Perfluoro-n-heptylcopper(I) has been treated with 1-hexyne and 1-decyne to give 1-perfluoro-n-heptyl-1-hexene and-1-decene respectively. Reaction of the copper derivative with propargyl bromide and 3-hydroxy-3-methyl-1-butyne yielded 1-perfluoro-n-heptyl-1,2-propadiene and 1-perfluoroheptyl-3-methyl-1,2-butadiene respectively. Reactions of perfluoroalkylcopper(1) compounds CF3(CF2)nCu(n = 4—8) with