Homo- and heteroleptic zinc aminophenolates as initiators for lactide polymerization.

The reaction of ZnEt2 with one or two equivalents of aminophenolate ligand N-[methyl(2-hydroxy-3,5-di-tert-butylphenyl)]-N-methyl-N-cyclohexylamine gives hetero- and homoleptic molecular compounds [(micro,eta2-L2)ZnEt]2 and [Zn(eta2-L2)2]. The later is most probably a mixture of diastereoisomers that in solution shows an interesting dynamic behaviour. Both complexes as well as the BnOH derivative of the latter, [(eta2-L2)Zn(micro-BnO)]2, proved excellent initiators for lactide polymerization.