We report herein on the phosphine-catalyzed Z-selective carbofluorination of alkynoates bearing an N-heteroarene unit using acyl fluorides as bifunctional reagents. This reaction proceeds through pentacoordinate fluorophosphorane(V) intermediate, resulting in the formation of a C–F bond by a ligand coupling process. The Z-selectivity is attributed to the thermodynamic stabilization of a Z-isomer by orbital interactions between lone pair electrons of an N-heteroarene and the π* orbital of a carbonyl group.

We report herein the phosphine-catalyzed 1,2-diacylation of alkynes using acyl fluorides and acylsilanes as acyl sources. The key to the success of the reaction is a formal oxidative addition–ligand metathesis–reductive elimination cycle based on phosphine redox catalysis, which allows for the installation of two different acyl groups into an alkyne in a regioselective manner.