Foldamers with helical cavities for binding complementary guests

This tutorial review provides a summary of the binding of neutral molecules, cations and anions within helical cavities formed specifically by the folding of unnatural oligomers, called foldamers. Foldamers are emerging as a new class of synthetic receptors whose binding sites are not formed by preorganization of covalent bonds, but rather through the combination of various noncovalent interactions that induce folding and subsequent arrangement of functional groups within a helical cavity. The function of foldamers as synthetic receptors can be tuned by careful selection of modular building blocks displaying the appropriate functionality required for guest complexation. As the molecular toolbox expands to create well-defined helical structures, new and interesting functions emerge. It is the purpose of this review to provide the reader with an introduction to helical cavities formed specifically by foldamers and their subsequent function as molecular and ionic receptors. It will interest the supramolecular, organic and bioorganic communities.