New routes to fluorinated acetylenes were developed on the basis of additions of iodofluorocarbons to silylacetylenes. Free radical addition of a, w-diiodoperfluoroalkanes to (trimethylsily1) acetylene gave the iodotrimethylsilyl olefins Me3SiIC= CH (CF2). CH= CISiMe3, which reacted with potassium tert-butoxide or DBU to give the (trimethylsily1) acetylenes and, with an excess of the base, the free diacetylenes. Perfluoroalkyl iodides ...