Synthesis of Aluminum Complexes Bearing 8-Anilide-5,6,7-trihydroquinoline Ligands: Highly Active Catalyst Precursors for Ring-Opening Polymerization of Cyclic Esters.

The stoichiometric reactions of 8-(2,6-R¹-4-R²-anilide)-5,6,7-trihydroquinoline () with AlR₃ (R = Me or Et) afforded the aluminum complexes (⁻,: R¹ = Pr, R² = H, R = Me; : R¹ = Me, R² = H, R = Me; : R¹ = H, R² = H, R = Me; : R¹ = Me, R² = Me, R = Me; : R¹ = Me, R² = Me, R = Et) in high yields. All aluminum complexes were characterized by NMR spectroscopy and elemental analysis. The molecular structures of complexes and were determined by single-crystal X-ray diffractions and revealed a distorted tetrahedral geometry at aluminum. In the presence of BnOH, complexes ⁻ efficiently initiated the ring-opening homopolymerization of -caprolactone (-CL) and -lactide (-LA), respectively, in a living/controlled manner.