نتایج جستجو برای: alkyne

تعداد نتایج: 2429  

Journal: :Journal of nuclear medicine : official publication, Society of Nuclear Medicine 2013
Dexing Zeng Brian M Zeglis Jason S Lewis Carolyn J Anderson

Click chemistry has become a ubiquitous chemical tool with applications in nearly all areas of modern chemistry, including drug discovery, bioconjugation, and nanoscience. Radiochemistry is no exception, as the canonical Cu(I)-catalyzed azide-alkyne cycloaddition, strain-promoted azide-alkyne cycloaddition, inverse electron demand Diels-Alder reaction, and other types of bioorthogonal click lig...

2009
Hunaid Nulwala Kenichi Takizawa Anika Odukale Anzar Khan Raymond J. Thibault Benjamin R. Taft Bruce H. Lipshutz Craig J. Hawker

The synthesis of isomeric, functionalized 4-vinyl-1,2,3-triazole and 5-vinyl-1,2,3-triazole monomers is demonstrated using heterogeneous copper (copper-in-charcoal)-catalyzed azide-alkyne cycloaddition (CuAAC) or homogeneous ruthenium (Ru)-catalyzed azide-alkyne cycloadditions (RuAAC) “click” protocols. These reactions are regiospecific, exclusively forming 1,4and 1,5-disubstituted triazoles as...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2011
Afaf H El-Sagheer A Pia Sanzone Rachel Gao Ali Tavassoli Tom Brown

A triazole mimic of a DNA phosphodiester linkage has been produced by templated chemical ligation of oligonucleotides functionalized with 5'-azide and 3'-alkyne. The individual azide and alkyne oligonucleotides were synthesized by standard phosphoramidite methods and assembled using a straightforward ligation procedure. This highly efficient chemical equivalent of enzymatic DNA ligation has bee...

Journal: :Organic & biomolecular chemistry 2009
Jian-Hong Zhang Ying Cheng

The first study on the reaction of C(+)-C-Se(-) 1,3-dipoles with electron-deficient alkenes and alkyne is reported. 2-Arylselenocarbamoylthiazolium inner salts, the unique thiazole carbene-derived C(+)-C-Se(-) 1,3-dipoles, reacted efficiently with methoxycarbonylallenes or dimethyl acetylenedicarboxylate to produce dihydroselenophenes or selenopheno[2,3-b]pyrazines, respectively, in high yields...

Journal: :Nanoscale 2015
Fuwu Zhang Justin A Smolen Shiyi Zhang Richen Li Parth N Shah Sangho Cho Hai Wang Jeffery E Raymond Carolyn L Cannon Karen L Wooley

In this study, a new type of degradable polyphosphoester-based polymeric nanoparticle, capable of carrying silver cations via interactions with alkyne groups, has been developed as a potentially effective and safe treatment for lung infections. It was found that up to 15% (w/w) silver loading into the nanoparticles could be achieved, consuming most of the pendant alkyne groups along the backbon...

Journal: :Organic & biomolecular chemistry 2015
Xiang Li Suyan Sun Fan Yang Jianxun Kang Yusheng Wu Yangjie Wu

An efficient and generally applicable protocol for palladium-catalyzed oxidative deacetonative coupling of 4-aryl-2-methyl-3-butyn-2-ols with dialkyl H-phosphonates has been developed. This methodology provides a new and practical route to alkynylphosphonates using the inexpensive 4-aryl-2-methyl-3-butyn-2-ols as the alkyne sources. This reaction could also be performed with aryl bromides, 2-me...

Journal: :Organic & biomolecular chemistry 2012
André H St Amant Leslie A Bean J Peter Guthrie Robert H E Hudson

The synthesis of nucleoside analogues incorporating 4-(5-pyrimidinyl)-1,2,3-triazole aglycons as expanded purine nucleobase mimics were accessed using the copper-catalyzed azide-alkyne Huisgen cycloaddition between a ribosyl azide and 5-alkynylpyrimidines. Depending on the nature of the alkyne employed, other nucleoside analogues that possess fluorescence or potential metal-binding properties w...

Journal: :Chemical science 2011
Matthew J Campbell F Dean Toste

A racemic Au(I)-catalyzed three-component reaction has been developed to prepare cyclic carbamimidates from imines, terminal alkynes, and sulfonylisocyanates. This reaction exploits the carbophilic π-acidity of gold catalysts to first activate an alkyne toward deprotonation and secondly, to activate the internal alkyne generated toward intramolecular O-cyclization. Unlike similar previously rep...

2015
Thomas P Robinson Jose M Goicoechea

We report that the 2-phosphaethynolate anion (PCO(-)) reacts with propargylamines in the presence of a proton source to afford novel N-derivatized phosphinecarboxamides bearing alkyne functionalities. Deprotonation of these species gives rise to novel five- and six-membered anionic heterocycles resulting from intramolecular nucleophilic attack of the resulting phosphide at the alkyne functional...

Journal: :Journal of the American Chemical Society 2015
Malkanthi K Karunananda Neal P Mankad

A unique cooperative H2 activation reaction by heterobimetallic (NHC)M'-MCp(CO)2 complexes (NHC = N-heterocyclic carbene, M' = Cu or Ag, M = Fe or Ru) has been leveraged to develop a catalytic alkyne semi-hydrogenation transformation. The optimal Ag-Ru catalyst gives high selectivity for converting alkynes to E-alkenes, a rare selectivity mode for reduction reactions with H2. The transformation...

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