Stereochemistry of Lactide Polymerization with Chiral Catalysts: New Opportunities for Stereocontrol Using Polymer Exchange Mechanisms
作者:Tina M. Ovitt、Geoffrey W. Coates
DOI:10.1021/ja012052+
日期:2002.2.1
The synthesis of chiral aluminum and yttrium alkoxides and their application for lactide polymerization are reported. The complexes (SalBinap)MOR [4, M = Al, R = (i)Pr; 5, M = Y, R = (CH(2))(2)NMe(2)] are synthesized by reacting the ligand (SalBinap)H(2) [2,2'-[(1,1'-binaphthalene)-2,2'-diylbis(nitrilomethylidyne)]bisphenol] with the appropriate metal trisalkoxide. While enantiomerically pure yttrium
报道了手性铝和钇醇盐的合成及其在丙交酯聚合中的应用。配合物 (SalBinap)MOR [4, M = Al, R = (i)Pr; 5, M = Y, R = (CH(2))(2)NMe(2)] 通过配体 (SalBinap)H(2) [2,2'-[(1,1'-联萘)] 反应合成-2,2'-二基双(硝基亚甲基)]双酚]与适当的金属三醇盐。虽然对映体纯的钇配合物 5 在内消旋丙交酯或外消旋丙交酯的聚合中没有影响立体控制,但发现同手性 4 在一系列丙交酯聚合中表现出优异的立体控制。对映体纯 4 将内消旋丙交酯聚合成间规聚乳酸 (PLA),而 rac-4 将内消旋和外消旋丙交酯分别聚合成异同立构和等规立构嵌段 PLA。