The Efficient CO2 Fixation Catalyzed by Fe-Based Catalyst for Synthesizing Benzimidazoles

As the main resource of greenhouse gas, CO 2 needs to be fixed into different chemicals to relieve the environmental problem. Fe-based catalyst and g-C 3 N 4 have received extensive attention due to their easy preparation, low cost, and environmental friendliness. Herein, a heterogeneous catalyst system consisting of rich-electron g-C 3 N 4 and strong electron-withdrawing groups Fe-complex [Fe(bpy)(CO) 2 (Cl) 2 ] was developed, which could promote electron transfer and enhance the electronic interaction for fixing CO 2 . o -phenylenediamine substrates with different electron-donating/withdrawing groups were employed to fix CO 2 into high-valued heterocycle benzimidazoles. The optimum reaction conditions were examined by orthogonal experiments. A series of benzimidazole derivatives were synthesized with yield up to 98%, which indicated the catalyst had the ability of fixing CO 2 . This catalyst provides a new pathway for fixing CO 2 into valuable benzimidazole derivatives. Graphical Abstract