Synthesis and structural characterisation of zinc complexes bearing furanylmethyl and thiophenylmethyl derivatives of (R,R)-1,2-diaminocyclohexanes for stereoselective polymerisation of poly(rac-lactide)

Novel dichloro zinc complexes based on enantiopure N,N-diamine ligands bearing furanylmethyl and thiophenylmethyl pendent groups were synthesised, and their crystal structures were determined using X-ray crystallography. The isopropoxide derivatives (generated in situ) of these well-characterised complexes efficiently catalysed the ring-opening polymerisation (ROP) of rac-lactide (rac-LA) at two different temperatures under controlled conditions. Highly heterotactic polylactide (PLA) was obtained with Pr = 0.80 at −25 °C in THF.

Isopropoxy derivatives, generated in situ, of novel and well characterised dichloro zinc complexes bearing C2 symmetric N,N′-diamines with furanylmethyl and thiophenylmethyl pendent groups were assessed towards ROP of rac-LA and exhibited excellent activity. The polymerization proceeded in living manner yielded heterotactic PLA (Pr = 0.80) at −25 °C.Figure optionsDownload as PowerPoint slide