Xylylene Clips for the Topology-Guided Control of the Inclusion and Self-Assembling Properties of Cyclodextrins

The topology of β-cyclodextrin can be molded, from toroidal to ovoid basket-shaped, by the installation of an o- or m-xylylene moiety connecting two consecutive d-glucopyranosyl units through the secondary O-2(I) and O-3(II) positions. This strategy can be exploited advantageously to precast the cavity for preferential inclusion of globular or planar guests as well as to privilege dimeric or monomeric species in water solution.