Zinc anilido-oxazolinate complexes as initiators for ring opening polymerization

Abstract

Three new anilido-oxazolines, ortho-C₆H₄(NHAr′)(4,4-dimethyl-2-oxazoline) [Ar′ = 2,4,6-trimethylphenyl, HNPh^TriMeOxa (1); 2,6-diisopropylphenyl, HNPh^DiiPrOxa (2); 2-methoxyphenyl, HNPh^OMeOxa (3)], have been prepared. Reactions of 1 or 2 with one molar equivalent of ZnEt₂ in tetrahydrofuran or hexane solution give the zinc ethyl complexes (NPh^TriMeOxa)ZnEt (4) and (NPh^DiiPrOxa)ZnEt (5). The dinuclear zinc benzyloxide complexes, [(NAr′Oxa)Zn(µ-OBn)]₂, [Ar′ = 2,4,6-trimethylphenyl, (6); 2-methoxyphenyl, (7)], were synthesized by the reaction of 4 with one molar equivalent of benzyl alcohol in tetrahydrofuran solution (for 6) or by treatment of 3 with one molar equivalent of ZnEt₂ in tetrahydrofuran solution followed by the addition of one molar equivalent of benzyl alcohol (for 7). The molecular structures are reported for compounds 6 and 7. Their catalytic activities toward the ring opening polymerization reactions are under investigation.