Recent advances in the synthesis of cyclic carbonates via CO2 cycloaddition to epoxides

Global concerns about high CO2 levels and dwindling supplies of fossil resources are increasing. The utilization of CO2 and waste biomass as renewable resources for valuable products is highly desirable to make various supply chains ‘greener’. Synthesis of cyclic carbonate from epoxide and CO2 is a highly promising reaction due to its 100% atom economy. Organic cyclic carbonates have a broad range of applications, such as high boiling point green polar aprotic solvents, electrolytes in Li-ion batteries, the monomer for polycarbonates and polyurethanes synthesis, intermediates for the manufacturing of pharmaceuticals and many other fine chemicals. Over the last 20 years significant progress has been made in this field of research. This review covers the recent developments in catalytic systems for the above-mentioned reaction that includes kinetics, mechanistic investigations and highlights the parameters affecting their activity and selectivity. Moreover, the recent efforts on the utilization of renewable resources as potential raw materials for the cyclic carbonate synthesis have also been discussed. Nonetheless, to satisfy the demands of a multi-scale approach for industrial transformation, the use of flow chemistry and novel reactor designs for the synthesis of cyclic carbonates has been also discussed.