Manmode, Sujit; Hussain, Nazar; Gamboa Marin, Oscar Javier; Kato, Atsushi; Veytia-Bucheli, José Ignacio; Vincent, Stéphanie P et Gauthier, Charles 
ORCID: https://orcid.org/0000-0002-2475-2050
(2023).
Thioarylation of 6-Amino-2,3,6-trideoxy-d-manno-oct-2-ulosonic Acid (IminoKdo): Access to 3,6-Disubstituted Picolinates and Mechanistic Insights
Chemistry
, vol. Ahead
.
e202303904.
DOI: 10.1002/chem.202303904.
(Sous Presse)
Résumé
In this work, we present a metal-free coupling protocol for the regio- and stereoselective C3-thioarylation of 6-amino-2,3,6-trideoxy-d-manno-oct-2-ulosonic acid (iminoKdo). The developed procedure enables the coupling of electron-rich, electron-deficient, and hindered arylthiols, providing a series of C3-modified iminoKdo derivatives in moderate to good yields. Elucidation of active species through controlled experimental studies and time-lapse 31P NMR analysis provides insights into the reaction mechanism. We demonstrate that, following a tandem Staudinger/aza-Witting reaction of an azido-containing keto ester, an inseparable equimolar mixture of imine/enamine is formed. The enamine then undergoes a Stork-like nucleophilic attack with the in situ-formed disulfide reagent, resulting in the formation of the coupling products. Additionally, we describe a rarely reported acid-promoted aromatization of the C3-thioarylated iminoKdo skeleton into 3,6-disubstituted picolinates, which are reminiscent of dichotomines.
| Type de document: | Article |
|---|---|
| Mots-clés libres: | 3-deoxy-D-manno-oct-2-ulosonic acid; Staudinger/aza-Wittig; iminosugars; picolinates; thioarylation |
| Centre: | Centre INRS-Institut Armand Frappier |
| Date de dépôt: | 04 janv. 2024 14:40 |
| Dernière modification: | 04 janv. 2024 14:40 |
| URI: | https://espace.inrs.ca/id/eprint/13909 |
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