Aluminum(salen) Complexes as Catalysts for the Kinetic Resolution of Terminal Epoxides via CO2 Coupling

The development of inexpensive and sustainable aluminum­(salen) complexes as catalysts for the kinetic resolution of terminal epoxides is described. The kinetic resolution is carried out under mild conditions (0–25 °C and 1 bar of CO2 pressure) in the presence of tetrabutylammonium bromide as co-catalyst in the absence of solvent. The relative rate of reaction of the two epoxide enantiomers (krel) is substrate dependent, and the highest krel obtained was 15.4, using N-(2,3-epoxypropyl)­diphenylamine as substrate.