Ni(II)-PPP Complexes: From the Hydroamination of Activated Olefins to the Synthesis of ?-Amino Acids

Abstract

Complexes of the type [Ni(PPP)(solvent)]X2 containing ferrocenyl tridentate ligands have been prepared and used as catalysts in the asymmetric hydroamination of activated olefins (i.e. bearing an electron-withdrawing group). In the case of acrylonitrile derivatives the addition of aliphatic amines displayed relatively high activities and moderate enantioselectivity (yields up to 99%, ee's up to 69%). The reactions were also carried out in various ionic liquids (imidazolium and picolinium salts) with results comparable to those obtained in common organic solvents. Additionally, we describe the conversion of several products to ?-amino acid derivatives.

Keywords

• Activated olefins
• Beta-amino acids
• Asymmetric catalysis
• Hydroamination
• Nickel