Dergiler / Turkish Journal of Chemistry / 2013 / Cilt: 37 - Sayı: 3
C2-Symmetric chiral diamine ligands for enantiomeric recognition of amino acid esters and mandelic acid by proton NMR titration method
- Sayfa
- 374–382
- DOI
- —
Özet
Two novel C2-symmetric chiral diamines containing a -phenylethyl and a -(1-naphthyl)ethyl chiral subunits were prepared with quantitative yields. Enantiomeric recognition properties of these simple structured diamine ligands towards D- and L-amino acid esters and D- and L-mandelic acid were examined by the 1H NMR titration method. These ligands exhibited strong complexation (with Kf up to 2481 M-1) and good enantioselectivity (up to KL/KD = 4.08) towards the mandelic acid enantiomers. The results show that simple structured and easily accessible acyclic C2-symmetrical compounds can also be used for enantiomeric recognition of racemic amino acids and mandelic acid in addition to complex molecules such as crown ethers and other cyclic molecules.
Abstract
Two novel C2-symmetric chiral diamines containing a -phenylethyl and a -(1-naphthyl)ethyl chiral subunits were prepared with quantitative yields. Enantiomeric recognition properties of these simple structured diamine ligands towards D- and L-amino acid esters and D- and L-mandelic acid were examined by the 1H NMR titration method. These ligands exhibited strong complexation (with Kf up to 2481 M-1) and good enantioselectivity (up to KL/KD = 4.08) towards the mandelic acid enantiomers. The results show that simple structured and easily accessible acyclic C2-symmetrical compounds can also be used for enantiomeric recognition of racemic amino acids and mandelic acid in addition to complex molecules such as crown ethers and other cyclic molecules.