Enantioselective recognition of chiral carboxylic acids by a β-amino acid and 1,10-phenanthroline based chiral fluorescent sensor

Abstract

A novel chiral 1,10-phenanthroline-based fluorescent sensor was designed and synthesized from optical active β-amino acids. It used 1,10-phenanthroline moiety as a fluorescent signaling site and binding site, with optically active β-amino acids as a chiral barrier site. Notably, the optically active β-amino acids were obtained by a Lewis base catalyzed hydrosilylation of β-enamino esters according to our former work. The chiral sensor has been used to conduct the enantioselective recognition of chiral mono and dicarboxylic acids derivatives. Using this fluorescent sensor, a moderate “turn-off” fluorescence-diminishment response towards enantiomer of tartaric acids, and proline was observed. It found that L-enantiomers quench the chiral fluorescence sensor more efficiently than D-enantiomers due to the absolute configuration of the β-amino acid.