Transition metal carbonyl clusters with ene–yne ligands

Ene–yne molecules are found as natural products. Natural and synthetic ene–ynes are actively studied and partly used as anticancer drugs. Conjugated and non-conjugated ene–yne molecules are widely used as synthons in organic reactions promoted by organometallic compounds. Surprisingly, the coordination of ene–ynes to transition metal clusters has not been fully rationalized up to now; the same happens for the (not very many) examples of their reactivity and of their potentials uses. In this paper the synthetic routes leading to (and the structures of) transition metal clusters containing ene–yne ligands are described. Comparisons with the chemistry of di-ynes coordinated to transition metal clusters are made.