Observation of Hyperpositive Non-Linear Effect in Asymmetric Organozinc Alkylation in Presence of -Pyrrolidinyl Norephedrine.
Fiche publication
Date publication
juin 2022
Journal
Molecules (Basel, Switzerland)
Auteurs
Membres identifiés du Cancéropôle Est :
Dr BELLEMIN-LAPONNAZ Stéphane
Tous les auteurs :
Thierry T, Geiger Y, Bellemin-Laponnaz S
Lien Pubmed
Résumé
Phenomena related to asymmetric amplification are considered to be key to understanding the emergence of homochirality in life. In asymmetric catalysis, theoretical and experimental models have been studied to understand such chiral amplification, in particular based on non-linear effects. Three decades after the theoretical demonstration that a chiral catalyst, when not enantiopure, could be more enantioselective than its enantiopure counterpart, we show here a new experimental example of nonlinear hyperpositive effect. We report here our investigations in the enantioselective zinc-catalyzed alkylation of benzaldehyde with -pyrrolidinyl norephedrine as partially resolved chiral ligand, which shows a significant hyperpositive non-linear effect. A study of the underlying mechanism was conducted, which allows us to confirm a mechanism that implies a monomeric and a dimeric complex both catalyzing the reaction at a steady state and giving different enantioselectivities.
Mots clés
asymmetric catalysis, chiral amplification, nonlinear effect
Référence
Molecules. 2022 06 11;27(12):