SIMPLE CHIRAL CROWN ETHERS COMPLEXED WITH POTASSIUM TERT-BUTOXIDE AS EFFICIENT CATALYSTS FOR ASYMMETRIC MICHAEL ADDITIONS

Article abstract of DOI:10.1016/S0040-4039(01)93942-5

Simple C₂-symmetric chiral crown ether 1 complexed with KOtBu was found to work as an efficient chiral catalyst in Michael additions to cause high asymmetric induction.The results with various chiral crown ethers as catalysts suggest that diaxial-like conformation of the vicinal methyl groups of 1<*>potassium enolate complex is responsible for the chiral induction.