Photocatalytic four-component reaction to access covalent organic frameworks for photocatalysis

Photocatalytic four-component reaction is an efficient and environmentally friendly synthetic strategy known for its step economy and operational simplicity, enabling the preparation of diverse organic products. However, its application in synthesizing covalent organic frameworks (COFs) remains unexplored. Here, we report the rational synthesis of a class of functionalized COFs with high crystallinity and permanent porosity via the photocatalytic four-component reaction. This strategy not only addresses the long-standing challenge of harsh reaction conditions in conventional COFs synthesis methods, but also enables the integration of four different types of monomers in a one-pot process to create structurally diverse COFs. Furthermore, the resulting Cp-tBu-N₃-COF can function as an efficient photocatalyst for the visible-light-driven synthesis of benzimidazoles. This work provides a promising strategy to access COFs in a mild and sustainable way.