Well‐Defined Aminophenolate Zinc and Magnesium Complexes as Excellent Inhitiators for the ROP of Lactides

A series of molecular homo and heteroleptic zinc and magnesium compounds with aminophenolate ligands [(µ,η 2 ‐L 2 )ZnEt] 2 ( 1 ), [(η 2 ‐L 2 )Zn(µ‐BnO)] 2 ( 2 ), [Zn(η 2 ‐L 2 ) 2 ] ( 3 ), [Zn(η 2 ‐L 3 ) 2 ] ( 4 ), [Mg(η 2 ‐L 3 ) 2 ] ( 5 ) (L 2 ‐H =  N ‐[methylene(2‐hydroxy‐3,5‐di‐ tert ‐butylphenyl)]‐ N ‐methyl‐ N ‐cyclohexylamine, L 3 ‐H =  N ‐[methylene(2‐hydroxy‐3,5‐di‐ tert ‐butylphenyl)]‐ N ‐methyl‐ N ‐methyl‐1,3‐dioxolaneamine) have been prepared and characterized. The homoleptic complexes 3–5 are most probably a mixture of diastereoisomers that in solution show an interesting dynamics which plays an important role in their catalytic behavior. The complexes 2 – 5 are efficient initiators in ring‐opening polymerization (ROP) of lactides to produce polymers with desired molecular weight and narrow polydispersity.