The aim of this work was to synthesize and to study homogeneous models of the rhenium oxide on alumina metathesis catalyst. A series of aluminium complexes, (ArO)(2)Al-Y, has been synthesized, where ArO is a 4-substituted-2,6-di-tertbutylphenoxy ligand, or (ArO)(2) is a -CH2- or -S-ortho bridged-4,4'-di-tert-butyldiphenoxy ligand, and Y is an alkyl or chloride ligand. The reaction of (ArO)(2)Al-Cl with AgReO4 led to new complexes (ArO)(2)Al-OReO3 (A). These complexes exhibit a low activity in the metathesis of 2-pentene. Complexes (ArO)(2)Al-R (R = iBu, Et) react with Re2O7 in THF or dioxane, giving type B complexes including oligomeric linkages like O3Re-[Al(OAr)-O](2)-ReO3. They show a fairly high activity in the metathesis of 2-pentene, with TOF values as high as 100 min(-1). Complexes of type A may be converted into complexes of type B upon reaction with (ArO),Al-R in an ether solvent. The high activity of B complexes is tentatively related to the presence of Al-O-Al linkages that are known to induce a powerful bidentate Lewis acidity.