A series of new chiral bifunctional ionic liquid catalysts incorporating the N,N′-bis(salicyclidene)cyclohexene diaminatocobalt and an imidazolium salt in one molecule were designed and synthesized.
A kinetic resolution of racemic epoxides with carbon dioxide to generate chiral cyclic carbonates was achieved in high yield with reasonable enantioselectivity.
The effects of anixal anion, counterions and the chain length of alkyl of catalysts in these asymmetric cycloadditions were discussed.