Highly Enantioselective Copper-Catalyzed Electrophilic Trifluoromethylation of β-Ketoesters

Enantioselective Cu-catalyzed trifluoromethylation of beta-ketoesters using commercially available trifluoromethylating reagents is reported. A number of alpha-CF3 beta-ketoesters are obtained with up to 99% ee. The trifluoromethylated products were then transformed diastereoselectively to alpha-CF3 beta-hydroxyesters with two adjacent quaternary stereocenters via a Grignard reaction.