Synthesis, characterization of aluminum complexes and the application in ring-opening polymerization of l-lactide

Aluminum complexes supported by a sulfonamide/Shiff base ligand are described. Reaction of AlMe3 with 1 equiv of ligand 1, gives methyl aluminum complex 2, and aluminum complex 3 is prepared by the reaction of complex 2 with 1 equiv of benzyl alcohol. Experimental results show that complex 3 is an efficient initiator for the ring-opening polymerization of lactide in controlled fashion, yielding polymers with expectative molecular weight and low polydispersity indexes. Furthermore, the complex 3 has isotactic selectivity for the ring-opening polymerization of rac-lactide.