Highly Efficient Non‐Palladium‐Catalyzed Homocoupling of Arylboronic Acids Using a New Copper‐Coordinated Covalent Organic Framework

The formation of carbon–carbon bonds is essential in organic synthesis, making the development of new catalysts for CC bond formation a demanding task. Functionalization with specific structures in covalent organic frameworks (COFs) imparts them with unique properties. Their highly ordered pores, large surface area, and naturally low density make COFs excellent components of heterogeneous catalysts. When combined with transition metals, they deliver outstanding catalytic performance in organic reactions. In this study, we designed and synthesized a new COF, BTT‐BD(OH) 2 , which contains benzo[1,2‐b:3,4‐b′:5,6‐b″]trithiophene (BTT) and phenol hydroxyl groups derived from 4,4′‐diaminobiphenyl‐3,3′‐diol (BD(OH) 2 ), with a transition metal copper complexed to serve as a heterogeneous catalyst, Cu@COF. Here, we report on the catalysis of the synthesis of sp 2 ‐sp 2 linkages from arylboronic acids. The catalytic performance evaluation shows that the C–C coupling reaction catalyzed by Cu@COF proceeds smoothly under mild, environmentally friendly conditions (at room temperature, in methanol solvent, without alkali, in open air). A variety of symmetrical biaryl compounds has been successfully synthesized. The Cu@COF demonstrated high catalytic activity, broad substrate applicability, and good recyclability.