CuI-catalysed reactions between halide complexes of Fe, Mo, W or Pt an
d an excess of buta-1,3-diyne in the presence of diethylamine lead to
the formation of buta-1,3-diynyl compounds; elaboration of the diynyl
ligand is achieved by replacement of H by either non-metal or metal gr
oups, by coordination to the C=C triple bonds and by incorporation of
the terminal C atoms into clusters with consequent electronic rearrang
ement along the C-4 chain.