The molecules of IF and BrF as entities, prepared from the respective elements, have practically never been used in organic chemistry. When reacted with various types of alkynes the unknown family of compounds containing CF2CX2 (X = I, Br) was obtained in good yields. With phenylacetylenes an additional substitution of one or both X atoms by fluorine was observed. Very deactivated triple bonds, such as 23 and 25, react successfully only with BrF. Since the starting material is F2 and most reactions are fast, this method should be suitable for synthesis of biologically interesting 18F-containing compounds. The main method used previously for introducing the elements of XF into organic molecules, namely with N-halo amides-anhydrous HF, is not suitable for reaction with alkynes.