Copper immobilized at a covalent organic framework: an efficient and recyclable heterogeneous catalyst for the Chan–Lam coupling reaction of aryl boronic acids and amines

Abstract

A covalent organic framework immobilized Cu catalyst was prepared and applied for synthesis of N-arylated products by Chan–Lam coupling reaction of arylboronic acids with various amines.

Abstract

A polyimide covalent organic framework (PI-COF) with high thermal and chemical stabilities has been readily prepared from commercially available and inexpensive reagents and was employed as an effective support for heterogeneous copper. It was demonstrated that the obtained Cu@PI-COF is a highly active heterogeneous catalyst which can effectively promote the Chan–Lam coupling reaction of aryl boronic acids and amines in an open flask without the aid of any base or additive. In addition, the catalyst could be readily recovered from the reaction mixture by simple filtration and reused for at least eight cycles without any observable change in structure and catalytic activity.