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.