Asymmetric olefination of metallic arene or diene complexes to form planarchiral complexes

The chiral phosphonoacetate (S)-1 can discriminate between the enantiotopic dicarbonyls of eta(6)-arene Cr and eta(4)-diene Fe complexes to afford opt ically active olefins with planar chirality in high enantiomeric excess and good yield. An analogous reagent (S)-2 was used for kinetic resolution of a racemic mixture of the aldehyde of the Fe eta(4)-diene, which resulted in formation of the corresponding olefin together with the recovered aldehyde in high enantiomeric excess. The absolute stereostructures of these adduct s were determined by X-ray analysis with anomalous dispersion of metals. (C ) 1999 Elsevier Science Ltd. All rights reserved.