Activation of the Re 2O 7/Al 2O 3 metathesis catalyst by aryloxyaluminium complexes

Abstract

Bis-aryloxyalkylaluminium complexes, previously involved in the synthesis of aryloxyaluminium perrhenate complexes that are active in olefin metathesis in homogeneous phase, are able to increase the activity of the supported Re 2O 7/Al 2O 3 metathesis catalyst. They are also able to make active an otherwise inactive low temperature-treated Re 2O 7/Al 2O 3 catalyst. They can be used to regenerate, for the first time at room temperature, a previously deactivated catalyst. Until now, a high temperature calcination treatment was essential for the regeneration. These properties are attributed to the strong Lewis acidic character of these aluminium complexes due to the low coordination state of the aluminium, protected by the aryloxy ligands.