Enantioselective Synthesis of Planar-Chiral Transition-Metal Complexes by Homogeneous Olefi n-Metathesis Reactions and Their Application in Asymmetric Catalysis

rather classical methods. Indeed, examples of catalytic enantio-control of planar chirality in transition-metal complexes have been extremely rare, and this has been still a developing area in this fi eld. In this account, recent results from our research group on the catalytic asymmetric synthesis of various planar-chiral transition-metal complexes are outlined. The Mo-catalyzed asymmetric ring-closing metathesis has been found to be a powerful method to control the planar chirality in various transition-metal complexes such as ferrocenes, ruthenocenes, ( π -arene)chromium complexes, cymantrene derivatives, etc. Application of the highly enantiomerically enriched planar-chiral complexes in asymmetric synthesis has been also demonstrated.