syn-Fluoro- and -Oxy-trifluoromethylation of Arylacetylenes

One-step concurrent fluoro-trifluoromethylation across the triple bond of arylacetylenes in a syn mode is enabled by the collaboration of (phen)­Cu^III(CF₃)₃ and CsF that produces chemo-, regio-, and stereoselectively (Z)-α-fluoro-β-CF₃ styrenes. This method can be extended to achieve syn-oxy-trifluoromethylation and syn-aryl-trifluoromethylation of alkynes using phenoxides, alkoxides, or phenylboronic acid in place of CsF. It opens up new opportunities for preparing various functionalized trifluoromethylated Z-alkenes and demonstrates the potential of Cu­(III)–CF₃ complexes in organic synthesis.