-Component Coupling of Naphthol, Alkyne and Aldehyde: A Novel Synthesis of 1,3-Disubstituted-3H-benzo[f]chromenes.

    CHEMINFORM, Issue 5 2010
    J. S. Yadav
    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: Heterogeneously Catalyzed Efficient Alkyne,Alkyne Homocoupling by Supported Copper Hydroxide on Titanium Oxide.

    CHEMINFORM, Issue 51 2009
    Takamichi Oishi
    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]

    Silica-Immobilized CuI: An Efficient Reusable Catalyst for Three-Component Coupling Reaction of Aldehyde, Amine and Alkyne.

    CHEMINFORM, Issue 52 2007
    Pravin R. Likhar
    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]

    A Highly Efficient Three-Component Coupling of Aldehyde, Terminal Alkyne, and Amine via C,H Activation Catalyzed by Reusable Immobilized Copper in Organic,Inorganic Hybrid Materials under Solvent-Free Reaction Conditions.

    CHEMINFORM, Issue 40 2007
    Pinhua Li
    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]

    Microwave-Promoted, Solvent-Free, Three-Component Coupling of Aldehyde, Alkyne, and Amine Catalyzed by AgNO3.

    CHEMINFORM, Issue 32 2007
    Tingting 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, please click on HTML or PDF. [source]

    Studies on the Zirconium-Mediated Alkyne,Aldehyde Coupling Reactions: A Facile Synthesis of Stereodefined Allylic Alcohols and (Z)-2-En-4-yn-1-ols.

    CHEMINFORM, Issue 23 2007
    Shenghai Guo
    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]

    Nickel-Catalyzed Conjugate Addition of Arylboron Reagents to ,,,-Unsaturated Carbonyl Compounds with the Aid of a Catalytic Amount of an Alkyne.

    CHEMINFORM, Issue 51 2006
    Eiji Shirakawa
    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]

    Phosphine-Triggered Complete Chemo-Switch: From Efficient Aldehyde,Alkyne,Amine Coupling to Efficient Aldehyde,Alkyne Coupling in Water.

    CHEMINFORM, Issue 6 2006
    Xiaoquan Yao
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Nickel-Catalyzed Regioselective Synthesis of Tetrasubstituted Alkene Using Alkylative Carboxylation of Disubstituted Alkyne.

    CHEMINFORM, Issue 21 2005
    Kazuya Shimizu
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Ruthenium-Catalyzed Cyclization of Epoxide with a Tethered Alkyne: Formation of Ketene Intermediates via Oxygen Transfer from Epoxides to Terminal Alkynes.

    CHEMINFORM, Issue 39 2004
    Reniguntala J. Madhushaw
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Tandem Thiyl Radical Addition and Cyclization of Chiral Hydrazones Using a Silicon-Tethered Alkyne.

    CHEMINFORM, Issue 7 2004
    Gregory K. Friestad
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    Alkyne and Ketone Induced Novel Cleavage of a C,C Bond and a C,Si Bond in Zirconacyclobutene,Silacyclobutene Fused Ring Compounds.

    CHEMINFORM, Issue 18 2003
    Tao Yu
    Abstract For Abstract see ChemInform Abstract in Full Text. [source]

    ChemInform Abstract: Cleavage of Carbon,Carbon Triple Bond of Alkyne via Hydroiminoacylation by Rh(I) Catalyst.

    CHEMINFORM, Issue 52 2001
    Chul-Ho Jun
    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: Inter- and Intramolecular Carbonylative Alkyne,Alkyne Coupling Reaction Mediated by Cobalt Carbonyl Complex.

    CHEMINFORM, Issue 13 2001
    Takanori Shibata
    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]

    Protecting-Group-Free Total Synthesis of Isoquinoline Alkaloids by Nickel-Catalyzed Annulation of o -Halobenzaldimine with an Alkyne as the Key Step

    CHEMISTRY - A EUROPEAN JOURNAL, Issue 1 2010
    Rajendra Prasad Korivi Dr.
    Abstract An efficient short total synthesis of benzo[c]phenanthridine alkaloids including oxyavicine, oxynitidine, and oxysanguinarine is described. Thus, N -methyl- o -bromobenzaldimines 1,b,d undergo regioselective cyclization with 4-(benzo[d][1,3]dioxol-5-yl)but-3-yn-1-ol (2,b) in the presence of [Ni(cod)2] (cod=1,5-cyclooctadiene). In situ oxidation of the resultant isoquinolinium salts gives isoquinolinone derivatives 5,b,d with benzo[d][1,3]dioxol-5-yl substitution at the C3 atom and a (CH2)2OH group at the C4 atom. Later, oxidation of the alcohol group in 5,b,d to the aldehyde moiety followed by acid-catalyzed cyclization and dehydration completes the total syntheses to give oxyavicine, oxynitidine, and oxysanguinarine in 67, 65, and 60,% yields, respectively. The synthesis requires four steps from o -bromobenzaldehyde derivatives. Transformations of these alkaloids to the other alkaloids in this family are also discussed herein. [source]

    Copper-Catalyzed Amine,Alkyne,Alkyne Addition Reaction: An Efficient Method For the Synthesis of ,,,-Alkynyl-,-amino Acid Derivatives

    CHEMISTRY - A EUROPEAN JOURNAL, Issue 43 2009
    Lei Zhou
    Abstract A simple and efficient method for the synthesis of ,,,-alkynyl-,-amino acid derivatives by a copper-catalyzed three-component amine,alkyne,alkyne addition reaction was developed. Various ,,,-alkynyl-,-amino acid derivatives were synthesized in moderate to good yields in one step. With chiral prolinol derivatives employed as the amine component, excellent diastereoselectivities (up to >99:1 diastereomeric ratio (dr)) were obtained. The scope of the reaction and further transformations of the resulting amino acid derivatives, such as deprotection and cyclization are also described. [source]

    Rhodium-Catalyzed Asymmetric [5+2] Cycloaddition of Alkyne,Vinylcyclopropanes

    CHEMISTRY - A EUROPEAN JOURNAL, Issue 35 2009
    Ryo Shintani Dr.
    Easy to scale: A rhodium-catalyzed asymmetric intramolecular [5+2] cycloaddition of alkyne,vinylcyclopropanes has been developed. High enantioselectivities of up to >99.5,% ee have been achieved by the use of a chiral phosphoramidite ligand. The reaction can be easily scaled up and the stereochemical model of the present catalysis has also been proposed. [source]

    Comment on "Disproving a Silicon Analog of an Alkyne with the Aid of Topological Analyses of the Electronic Structure and Ab Initio Molecular Dynamics Calculations"

    CHEMPHYSCHEM, Issue 4 2006
    Gernot Frenking Prof. Dr.
    Bond order of a silicon-silicon bond (1): The statement that the recently synthesized compound RSiSiR (1) (RSi[C(SiMe3)3]2CHMe2) has rather a double than a triple bond is challenged. Arguments are given which support the interpretation of the bonding situation in terms of two donor,acceptor bonds which are enhanced by one , bond (see picture). [source]