Transition Metal-Free Incorporation of CO2

Abstract

Carbon dioxide can be regarded as an ideal C 1 chemical feedstock in both academic and pharmaceutical laboratories owing to its abundance, low cost, non-toxicity, and nonflammability. However, due to CO 2 inherent thermodynamic stability and kinetic inertness, it is difficult to convert CO 2 to value-added chemicals under mild conditions. In order to overcome such barriers, numerous useful synthetic methodologies by strategically using highly active catalysts have been developed for the incorporation of CO 2 to organic compounds. Transition metal-free compounds are proved to be promising efficacious catalysts able to activate CO 2 molecule for efficient transformation of CO 2 on the basis of mechanistic understanding at the molecular level. This chapter features recent advances at methodologies for catalytic transformation of CO 2 promoted by organocatalysts (e.g., N-heterocyclic carbenes, frustrated Lewis pairs and superbases), ionic liquids, and main group metal to produce value-added chemicals such as linear or cyclic carbonates, quinazoline-2,4(1H,3H )-diones, alkylidene cyclic carbonates, amino acids, and so on.