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

Abstract

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.