An Anion-Switchable Dual-Function Rotaxane Catalyst.

In situ switching of the associated anions of a rotaxane catalyst between Cl- and TFPB- exposes its dialkylammonium and imidazolium stations, respectively, thereby selectively catalyzing the reactions of a mixture of trans-cinnamaldehyde and an aliphatic thiol to yield the Michael adduct and the thioacetal product, respectively.

Dual-Way-Switchable Ester Rotaxanes Constructed Using the Recognition of Malonate Diesters.

Malonate diesters can thread into the cavity of a di(ethylene glycol)-containing macrocycle under the templating effect of a Na+ ion; the corresponding rotaxanes can be synthesized with good efficiency by applying several stoppering reactions. A molecular switch, in which the interlocked macrocycle was moved between two rarely used stations (i.e., malonate and TAA) through the addition of acid/base and the presence/absence of Na+ ions, was constructed using this new recognition system.