Slight structural modulation around a pivotal bond: high impact on enantiomeric stability
| Autor: | Giulia Bossa, Marion Jean, Christian Roussel, Daniel Farran, Vincent Belot, Muriel Albalat, Nicolas Vanthuyne |
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| Přispěvatelé: | Institut des Sciences Moléculaires de Marseille (ISM2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS) |
| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | New Journal of Chemistry New Journal of Chemistry, 2021, 45 (35), pp.16039-16047. ⟨10.1039/d1nj03178c⟩ |
| ISSN: | 1369-9261 1144-0546 |
| DOI: | 10.1039/d1nj03178c |
| Popis: | International audience; Based on a N-arylthiazoline scaffold, 22 structures with a N-Caryl chiral axis were synthesized exhibiting a huge molecular diversity for the four flanking substituents around the pivotal bond. The determination of their corresponding rotational barriers by thermal kineticexperiments or from the analysis of plateau shape chiral HPLC chromatogram allowed to rank these compounds according to their enantiomeric stability : 4 rotamers, 5 isolable atropisomers (i.e. not enough robust to be handled without risk of racemization) and 13 stable atropisomers. The influence of the flanking substituents was investigated showing that a minor structural modification may result in a drastic change on the value of the rotational barrier. All these results offer a set data on structure-rotational barrier relationships very helpful to design molecules exhibiting chiral axis or to optimize the enantiomeric stability of such structure. To complete this study, the racemization pathways were examined thanks to X-Ray analysis and DFT calculations, highlighting the importance of the aromatic ring distortion during the transition state on the energetic cost of the rotation |
| Databáze: | OpenAIRE |
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