Asymmetric Oxidation of Sulfides to Sulfoxides Catalyzed by β-Cyclodextrin

Abstract

Cyclodextrins are naturally occurring doughnut-shaped molecules composed of 6,7 and 8 D-glucose units and are known to be able to form inclusion complexes with a wide variety of molecules.^1–3 Due to these properties cyclodextrins (CD) have been widely used as a model of enzymes because they form molecular complexes with substrates prior to chemical transformations. From the point of view of stereochemistry it is interesting to point out that cyclodextrins are chiral molecules and show enantioselection in many reactions. This feature has been utilized for the optical resolution of racemic compounds and in asymmetric synthesis, although the application of CDs as chiral catalysts or reagents for asymmetric synthesis has been limited to a small number of reactions as yet.₄