AgBF4-catalyzed insertion of unactivated alkynes into C–F bonds of acyl fluorides

Abstract

We report an AgBF₄-catalyzed intermolecular C–F insertion of unactivated alkynes into acyl fluorides, providing a general route to monofluoroalkenes. This transformation enables both C–F bond cleavage and reformation without activated coupling partners, driven by cooperative Ag⁺/BF₄⁻ catalysis, where BF₄⁻ functions as a fluoride shuttle. The reaction exhibits broad substrate scope, accommodating aromatic and aliphatic acyl fluorides with high Z-selectivity. Given that monofluoroalkenes are valuable amide bioisosteres, this method enables direct access to bio-relevant motifs from carboxylic acid derivatives and supports late-stage monofluoroalkene installation in complex molecules.