An in-water' halogen-ion compatible click catalyst for cucurbituril guest ligation

Most of the cucurbituril (CB) guests are water soluble cationic compounds with halogen counter-ions. Here, an in-water' halogen-ion compatible copper catalysed azide-alkyne cycloaddition (CuAAC) catalyst, tris[1-(3-hyroxypropyl)-1H-1,2,3-triazol-4-yl]methanolCuCl (THPTMCuCl), was designed for CB guest ligation. The catalyst demonstrates not only high catalytic activity, but also compatibility to cationic substrates, halogen-ions and free amino groups. A CB[8]-based star pseudo[5]rotaxane and a CB[7]-based main-chain alternative polypseudorotaxane were constructed using THPTMCuCl, which further verified its applicability for the construction of CB-based supramolecular architectures.