A convergent strategy for the synthesis of beta-cyclodextrin analogues is reported, utilizing preferential cyclodimerization of an azido-alkyne trisaccharide via Cu(I)-catalyzed [3 + 2] dipolar cycloaddition of the alkyne and azide functional groups. The resultant oligosaccharide macrocycle retains the binding propensity of cyclodextrins, as demonstrated by the similar ANS association constants measured for macrocycle 1 and beta-cyclodextrin. This new synthetic strategy opens up new avenues for modular preparation of functionally diverse cyclodextrin analogues that are otherwise inaccessible.

No abstract

Negative beats positive: A channel composed of oligoether chains attached by amine groups to β‐cyclodextrin mediates the transport of halides across a phospholipid bilayer (see scheme) at faster rates than those observed for monovalent cations. Protonation of the amine linkages likely explains the preferential anion transport.

A gated synthetic ion channel with beta-cyclodextrin as the pore and azobenzene as the gate is reported. Irradiation converts a tethered trans-azobenzene to cis-azobenzene which likely transforms the channel from a self-inclusion complex to a dissociated structure. This transformation results in an increase in anion transport and a decrease in cation transport across a phospholipid vesicle membrane.

[structure: see text] A highly convergent strategy for the synthesis of C3- or C2-symmetric oligosaccharide macrocycles is reported. Molecular modeling indicates these macrocycles possess sterically congested cavities. Weak host-guest interactions are observed that should be beneficial for applications such as functionalized molecular pores.