Aluminum complexes supported by tridentate aminophenoxide ligand as efficient catalysts for ring-opening polymerization of epsilon-caprolactone

Abstract

Aluminum complexes bearing dianionic amine bis(phenolate) ligand are described. Reactions of ligand precursors H2O2NMe or H2O2NPr [H2O2NMe = (CH3)N-(CH2-2-HO-3.5-C6H2(Bu-t)(2))(2); H2O2NPr = (CH3CH2CH2)N-(CH2-2-HO-3,5-C6H2(Bu-t)(2))2] with 1.1 mol equiv of AlMe3 in toluene afford MeAlO2-NMe) (1) and MeAI(O2NPr) (2) as four-coordinate aluminum methyl complexes. The molecular structures are reported for compounds 1 and 2. Both compounds show excellent catalytic activity toward the ring-opening polymerization of is an element of-caprolactone in the presence of benzyl alcohol.