Ca2+-induced folding of a chiral ditopic receptor based on a Pybox ligand and enhancement of anion recognition

Abstract

A chiral Pybox ligand bearing two urea units was developed for a Ca²⁺-induced folding ligand. 1 ∶ 1 Ca²⁺ complexation of the Pybox ligand afforded chiral foldamer formation with coordination of the urea carbonyls to Ca²⁺. The halide-ion affinity of the foldamer was enhanced compared to Ca²⁺-free Pybox ligands.