Pinar Deniz, Y. Turgut, M. Toǧrul
Aug 26, 2011
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0
Influential Citations
13
Citations
Journal
Tetrahedron
Abstract
Abstract Four novel C 2 -symmetric enantiomerically pure, chiral pyridine-18-crown-6 type macrocycles containing lipophilic chains at the stereogenic centers were prepared. The enantioselectivity of the new ligands toward the enantiomers of d -, l -amino acid methyl ester derivatives were also determined by 1 H NMR titration method. These novel macrocycles have been showed to be strong complexing agents for d - and l -amino acid methyl ester hydrochloride salts (with K ass up to 13590 M −1 and ∆ G 0 up to 23.3 kJ mol −1 and selectivity ratio: 80:20) by 1 H NMR titration methods. These macrocyclic hosts exhibited enantioselective binding towards the d -enantiomer of valine methyl ester hydrochloride with K d / K l up to 5.08 in CDCl 3 with 0.25% CD 3 OD.