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Search for "oxonium" in Full Text gives 55 result(s) in Beilstein Journal of Organic Chemistry.

Molecular rearrangements of superelectrophiles

  • Douglas A. Klumpp

Beilstein J. Org. Chem. 2011, 7, 346–363, doi:10.3762/bjoc.7.45

Graphical Abstract
  • present in the substrate, dicationic species can be produced. For example, the pentan-1-ol derivative 74 reacts with ozone in magic acid to yield dication 75 quantitatively (Scheme 15). This conversion involves protonation of the hydroxy group to give the oxonium ion 76 and reaction of O3H+ at the methine
  • thought to be involved. In superacidic media, substrates such as ethylene glycol (159) are diprotonated and form the bis-oxonium ions, i.e., 160 as a stable species at −80 °C. When the solution is warmed to 25 °C, protonated acetaldehyde (162) is formed (Scheme 32). The conversion may occur by one of
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Review
Published 23 Mar 2011

Shelf-stable electrophilic trifluoromethylating reagents: A brief historical perspective

  • Norio Shibata,
  • Andrej Matsnev and
  • Dominique Cahard

Beilstein J. Org. Chem. 2010, 6, No. 65, doi:10.3762/bjoc.6.65

Graphical Abstract
  • ) [22]. O-(Trifluoromethyl)oxonium salts All the previously described reagents allow trifluoromethylation only of soft nucleophiles and there is no possibility of preparing N-CF3 or O-CF3 compounds by direct trifluoromethylation via these compounds. O-Trifluoromethyl oxonium salts were anticipated to
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Review
Published 16 Jun 2010

Prins fluorination cyclisations: Preparation of 4-fluoro-pyran and -piperidine heterocycles

  • Guillaume G. Launay,
  • Alexandra M. Z. Slawin and
  • David O'Hagan

Beilstein J. Org. Chem. 2010, 6, No. 41, doi:10.3762/bjoc.6.41

Graphical Abstract
  • hydrogen fluoride salts (Et4NF·5HF) as the reaction medium, without the requirement for BF3·OEt2 [14][15]. These reactions with fluoride follow from the much more commonly observed Prins reactions of halides (Cl−, Br− and I−) other than fluoride in the quenching of the intermediate oxonium intermediate [16
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Full Research Paper
Published 26 Apr 2010

A stable enol from a 6-substituted benzanthrone and its unexpected behaviour under acidic conditions

  • Marc Debeaux,
  • Kai Brandhorst,
  • Peter G. Jones,
  • Henning Hopf,
  • Jörg Grunenberg,
  • Wolfgang Kowalsky and
  • Hans-Hermann Johannes

Beilstein J. Org. Chem. 2009, 5, No. 31, doi:10.3762/bjoc.5.31

Graphical Abstract
  • process as discussed above via the enolate 8 as an intermediate. From this, the enol 4 is generated under the influence of the added acid. Further protonation provides the oxonium ion 9 which is set up for a retro-[2+4]-cycloaddition (see transition state 10) to lose hydrogen and finally become
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Full Research Paper
Published 16 Jun 2009

The use of silicon- based tethers for the Pauson- Khand reaction

  • Adrian P. Dobbs,
  • Ian J. Miller and
  • Saša Martinović

Beilstein J. Org. Chem. 2007, 3, No. 21, doi:10.1186/1860-5397-3-21

Graphical Abstract
  • from the reaction of allyldimethylpent-4-ynyloxysilane with tungsten pentacarbonyl, possibly formed via oxidation of THF to give an oxonium ion followed by addition of the alcohol cleaved from the silyl ether (Figure 3). In order to investigate if the presence of the silicon linker was preventing the
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Preliminary Communication
Published 06 Jul 2007
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