ETUDES SUR LE MECANISME DE LA METATHESE DES OLEFINES I. NATURE DES CATALYSEURS; NECESSITE D'HYDRURE DE TUNGSTENE

Article abstract of DOI:10.1016/S0022-328X(00)94424-3

The nature of the catalyst for olefin metathesis under homogeneous conditions was examined in the case of tungsten derivatives.With WCl6 as starting material for preparation of the catalyst, it was shown that only those chemicals which are able to transfer hydride to tungsten, were efficient cocatalysts.For starting materials derived from zerovalent tungsten, such as W(CO)6 or (arene)W(CO)3, it was shown that these were catalytically unefficient in aromatic solvents, unless they were activated by heat or traces of oxygen; indeed in some cases, traces of phenol were detected.Complex hydrides of tungsten(II) were active catalysts, but complex hydrides of tungsten(IV) were not.It was concluded that hydrides of tungsten(II) are probably involved in the catalysis of olefin metathesis.