Insertion of Carbenoids into CpH Bonds of Ferrocenes: An Enantioselective‐Catalytic Entry to Planar‐Chiral Ferrocenes

Not only significant enantioselectivities, but also chemical yields that are clearly higher than with achiral catalysts are seen for the asymmetric variant of the transition metal catalyzed cyclization of diazoketones such as 1. The carbene chemistry known for the functionalization of benzene derivatives has now been transferred to ferrocene for the first time.