Direct Photocatalytic Trifluoromethyl-Carboxylation of Enamides: A Gateway to α-Trifluoroethyl Phenylglycines

Abstract Incorporation of the trifluoromethyl (CF₃) groups is a well-established tactic to improve pharmacokinetic properties—metabolic stability, lipophilicity, and bioavailability—of bioactive molecules, including amino acids. Here we report a visible-light photocatalytic method for the direct trifluoromethyl carboxylation of enamides using sodium trifluoromethanesulfinate (CF₃SO₂Na) and CO₂, catalyzed by [Ir(ppy)₂(dtbbpy)](PF6). The reaction proceeds via a radical pathway and enables concurrent installation of CF₃ and carboxyl groups in a single step to furnish α-trifluoroethylated arylglycines. The protocol shows broad functional-group tolerance, accommodating halogen, alkyl, trifluoromethyl, and acetamido substituents on aryl enamides. This strategy provides streamlined access to CF₃-containing amino acid motifs relevant to medicinal chemistry and materials science.