Magnesium complexes containing bis-amido-oxazolinate ligands as efficient catalysts for ring opening polymerisation of L-lactide

A series of magnesium bis(amido-oxazolinate) complexes have been described. Reactions of six amido-oxazolinate ligand precursors, HNC2MeOxa, HNC2OMeOxa, HNC2StBuOxa, HNPhOxa, HNPhOMeOxa or HNPhSMeOxa, with half molar equivalent of MgnBu2 in hexane yield the magnesium bis(amido-oxazolinate) complexes, (NC2EOxa)2Mg [C2E = propyl, (NC2MeOxa)2Mg (1); C2E = 2-methoxyethyl, (NC2OMeOxa)2Mg (2); C2E = 2-tert-butylthioethyl, (NC2StBuOxa)2Mg (3)], or magnesium bis(anilido-oxazolinate) complexes, (NArOxa)2Mg [Ar = phenyl, (NPhOxa)2Mg (4); Ar = 2-methoxyphenyl, (NPhOMeOxa)2Mg (5); Ar = 2-methylthiophenyl, (NPhSMeOxa)2Mg (6)], respectively. The molecular structures are reported for compounds 1, 2, 5 and 6. Their catalytic activities toward the ring opening polymerisation of L-lactide in the presence of benzyl alcohol are also under investigation.