Coordination complexes as catalysts for the coupling reactions of oxiranes and carbon dioxide

•Metal Coordination complexes as catalysts for the selective coupling of CO2 and epoxides to polycarbonates are reviewed.•Various current applications of several of these functionalized copolymers are discussed.•Synthesis and mechanistic studies of dimetallic coordination complexes are described, including synergistic effects between the two metals in enhancing catalytic activity.•Some comparisons of the roles of metal coordination complexes in the design of organocatalysts are provided.