Chiral differentiation of some cyclic β-amino acids by kinetic and fixed ligand methods
✍ Scribed by Anna R. M. Hyyryläinen; Jaana M. H. Pakarinen; Enik Forró; Ferenc Fülöp; Pirjo Vainiotalo
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 220 KB
- Volume
- 45
- Category
- Article
- ISSN
- 1076-5174
- DOI
- 10.1002/jms.1704
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✦ Synopsis
Abstract
Differentiation of β‐amino acid enantiomers with two chiral centres was investigated by kinetic method with trimeric metal‐bound complexes. Four enantiomeric pairs of β‐amino acids were studied: c__is‐(1__R,2__S__)‐, c__is‐(1__S,2__R__)‐, t__rans‐(1__R,2__R__)‐ and t__rans‐(1__S,2__S__)‐2‐aminocyclopentanecarboxylic acids (cyclopentane β‐amino acids), and c__is‐(1__R,2__S__)‐, c__is‐(1__S,2__R__)‐, trans‐(1__R__,2__R__)‐, and trans‐(1__S__,2__S__)‐2‐aminocyclohexanecarboxylic acids (cyclohexane β‐amino acids). The results showed that the choice of metal ion (Cu^2+^, Ni^2+^) and chiral reference compound (α‐ and β‐amino acids) had an effect on the enantioselectivity. Especially, aromaticity of the reference compound was noted to enhance the enantioselectivity. The fixed‐ligand kinetic method, a modification of the kinetic method, was then applied to the same β‐amino acids, with dipeptides used as fixed ligands. With this method, dipeptide containing an aromatic side chain enhanced the enantioselectivity. Copyright © 2009 John Wiley & Sons, Ltd.