Axially chiral Ni(II) complexes of α-amino acids: Separation of enantiomers and kinetics of racemization
Résumé
Herein we present design, synthesis, chiral HPLC resolution, and kinetics of racemization of axially chiral Ni(II) complexes of glycine and di-(benzyl)glycine Schiff bases. We found that while the ortho-fluoro derivatives are configuration-ally unstable, the pure enantiomers of corresponding axially chiral ortho-chloro-containing complexes can be isolated by preparative HPLC and show exceptional configurational stability (t 1/2 from 4 to 216 centuries) at ambient conditions. Synthetic implications of this discovery for the development of new generation of axially chiral auxiliaries, useful for general asymmetric synthesis of α-amino acids, are discussed.
Domaines
Chimie
Origine : Fichiers produits par l'(les) auteur(s)
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