Supramolecular Formation Induced by Recogonization of Stereoregularity in Cyclick Polymer

研究发现2-(卤代甲基)丙烯酸酯可以定量终止甲基丙烯酸甲酯(MMA)的立体有择阴离子聚合，得到末端具有反应性碳-碳双键的全同立构和间规聚(甲基丙烯酸甲酯)。将该终止反应应用于由2-甲基戊-4-烯酸甲酯的烯醇锂引发的MMA全同立构阴离子聚合，并在碱催化剂的作用下通过迈克尔加成将十一碳烯-1-硫醇加成到末端的碳-碳双键上。所得聚合物，即首尾均带有烯丙基的全同立构聚（甲基丙烯酸甲酯），通过第一代格鲁布斯催化剂的闭环复分解反应环化，得到环状全同立构聚（MMA），尽管同时发生了分子间复分解反应引起的大分子低聚。

2-(Halomethyl)acrylates were found to quantitatively terminate the stereospecific anionic polymerization of methyl methacrylate (MMA) to afford isotactic and syndiotactic poly(methyl methacrylate) possessing reactive carbon-carbon double bond at their terminal ends. This terminating reaction was applied to the isotactic specific anionic polymerization of MMA initiated by lithium enolate of methyl 2-methylpent-4-enoate, and undec-10-ene-1-thiol was added to the carbon-carbon double bond at terminal end via Michael addition with base catalyst. The resulting polymer, isotactic poly(methyl methacrylate) with allyl groups at both initial and terminal ends, was cyclized through ring closing metathesis reaction with 1st generation Grubbs' catalyst to afford cyclic isotactic poly(MMA), although oligomerization of macromonomer by intermolecular metathesis reaction occurred at the same time.