Asymmetric cyclopalladation of 1′-dimethylamino-[3] ferrocenophane: central and planar chirality and the effect of conformational rigidity

Abstract

1′-Dimethylamino[3]ferrocenophane undergoes asymmetric cyclopalladation in the presence of the sodium salt of N-acetyl- D- or - L-leucine to give an optically active organopalladium derivative in nearly quantitative yield. Due to the restriction of the conformational mobility of the bridged molecule, the S-configuration of the chiral centre induces preferentially S p planar chirality. An enantiomeric excess of 84.0% was achieved when 0.5 equivalent of Na 2PdCl 4 was used with the simultaneous kinetic resolution of amine, affording nearly 50% of enantiomeric purity.