Enantioselective Construction of Quaternary Stereocenters

The stereoselective formation of C−C bonds is of great importance for the synthesis of enantiomerically pure natural products and pharmaceuticals. A broad repertoire of chiral auxiliaries, reagents, and catalysts can be utilized for the reliable generation of tertiary stereocenters. In contrast, the synthesis of organic compounds with quaternary stereocenters is a much more demanding and challenging task. Every enantioselective synthetic method can demonstrate its value through the generation of a fully substituted carbon center. In this Minireview examples of newer stoichiometric and catalytic methods are summarized which have proved their suitability for the enantioselective construction of quaternary stereocenters. The synthesis of optically active natural products and pharmaceuticals with quaternary stereocenters is a particular challenge. The potential of new stoichiometric and catalytic asymmetric reactions can be proved by their suitability for the enantioselective generation of such fully substituted carbon centers, such as, for example, in the compounds shown.