Carbamate triserine lactone receptors for anion recognition

We have taken advantage of the ability of the cyclic triester of l-serine to organize ligand units appended to the three α-amine functionalities, as in enterobactin, a siderophore produced by enteric bacteria that binds ferric ion exceptionally well (Kf = 1049). As an extension of the preorganization concept, this work describes the preparation and characterization of carbamate triserine lactone receptors 1–6 and their ability to act as molecular receptors for anions. These receptors bind halides (F− ≫ Cl− > Br− > I−) with binding constants K in the range 21–7350 L mol−1.