On some general regularities in the action of enantioselective hydrogenation catalysts

Abstract

Experiments on the asymmetric hydrogenation of prochiral keto compounds through intermediate catalysts-ligand-substrate triple complexes are summarized. Correlations of enantioselectivity of reaction on heterogeneous metallic catalysts modified with optically active amino acids are emphasized. Relationships of the stability constants of complexes corresponding to catalytic intermediates, to the optical yield in hydrogenation of ethyl acetoacetate and acetylacetone on Ni, Cu, and Co catalysts modified with ( S)-phenylalanine, ( S)-triptophane, and ( S)-tyrosine are reviewed. Correlations between enantioselectivity and chiral properties (magneto-optical rotatory dispersion and circular dichroism) of complexes are established. These provide a basis for the future selection of asymmetric metal catalysts for hydrogenation of prochiral keto compounds.