Isotactic rac-Lactide Polymerization with Copper Complexes: The Influence of Complex Nuclearity.

Angew Chem Int Ed Engl

Centre in Green Chemistry and Catalysis, University of Montreal, Department of Chemistry, C. P. 6128 Succ. Centre-Ville, Montréal, QC, H3C 3J7 (Canada).

Published: November 2015

Diiminopyrrolide copper alkoxide complexes, LCuOR (OR(1)=N,N-dimethylamino ethoxide, OR(2)=2-pyridyl methoxide), are active for the polymerization of rac-lactide at ambient temperature in benzene to yield polymers with M(w)/M(n)=1.0-1.2. X-ray diffraction studies showed bridged dinuclear complexes in the solid state for both complexes. While LCuOR(1) provided only atactic polylactide, LCuOR(2) produced partially isotactic polylactide (P(m)=0.7). The difference in stereocontrol is attributed to a dinuclear active species for LCuOR(2) in contrast to a mononuclear species for LCuOR(1).

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http://dx.doi.org/10.1002/anie.201505674DOI Listing

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