Direct Access to α,α-Difluoroacylated Arenes by Palladium-Catalyzed Carbonylation of (Hetero)Aryl Boronic Acid Derivatives

A palladium‐catalyzed carbonylative coupling of (hetero)aryl boronates or boronic acid salts with carbon monoxide and α‐bromo‐α,α‐difluoroamides and bromo‐α,α‐difluoroesters is described herein. The method is useful for the synthesis of a diverse selection of (hetero)aryl α,α‐difluoro‐β‐ketoamides and α,α‐difluoro‐β‐ketoesters, which are useful building blocks for the generation of functionalized difluoroacylated and difluoroalkyl arenes. The method could be further extended to a one‐pot protocol for the formation of difluoroacetophenones. Yielding to pressure: The title reaction produces aryl α,α‐difluoro‐β‐ketoamides and ‐esters from readily available difluorinated carboxylic acid derivatives by employing gaseous carbon monoxide. The method features low CO pressures and high functional‐group tolerance. The fluorinated products can be transformed into a variety fluoroalkylated structures.