Asymmetric Synthesis of α-Chloro-α-halo Ketones by Decarboxylative Chlorination of α-Halo-β-ketocarboxylic Acids

Chiral α-chloro-α-fluoro ketones were synthesized by enantio­selective decarboxylative chlorination of α-chloro-β-ketocarboxylic acids in the presence of a chiral amine catalyst. The reaction yielded the corresponding α-chloro-α-fluoro ketones with moderate-to-high enantioselectivity (up to 90% ee). The method was also applied to the synthesis of α-bromo-α-chloro ketones with 90% ee.