Conjugated Additions in Hydrogen Fluoride

Fluorine and another substituent can be added in a single step to compounds having CC double bonds in anhydrous hydrogen fluoride. It is possible in this way to obtain e.g. α-fluorinated β-halogeno, β-alkyl, β-nitro, and β-amino compounds, and also (in some cases by secondary reactions) fluorinated ethers, alcohols, esters, and carboxylic acids, β-fluoro alcohols can be obtained by conjugated “hypofluorination” in the presence of oxenium ions.