• compounds
  • By using palladium( II ) chloride as a catalyst and Xantphos as a ligand, the reaction of P(O)H compounds, alkynes, and ethyl difluoroiodoacetate proceeds with moderate to high yields, and provides an attractive approach for the construction of ( E )-γ,γ-difluoroalkenylphosphine oxides. (rsc.org)
  • Commercially, the dominant alkyne is acetylene itself, which is used as a fuel and a precursor to other compounds, e.g., acrylates. (wikipedia.org)
  • regio
  • The first phosphinodifluoroalkylation of alkynes is achieved and the simultaneous addition of both difluoromethylene and phosphinoyl groups across the alkynes with high regio- and stereoselectivity is of great significance. (rsc.org)
  • In addition to high-order polymers and dimers and trimers, which originate from low regio- and chemoselectivities, enyne side products derived from alkyne dimerization have been observed. (wikipedia.org)
  • molybdenum
  • The Bailey system utilized a mixture of tungsten and silicon oxides at temperatures as high as 450 °C. In 1974 Mortreux reported the use of a homogeneous catalyst-molybdenum hexacarbonyl at 160 °C-to observe an alkyne scrambling phenomenon, in which an unsymmetrical alkyne equilibrates with its two symmetrical derivatives. (wikipedia.org)
  • cycloaddition
  • 2) the third alkyne participates in [4+cycloaddition to generate a bicyclic species (a metallanorbornadiene). (wikipedia.org)
  • Other methods for the direct formation of aromatic rings from substituted, unsaturated precursors include the Dötz reaction, palladium-catalyzed [4+benzannulation of enynes with alkynes, and Lewis-acid-mediated [4+cycloaddition of enynes with alkynes. (wikipedia.org)
  • A notable variant of the Huisgen 1,3-dipolar cycloaddition is the copper(I) catalyzed variant, no longer a true concerted cycloaddition, in which organic azides and terminal alkynes are united to afford 1,4-regioisomers of 1,2,3-triazoles as sole products (substitution at positions 1' and 4' as shown above). (wikipedia.org)
  • Internal
  • Internal alkynes feature carbon substituents on each acetylenic carbon. (wikipedia.org)
  • The thiocarbamoylation of internal alkynes to produce tetrasubstituted β-aminocarbonyl vinyl sulfides was demonstrated using a nickel catalyst. (rsc.org)
  • alkane
  • A less efficient catalyst, Lindlar's catalyst , prepared by deactivating (or poisoning) a conventional palladium catalyst by treating it with lead acetate and quinoline, permits alkynes to be converted to alkenes without further reduction to an alkane. (msu.edu)
  • Alkyne has 4 fewer hydrogens than an alkane. (slideserve.com)
  • catalyst
  • The Lindlar catalyst permits adsorption and reduction of alkynes, but does not adsorb alkenes sufficiently to allow their reduction. (msu.edu)
  • The NHC-Au-OTf [NHC = 1,3-bis(2,6-di-isopropylphenyl)-imidazol-2-ylidene] catalyst was tested in the alkoxylation and hydration of alkynes in a wide set of neoteric solvents for the first time. (rsc.org)
  • Steric bulk on the alkyne coupling partners and catalyst have been invoked as the controlling elements of regioselectivity. (wikipedia.org)
  • intermediates
  • Alkynes also serve as important synthetic intermediates in a number of organic transformations, and their chemistry has recently received particular attention with respect to new materials. (docme.ru)
  • potassium
  • HO-CH2C≡C-(CH2)6CH3 → HO(CH2)8-C≡CH The alkyne zipper reaction requires a strong base, which can be generated from the reaction of potassium hydride and a diamine: The potassium 3-aminopropylamide deprotonates the less-substituted methylene adjacent to the alkyne group. (wikipedia.org)
  • The Seyferth-Gilbert homologation is a chemical reaction of an aryl ketone 1 (or aldehyde) with dimethyl (diazomethyl)phosphonate 2 and potassium tert-butoxide to give substituted alkynes 3. (wikipedia.org)
  • The generation of nitrogen gas gives a vinyl carbene G, which via a 1,2-migration forms the desired alkyne H. Dimethyl (diazomethyl)phosphonate can be generated in situ from dimethyl-1-diazo-2-oxopropylphosphonate (also called the Ohira-Bestmann reagent) by reaction with methanol and potassium carbonate. (wikipedia.org)
  • triple bond
  • The 3-aminopropylamine anion attacks the same lesser-substituted carbon adjacent to the allene, removing a proton and catalyzing a similar process, where the electrons from the carbon-hydrogen bond move to form a triple-bond (an alkyne). (wikipedia.org)
  • atom
  • When bonded side-on to a single metal atom, an alkyne serves as a dihapto usually two-electron donor. (wikipedia.org)
  • group
  • The longest continuous chain with functional group is no in the direction that gives the alkyne functional group suffix as low no as possible. (slideserve.com)
  • BSA contains a thiol group at Cys-34 which is functionalized with an alkyne group. (wikipedia.org)