Direct Synthesis of Pentafluoroethyl Copper from Pentafluoropropionate as an Economical C₂F₅ Source: Application to Pentafluoroethylation of Arylboronic Acids and Aryl Bromides

The direct synthesis of penta­fluoro­ethyl copper (CuC₂F₅) from a cuprate reagent and ethyl penta­fluoro­propionate as one of the most economical and useful penta­fluoro­ethyl sources was accomplished. The advantages of this method are; all the reagents employed are low-cost and operationally simple, and the CuC₂F₅ reagent is prepared in virtually quantitative yield. Furthermore, the CuC₂F₅ reagent prepared was successfully applied to two types of penta­fluoro­ethylations with arylboronic acids and aryl bromides to provide the penta­fluoro­ethylated aromatic products in good-to-excellent yields, including large scale operations.