Aluminum Complexes Supported by Tridentate Aminophenoxide Ligand as Efficient Catalysts for Ring-Opening Polymerization of ε-Caprolactone

Abstract

Aluminum complexes bearing dianionic amine bis(phenolate) ligand are described. Reactions of ligand precursors H 2 O 2 NMe or H 2 O 2 NPr [H 2 O 2 NMe = (CH 3 )N-(CH 2 -2-HO-3,5-C 6 H 2 ( t Bu) 2 ) 2; H 2 O 2 NPr = (CH 3 CH 2 CH 2 )N-(CH 2 -2-HO-3,5-C 6 H 2 ( t Bu) 2 ) 2 ] with 1.1 mol equiv of AlMe 3 in toluene afford MeAl(O 2 NMe) ( 1 ) and MeAl(O 2 NPr) ( 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 ε-caprolactone in the presence of benzyl alcohol.