Development of green and low-cost chiral oxidants for asymmetric catalytic hydroxylation of enals

A novel type of chiral oxidants are developed for efficient and enantioselective β-hydroxylation reaction of enals. The chiral oxidants can be easily obtained from readily available and inexpensive substituted benzoic acids and chiral prolinols. A commercially accessible and inexpensive achiral NHC catalyst is used for this catalytic approach. β-Hydroxyl esters bearing various substituents and substitution patterns are afforded as the final products in moderate to excellent yields and enantioselectivities. A new type of chiral oxidants are developed and successfully applied in the asymmetric β-hydroxylation of enals under the catalysis of an inexpensive achiral NHC catalyst. This type of chiral oxidants can be easily prepared from the low-cost starting materials of substituted benzoic acids and chiral prolinols through simple dehydrative amidation reactions. [Display omitted]