Catalytic oligomerisation of butadiene using catalysts derived directly from metal atoms or di(η-arene)titanium compounds

The catalytic activity towards butadiene oligomerisation of zerovalent di(η-arene)titanium compounds has been explored under a variety of conditions. Co-condensations of metal atoms from the vapours of Ti, V, Cr, Mn, Fe, Co, or Ni with butadiene in benzene show that oligomerisation of butadiene is catalysed by all these metal atoms except titanium. Similar experiments, in which co-catalysts such as alkylaluminium halides or ligands such as tertiary phosphines are also present, have also been made. It is shown that the additional ligand or co-catalyst may change the nature of the oligomerisation product.