Triethylborane Induced Perfluoroalkylation of Silyl Enol Ethers and Ketene Silyl Acetals with Perfluoroalkyl Iodides

Reaction of perfluoroalkyl iodides with silyl enol ethers mediated by Et3B in the presence of base such as 2,6-dimethylpyridine provides mixtures of perfluoroalkylated trialkylsilyl enol ethers and α-perfluoroalkylated ketones. The yield and distribution of the products heavily depend on the nature of base employed. Treatment of a reaction mixture consisting of perfluoroalkylated silyl enol ether and α-perfluoroalkylated ketone with coned HCl in THF gives α-perfluoroalkylated ketone as a single product. Reaction of ketene silyl acetals with perfluoroalkyl iodides in the absence of base affords α-perfluoroalkylated esters in excellent yields.