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

作者：Novacek Johanna^*; Monkowius Uwe; Himmel**ach Markus; Waser Mario^*

来源：Monatshefte fur Chemie, 2016, 147(3): 533-538.

DOI：10.1007/s00706-015-1604-7

• Organocatalysis
• Phase-transfer catalysis
• H-bonding activation
• Ion pairing

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.
[GRAPHICS]
.

• 出版日期2016-3