Building a Co‐Salen‐Immobilized Porous Organic Polymer Catalyst for CO₂ Cycloaddition

The CO 2 ‐epoxide addition to cyclic carbonate is of great significance but usually requires high temperatures and CO 2 pressures. Herein, a spirobifluorene‐based porous organic polymer catalyst is designed with a Co‐salen complex immobilized on the backbone ( ST‐CoSalen‐POP ) to enable CO 2 fixation under mild conditions. ST‐CoSalen‐POP possesses a high Co‐loading content (9.35 wt%), a large pore volume, and high CO 2 adsorption capacity. This catalyst achieves a 96% yield in the cycloaddition of CO 2 with epoxides at 25 °C and 0.1 MPa CO 2 pressures. Moreover, ST‐CoSalen‐POP also offers the advantages of wide adaptability over epoxide substrates and high structural stability for three consecutive cycles. This study presents a novel catalytic approach for promoting CO 2 fixation, offering a significant advancement in the efficient synthesis of fine chemicals.