Access to fluorinated dienes through hydrofluorination of 2-En-4-ynoates†

Abstract

The hydrofluorination of enynoates has been developed for the synthesis of fluorinated dienoates. Using a pyridinium tetrafluoroborate salt that is easily prepared on large scale, this approach enabled the direct conversion of these substrates to fluorinated targets through a vinyl cation mediated process. This approach was applied to a range of aryl-substituted enynoates to deliver the (Z)-configured products with high levels of stereo- and regioselectivity. Mechanistic studies were conducted to provide insights into the stereochemical outcome and reaction efficiency under different reaction conditions.