Regio- and Enantioselective Macrocyclization from Dynamic Imine Formation: Chemo- and Enantioselective Fluorescent Recognition of Lysine.

The dynamic covalent chemistry of imines is utilized to conduct a regioselective as well as enantioselective synthesis of an unsymmetric ( C 1 ) chiral macrocycle from the reaction of an unsymmetric ( C 1 ) chiral dialdehyde, ( S )- 4 , that contains a salicylaldehyde unit and a benzaldehyde unit, with lysine, an unsymmetric ( C 1 ) chiral diamine. The enantioselectivity is further enhanced in the presence of Zn 2+ . Compound ( S )- 4 in combination with Zn 2+ is found to be a highly chemoselective as well as enantioselective fluorescent probe for lysine. It can be used to detect specific enantiomers of this amino acid.