Syntheses of metal diynyl complexes: Novel routes to all-carbon ligands

CuI-catalysed reactions between halide complexes of Fe, Mo, W or Pt and 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 groups, by coordination to the C=C triple bonds and by incorporation of the terminal C atoms into clusters with consequent electronic rearrangement along the C-4 chain.