Bifunctional Chiral Catalyst far the Synthesis of Chiral Cyclic Carbonates from Carbon Dioxide and Epoxides

摘要

Bifunctional chiral catalysts incorporating the N,N'-bis(salicyli-dene)cyclohexenediaminato (salen) ligand and a quaternary onium salt within one metal complex were synthesized and developed for the catalytic kinetic resolution of racemic epox- ides with carbon dioxide to generate chiral cyclic carbonates in high yield and with moderate enantioselectivity. These new catalysts also have a great advantage as they can be recycled without any obvious loss of activity and enantioselectivity.