Synthesis, structural analysis, and chiral investigations of some atropisomers with EE-tetrahalogeno-1,3-butadiene core
| Autor: | Nicolas Vanthuyne, Crina Cismas, Jean Roncali, Christian Roussel, Anamaria Terec, Jean-Valère Naubron, Ion Grosu, Flavia Piron, Richard A. Varga, Bérangère Joulin |
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| Přispěvatelé: | MOLTECH-Anjou, Université d'Angers (UA)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2009 |
| Předmět: |
Atropisomer
Bromine 010405 organic chemistry Stereochemistry Organic Chemistry Absolute configuration chemistry.chemical_element 1 3-Butadiene 010402 general chemistry 01 natural sciences 0104 chemical sciences Chiral column chromatography symbols.namesake chemistry.chemical_compound chemistry Computational chemistry Halogen symbols [CHIM]Chemical Sciences Van der Waals radius Enantiomer |
| Zdroj: | Journal of Organic Chemistry Journal of Organic Chemistry, American Chemical Society, 2009, 74 (23), pp.9062-9070. ⟨10.1021/jo901762j⟩ |
| ISSN: | 1520-6904 0022-3263 |
| DOI: | 10.1021/jo901762j⟩ |
| Popis: | International audience; The atropenantiomers of stable 1,2,3,4-tetrahalo-1,3-butadiene derivatives (where halogeno stands for bromine or iodine) were separated with use of chiral HPLC. The barriers for the enantiomerization process were determined on-line by dynamic HPLC (DHPLC) or off-line by classical kinetic measurements. In the case of the tetrachloro compound, the barrier was too low for DHPLC and its value was obtained by dynamic NMR experiments. The obtained barriers for chloro, bromo, and iodo derivatives correlate with the van der Waals radii of the halogens. The absolute configuration of the isolated enantiomers of the tetraiodo and tetrabromo compounds was assigned by comparison of the experimental and conformations averaged calculated VCD spectra. The identification of a signature band of the absolute configuration of the butadiene core, the sign and location of which are independent from the different conformations and substituents, allowing the safe assignment of the absolute configuration of the enantiomers of chiral 1,3-butadienes, is also reported. |
| Databáze: | OpenAIRE |
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