Zwitterion-Catalyzed Deacylative Dihalogenation of β-Oxo Amides.

α,α-Dihalo-N-arylacetamides are commonly used as intermediates in various organic reactions. In the study described here, a catalytic synthesis of α,α-dihalo-N-arylacetamides from β-oxo amides was developed using zwitterionic catalysts and N-halosuccinimides as the halogen sources. The corresponding α,α-dihalo-N-arylacetamides were obtained in good to excellent yields, and no aromatic halogenated side products were detected. The reaction conditions were mild, and no strong base or acid was required.