Asymmetric alpha-chlorination of beta-ketoesters using bifunctional ammonium salt catalysis

摘要

Chiral urea-quaternary ammonium salt hybrid organocatalysts were tested for their capability to control asymmetric alpha-chlorination reactions of beta-ketoesters. After a careful screening we identified a structurally simple catalyst derivative that allowed us to obtain enantiomeric ratios up to 90:10 under operationally simple conditions using just 1 mol% of the catalyst.