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Search for "BDE" in Full Text gives 27 result(s) in Beilstein Journal of Organic Chemistry.

Part 3. Triethylborane- air: a suitable initiator for intermolecular radical additions of S-2-oxoalkyl- thionocarbonates (S-xanthates) to olefins

  • Jean Boivin and
  • Van Tai Nguyen

Beilstein J. Org. Chem. 2007, 3, No. 47, doi:10.1186/1860-5397-3-47

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  • . Fortunately, such an increase of reaction temperature enhances route c much more than route b. For planar radicals, Rüchardt and Beckwith established that the C-H bond dissociation energy (BDE) for H-CXYZ compounds displays a good linear correlation with the measured α and β-proton ESR hyperfine splitting
  • constants. [17][18][19] When Y = Me, Z = H, the H-C BDE follows the order for X: CH=CH2 < Ph < PhCO = MeCO < CN < CO2Et < Me (Table 3, entries 1–7). The BDE for compounds where Y = Z = H follows the same order, albeit the value is of course slightly higher when compared to their methylated counterparts
  • presence of Et3B. Addition of xanthate 1a to decene at r.t., catalysed by Et3B/air Et3B/air catalysed intermolecular radical additions to olefins Selected values of H-C BDE for compounds H-CXYZ from references [17][18][19]. Supporting Information Supporting Information File 117: General procedure for
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Published 13 Dec 2007

Part 2. Mechanistic aspects of the reduction of S-alkyl- thionocarbonates in the presence of triethylborane and air

  • Florent Allais,
  • Jean Boivin and
  • Van Tai Nguyen

Beilstein J. Org. Chem. 2007, 3, No. 46, doi:10.1186/1860-5397-3-46

Graphical Abstract
  • found. A more seemly hypothesis is a hydrogen abstraction from the α-position of the boron atom. This reaction is well documented and energetically acceptable (BDE (C-H) = 80 ± 3 kcal/mol). For example, the methyl radical abstracts α-boronyl hydrogen of Et3B 124 times faster than hydrogen in the methyl
  • role of water or alcohols and solvents in the reduction of S-alkylxanthates and related compounds. Hydrogen transfer from the O-H bond present in water or in an alcohol is not an obvious hypothesis in radical chemistry because of the high BDE of the O-H bond. Our results corroborate Wood's findings
  • a complexation would lower the BDE of the O-H bond by 30 kcal/mol when compared to free H2O, thus rendering hydrogen abstraction from water a plausible process. The second route implies hydrogen abstraction from •O-O-H radical (O-H BDE 47.6 kcal/mol). The latter could possibly be formed by
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Published 12 Dec 2007
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