Acridine‐Functionalized Covalent Organic Frameworks (COFs) as Photocatalysts for Metallaphotocatalytic C−N Cross‐Coupling

Covalent organic frameworks (COFs) are highly customizable, porous, and crystalline polymers formed by linking small organic building blocks through covalent bonds. We synthesized a new series of COFs using an acridine linker and benzene-1,3,5-tricarbaldehyde derivatives with varying hydroxy groups, creating materials with broad visible light absorption. These COFs functioned as photocatalysts in metallaphotocatalytic C−N cross-coupling reactions. The β-ketoenamine-linked COF exhibited superior activity due to enhanced charge separation upon light irradiation. It demonstrated high yields for several aryl bromides, good recyclability, and effective catalysis under green light.