Multivalent Molecular Shuttles - Effect of Increasing the Number of Centers in Switchable Catalysts

A family of three molecular shuttles based upon ammonium/triazolinium salt motifs with one, two, and three catalytic centers were prepared along with their corresponding non-interlocked threads. The switching process for all rotaxanes was tested through an in situ procedure in solution. Furthermore, their organocatalysis of two Michale-type reactions by iminium activation was tested to check whether the increase of the number of catalytic centers in the same shuttle is a decisive factor to improve their efficiencies compared with those of single-active-site organocatalytic shuttles under the same conditions.