Crown ether complexes of sodium and potassium 2-(benzotriazol-2-yl)phenolates: Synthesis and catalysis towards the ring-opening polymerization of <i>rac</i>-lactide

2017-11-13T19:10:20Z (GMT) by Lu-Lu Tian Bing-Bing Wu Zhong-Xia Wang
<p>Crown ether complexes of sodium and potassium 2-(benzotriazol-2-yl)phenolates were synthesized and characterized. In the presence of BnOH these complexes are highly active catalysts for the controlled ring-opening polymerization of <i>rac</i>-lactide. The polymerizations are iso-selective and the <i>P</i><sub>m</sub> of polylactide reached 0.77 when the polymerization was performed in toluene at −60°C; whereas heterorich-polylactide was obtained when the polymerization was carried out in CH<sub>2</sub>Cl<sub>2</sub> or THF.</p>