CRC 858 A03 - Reversible Stabilization of Silicon-Stereogenic Silylium Ions in Enantioselective Lewis Acid Catalysis

Basic data for this project

Description

The major challenge of project A3 is the generation of a trivalent, cationic silicon compound (silylium ion) with its LUMO stabilized by a neighboring electron rich transition metal center. The interaction of the silicon atom and the transition metal leads to pyramidalization of the usually planar silicon cation. As a consequence, the silicon atom becomes stereogenic when provided with a specific substitution pattern. On the one hand these novel asymmetric substituted silylium ions shall be exploited as chiral Lewis acid catalysts, on the other hand they shall be utilized in (stoichiometric) enantioselective and desymmetrizing C(sp3)-F-bond activation reactions. The cooperative and essentially reversible interaction between transition metal and the strongly Lewis acidic silicon atom therefore is essential for a successful reaction outcome.