Journal of the American Chemical Society, Vol.133, No.23, 8818-8821, 2011
Organocatalytic Asymmetric Halogenation/Semipinacol Rearrangement: Highly Efficient Synthesis of Chiral alpha-Oxa-Quaternary beta-Haloketones
A novel asymmetric halogenation/semipinacol rearrangement reaction catalyzed by cinchona alkaloid derivatives was developed. Two types of beta-haloketones (X = Br, Cl) were obtained with up to 95% yield and 99% enantiomeric excess. The desired (+) and (-) enantiomers of the beta-haloketones were readily obtained.