Desymmetrization-Oriented Enantioselective Synthesis of Silicon-Stereogenic Silanes by Palladium-Catalyzed C-H Olefinations.

A palladium-catalyzed chelation-assisted enantioselective C-H olefination of symmetrically diaryl-substituted tetraorganosilicon derivatives was developed, enabling the generation of nitrogen-containing silicon-stereogenic tetraorganosilicon compounds with modest to good yields and good to excellent enantioselectivities (up to 95.5:4.5 e.r.). The Thorpe-Ingold effect exerted by the substituents on silicon was observed to have a profound influence on formation of olefinated products which were further converted into other relevant chiral organosilanes without the loss of enantiomeric purity, thus demonstrating the synthetic utility of the developed enantioselective olefination.