Tetracoordinate aluminum complexes bearing phenoxy-based ligands as catalysts for epoxide/anhydride copolymerization: some mechanistic insights

摘要: A series of dimethyl aluminum complexes the type [E,O]AlMe2 stabilized by phenoxy-imine, phenoxy-thioether and phenoxy-amine ligands have been tested as catalysts for ring-opening copolymerization epoxides anhydrides. All revealed to be active in cyclohexene oxide with succinic anhydride showing activities higher than pentacoordinate salen complexes. Interestingly, these limonene phthalic anhydride. moderate influence ligand structure on efficiency selectivity catalyst was also observed. Some mechanistic insights gained through NMR studies allowing identification a zwitterionic species formed initiating step polymerization reaction.