Alkali Carbonates Improve β,β-Diaryl Serine-Catalyzed Enantioselective α-Fluorination of β-Dicarbonyl Compounds

Abstract

Herein, we report the highly enantioselective α-fluorination of both cyclic and acyclic β-dicarbonyl compounds, including β-diketones, β-ketoesters, and β-ketoamides. The reactions with β,β-diaryl serines as primary amine organocatalysts were enhanced by adding alkali carbonates, such as Na2CO3 or Li2CO3, and enabled the reaction to be conducted with only 1.1 equiv of Selectfluor. The optimal conditions afforded the α-fluorinated β-dicarbonyl compounds in 50–99% yield with excellent enantioselectivity (up to 98% ee).