Chiral Octahedral Complexes of Cobalt(III) as Organic Catalysts in Disguise for the Asymmetric Addition of a Glycine Schiff Base Ester to Activated Olefins

Stereochemically inert and positively charged chiral complexes of cobalt(III) prepared from Schiff bases derived from chiral diamines and salicylaldehydes were shown to be efficient catalysts of the benchmark asymmetric phase-transfer Michael addition of nine activated olefins to O'Donnell's substrate. The reaction products had enantiomeric purities of up to 96%. DFT calculations were invoked to rationalize the stereochemistry of the addition.