Desymmetrization of meso-Diols via Enantioselective Silylation

Significance

A catalytic protocol for the desymmetrization of various meso-diols via monoprotection as silyl ethers is described. Cyclic as well as acyclic substrates containing hydroxyl groups in different structural settings have been employed. As chiral promoters, the authors used amino acid based small molecules developed in their group. These molecules act as bifunctional catalysts: both by H-bonding to ensure catalyst-substrate binding and by Lewis base activation of the silyl chloride reagent. A transition-state model is proposed based on a detailed investigation of the structure-activity relationship of modified catalyst candidates compared with the original catalyst structure.