Three novel chiral zinc porphyrins (4a-4c) with protected chiral amino acid
substituents as chiral sources were synthesized. Their chiral recognition
of amino acid methyl esters was investigated using UV-vis spectrophotometri
c titration. Some enantioselectivities obtained are higher than that of the
known system, and the highest achieved in our study is 21.54 using host 4a
with PheOCH(3) as guest. We also show that higher enantioselectivity can b
e obtained at lower temperature. Circular dichroism spectra of chiral porph
yrin derivatives binding to enantiomers of guests show great shape and inte
nsity differences. Molecular modeling was performed to understand chiral re
cognition on a molecular level, and the results are in good agreement with
the experimental data.