Axially Chiral Shape-Persistent Encapsulating Agents

In this review is presented the results of investigations during the last two decades on molecular recognition processes, mainly chiral host–guest systems insofar as they deal with intermolecular recognition events. Attention is devoted to those systems involving chiral hosts whose chirality does not arise from the presence of a chiral center and that possess a defined cavity to accommodate guests. Thus, the scope of this short review is restricted to chiral containers in which size, shape, and functionality are critical aspects, while those examples involving chirality transfer processes are excluded. The systems covered are those with axial chirality, including helical chirality, in which the chirality, that can be inherent or induced by steric interactions, originates from the 3D helical array of substituents. More specifically, the focus is on both macrocycles that bear open cavities and molecular cages with more enclosed voids.1 Introduction2 Encapsulating Agents: Macrocycles3 Encapsulating Agents: Molecular Cages4 Conclusions