Na2S2O4 initiated free radical additions of polyfluoroalkyl halides to 4-pentenamides

The free radical additions of fluorine-containing halides to 4-pentenamides initiated by Na2S2O4 were investigated. Both polyfluoroalkyl iodide and ethyl iododifluoroacetate, gave rise to fluorine-containing γ-butyrolactones as the main products while bromides such as ethyl bromodifluoroacetate gave the addition–reduction product. After steric and stereo effects on reaction yields were studied using various substrates, it was concluded that the reactions of 4-pentenamides and polyfluoroalkyl iodides provide one alternative approach to prepare γ-butyrolactones with fluorinated side chains.

Graphical abstractWe described the Na2S2O4 initiated free radical additions of fluoroalkyl halides to 4-pentenamides. For polyfluoroalkyl iodides and ethyl iododifluoroacetate, the reaction afforded fluorine-containing γ-butyrolactones as the main products, while reaction of ethyl bromodifluoroacetate only resulted in the addition-debromination product. Figure optionsDownload full-size imageDownload as PowerPoint slide