Highly Stereocontrolled Ring‐Opening Polymerization of Racemic Alkyl β‐Malolactonates Mediated by Yttrium [Amino‐alkoxy‐bis(phenolate)] Complexes
作者:Cédric G. Jaffredo、Yulia Chapurina、Evgueni Kirillov、Jean‐François Carpentier、Sophie M. Guillaume
DOI:10.1002/chem.201600223
日期:2016.5.23
resulting polyesters. ROP promoted by catalysts with halogen (Cl, Br)‐disubstituted ligands allowed the first reported synthesis of highly syndiotactic PMLARs (Pr ≥ 0.95); conversely, catalysts bearing bulky alkyl and aryl ortho‐substituted ligands proved largely ineffective. All polymers have been characterized by 1H and 13C1H} NMR spectroscopy, MALDI‐ToF mass spectrometry and DSC analyses. Statistical
钇[氨基-烷氧基-双(酚盐)]酰胺基络合物已用于外消旋烷基β-丙二酸内酯(4-烷氧基羰基-2-氧杂环丁烷,rac - MLA R s)的开环聚合(ROP)。全部),苄基(Bz)或甲基(Me)侧酯官能团。金属辅助物中酚盐环上的邻位取代基的性质决定了ROP的立体控制,因此决定了所得聚酯的间规富集。ROP促进通过与卤素(氯,溴)催化剂二取代的配体允许高度间同立构PMLA的首次报道合成- [R S(P - [R ≥0.95); 相反,带有庞大烷基和芳基邻位基团的催化剂事实证明,预取代的配体无效。所有聚合物均已通过1 H和13 C 1 H} NMR光谱,MALDI-ToF质谱和DSC分析进行了表征。统计和热分析使链端控制机制合理化。聚合的立体控制遵循rac ‐MLA Bz和rac ‐MLA All的ROP的马尔可夫一阶(Mk1)模型,而rac ‐MLA Me的ROP遵循导致了马尔可夫二阶类型(M