Copper-Mediated Conjugate Reduction of Prochiral Sulfones

Significance

The paper describes a mild method to generate synthetically useful compounds with a stereocenter in the β-position of a sulfone. The R groups in β -position can be aliphatic or aromatic (with EWG and EDG substituents). The reduction is carried out in a highly stereoselective fashion to generate the products in high yield and high selectivity. The sulfone group can be easily converted into other functional groups after reduction without erosion of the optical purity. For instance Julia-Kocienski olefination gives access to compounds with an allylic stereocenter. For a recent short review on copper-mediated conjugate reductions, see: S. Rendler, M. Oestreich Angew. Chem. 2007, 119, 504-510.