Biguanide-functionalized hierarchical porous covalent organic frameworks for efficient catalysis of condensation reactions

Covalent organic frameworks (COFs) can be rationally designed with desired physicochemical properties for a far-ranging application in catalytic systems. Herein, a biguanide-functionalized covalent organic framework was designed and prepared via N-alkylation reaction, exhibiting a granular aggregate structure with high specific surface area. The biguanide-decorated DG–COF can be used as a highly efficient basic catalyst for the Knoevenagel condensation and Knoevenagel-Michael-cyclocondensation reaction. The present methodology is of excellent yields, short reaction times and simple operational procedure. DG–COF catalytic performance does not change after eight-times regeneration.