A novel type of catalysts for the asymmetric C-C bond formation based on chiral stereochemically inert cationic Coiii complexes

Schiff bases derived from (1 R ,2 R )-1,2-diaminocyclohexane and 1 eq. of salycylic (or substituted salycylic) aldehyde form stereochemically inert positively charged chiral octahedral Co iii complexes of Δ-configuration with the stereoselectivity approaching 100%. To evaluate the calatylic activity and stereoinduction of the resulting complexes with various counteranions in the outer sphere, a model reaction of trimethylsilyl cyanide addition to benzaldehyde was used. O -trimethylsilylmandelonitrile formed in the process had an enantiomeric purity up to 27%. Complexes with F − counterion showed high catalytic activity.