Highly active dinuclear cobalt complexes for solvent-free cycloaddition of CO

Dinuclear Co-based catalysts are used for the coupling reaction of epoxides and CO2 in the presence of a cocatalyst. The easily recyclable catalysts efficiently complete the coupling of CO2 with various epoxides into industrially important cyclic carbonates at low catalyst loading and displayed high catalytic activity under relatively low CO2 pressure and solvent-free conditions. The maximum TON (168 600) and TOF (3333 h-1) obtained in this work are the highest among the reported Co-complexes.