Aluminum Aryloxide Compounds as Very Active Catalysts for Glycidyl Methacrylate Selective Ring-Opening Polymerization

New aluminum compounds of the type [AlXMe(OAr)](n) [X=Me (1), Cl (2)] bearing the bulky ligand OAr=2,6-bis(diphenylmethyl)-4-tert-butylphenoxide were synthesized and characterized in the solid state and in solution. These compounds are mononuclear in solution. Their catalytic activity in glycidyl methacrylate (GMA) polymerization was explored. This monomer contains two different functionalities, oxirane and methacrylate, and, hence, could give functionalized polymers by ring-opening polymerization (ROP) or vinyl polymerization. Catalysts 1 and 2 could selectively polymerize the oxirane functionality in minutes at room temperature, leaving the methacrylate group intact. Remarkably, 1 and 2 are the most active catalysts in ROP processes of GMA described so far.