Zeo-Click Chemistry: Copper(I)-Zeolite-Catalyzed Cascade Reaction; One-Pot Epoxide Ring-Opening and Cycloaddition

Copper(I)-modified zeolites, especially Cu-I-USY, proved to be very efficient catalysts in multi-component reactions of epoxides with sodium azide and terminal alkynes. Such catalysts allow highly regio- and stereoselective syntheses of hydroxymethylated triazoles. These heterogeneous, modified zeolites can easily be recovered and reused. Moreover, the cascade reaction was best performed in water at room temperature, rendering all the processes truly green. Detailed investigations revealed the role the Cu-I-modified zeolites play both during the epoxide ring-opening and cycloaddition steps.