Supramolecular Catalyst Functions in Catalytic Amount: Cucurbit[7]uril Accelerates Click Reaction in Water

Abstract Macrocycles have garnered significant interest for their potential utility as supramolecular catalysts in modulating chemical transformations. Here, we report a reusable supramolecular catalytic system to accelerate copper(I) catalyzed Click cycloaddition (CuAAC) reactions in water. Our system comprises of 5 mol % CuI and 0.5 mol % of the supramolecular co‐catalyst, cucurbit[7]uril (CB7), which stabilizes and prevents the oxidation of Cu I . This catalysis can be cycled is that the triazole product or alkyne reactant hardly bind in the cavity of CB7 while there is an interaction between azide reactant and CB7 through molecular recognition. The dual catalysts can be facilely separated from the reaction system. As a result, the catalyst system can be recycled and reused for more than 10 consecutive cycles while maintaining high catalytic activity.