Planar chirale Metallocene
- Publisher: Publikationsserver der RWTH Aachen University
The element of planar chirality turned out to be of special importance to achieve high enantioselectivities in various asymmetric processes. In the course of this PhD thesis, the sulfoximine unit was established as a new chiral ortho-directing group for ferrocenes. By variation of the metal fragment and other structural properties of a published chiral ligand, a cyclopentadienylrhenium(I)tricarbonyl complex was identified as more selective than the original ferrocene system in the asymmetric phenyl transfer to aldehydes using zinc reagents. Also basing on the ferrocene scaffold, the first planar chiral, free, N-heterocyclic carbene was synthesized. Characterization was possible both in solution via NMR spectroscopy as well as ligand attached to different metal centers.