Two Stepwise Synthetic Routes toward a Hetero[4]rotaxane

Heterorotaxanes have been emerging as an important class of Mechanically interlocked molecules and have attracted much attention in recent years., Driven by the distinguishable host guest, interactions between crown ether macrocycles and ammonium with different sizes, a novel hetero[4]rotaxane was successfully prepared by employing the combination of copper-catalyzed click reaction and P(n-Bu)(3)-catalyzed esterification reaction as stoppering reactions. The hetero,[4]rotaxane contains an interlocked species in which a dibenzo[24]crown-8 ring threaded by a dibenzylammonium-containing component With two benzo[21]crown-7 macrocycles at both ends, to act as stoppers, and each of the two benzo[21]crown-7 rings is also threaded with a benzylalkylammonium unit to form the second interlocked species. The hetero[4]rotaxane was prepared through two different stepwise synthetic routes, and the complicated chemical structure of the hetero[4]-rotaxane was well-characterized by H-1 NMR spectroscopy and high-resolution electrospray ionization. (HR-ESI) mass spectrometry. The investigation Shows that the construction of Complicated topological heterorotaxane can be achieved via distinct approaches with high efficiencies, which may, provide a foundation for the construction of more sophisticated heterorotaxane systems. or functional supermolecules.