Diamidoamine Aluminum Complexes: Synthesis, Structure, L–Lactide and ϵ‐Caprolactone Polymerization

A series of methyl and chlorido aluminum complexes decorated with diamidoamine ligands with different number of carbon atoms in the alkyl chains were prepared via methane elimination, salt methatesis route, transmetallation strategy or chlorination. They were investigated by various methods including 19F, 27Al NMR spectroscopy and showed to be active catalysts of ring‐opening polymerization of ϵ‐Cl and L−La. A new class of aluminum complexes based on pentafluorophenyl amido ligands has been prepared via reaction of free ligands with AlMe3. The intermediate formation of dimethyl aluminum complexes took place. Monomethyl aluminum complexes can be also prepared by reaction of tetrylenes and Me3Al. The reaction of methyl aluminum complexes with chlorinating agents were studied. Aluminum complexes were characterized by means of 1H, 13C and 19F NMR spectroscopy and used as catalysts in the ring‐opening polymerization of cyclic esters.