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Search for "photochemical isomerization" in Full Text gives 6 result(s) in Beilstein Journal of Organic Chemistry.

Photochromic derivatives of indigo: historical overview of development, challenges and applications

  • Gökhan Kaplan,
  • Zeynel Seferoğlu and
  • Daria V. Berdnikova

Beilstein J. Org. Chem. 2024, 20, 228–242, doi:10.3762/bjoc.20.23

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  • ) and N,N'-dimethyl-5,5',7,7'-tetrabromoindigo (12) showed similar photochemical isomerization in the chloroalkane solvents. Additionally, a slow photoreaction in benzene was detected for compound 12 [40]. 11 years later, Margerum and co-workers investigated the photochromic behavior of 11a and 12 using
  • particular, the lifetime of Z-11a in CCl4 was found to be only 3.1 s versus 18 h measured previously. Nevertheless, it was obvious that N,N'-dialkylindigos were prone to the reversible photochemical isomerization. In addition, it was also found that the thermal backward Z–E conversion of 11a and 12
  • isomerization and photochemical (only for 13a) isomerization [46]. Compounds 13 showed intrinsic planar chirality and their enantiomers could be separated by HPLC. Notably, upon thermal and photochemical isomerization of these compounds, no Z-isomers were detected and only the racemization took place. Such
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Published 07 Feb 2024

Norbornadiene-functionalized triazatriangulenium and trioxatriangulenium platforms

  • Roland Löw,
  • Talina Rusch,
  • Tobias Moje,
  • Fynn Röhricht,
  • Olaf M. Magnussen and
  • Rainer Herges

Beilstein J. Org. Chem. 2019, 15, 1815–1821, doi:10.3762/bjoc.15.175

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  • (NBD) and quadricyclanes (QC) attached to TATA and TOTA platforms which can be used to check if these accelerated rates and the spin change mechanism also apply to [2 + 2] cycloreversions (QC→NBD). Keywords: [2 + 2] cycloaddition; [2 + 2] cycloreversion; norbornadiene; photochemical isomerization
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Published 30 Jul 2019

Dialkyl dicyanofumarates and dicyanomaleates as versatile building blocks for synthetic organic chemistry and mechanistic studies

  • Grzegorz Mlostoń and
  • Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 2235–2251, doi:10.3762/bjoc.13.221

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  • [16]. However, the most efficient method for the synthesis of dialkyl dicyanomaleates Z-1 is the photochemical isomerization of the corresponding E-isomers. The reaction is performed in dichloromethane [17] and in the presence of benzophenone [18][19] or 1,4-dicyanobenzene [20] as photosensitizer. The
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Published 24 Oct 2017

Synthesis of 1-indanones with a broad range of biological activity

  • Marika Turek,
  • Dorota Szczęsna,
  • Marek Koprowski and
  • Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

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  • % enantiomeric excess (Scheme 33). 2-Methylbenzil (108) has been converted to 2-hydroxy-2-phenylindan-1-one (109) as a result of photochemical isomerization, in 90% yield (Scheme 34) [59]. Wagner et al. have reported that hexaisopropyl-, hexaethyl- and hexamethylbenzils 110a–c photocyclized to the corresponding
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Published 09 Mar 2017

Rearrangements of organic peroxides and related processes

  • Ivan A. Yaremenko,
  • Vera A. Vil’,
  • Dmitry V. Demchuk and
  • Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

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Published 03 Aug 2016

Cyclization of ortho-hydroxycinnamates to coumarins under mild conditions: A nucleophilic organocatalysis approach

  • Florian Boeck,
  • Max Blazejak,
  • Markus R. Anneser and
  • Lukas Hintermann

Beilstein J. Org. Chem. 2012, 8, 1630–1636, doi:10.3762/bjoc.8.186

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  • ), 45.0 (2 × CH2), 12.4 (2 × CH3) ppm. See Supporting Information File 1 for experimental details and NMR spectra of coumarins and the precursor 2’-hydroxycinnamates. Conditions for the cyclization of 2’-hydroxycinnamate and related precursors to coumarins. (a) Thermal cyclization [16]. (b) Photochemical
  • isomerization/cyclization [17]. (c) Lewis acid induced demethylation/cyclization [18]. Hypothetical catalytic cycle: Nucleophile-assisted cyclization of (E)-ethyl 2’-hydroxycinnamate (1) to coumarin (2). Proposed catalytic cycle, based on 31P NMR spectroscopic and color evidence. Screening of catalysts for
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Published 26 Sep 2012
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