Supramolecular Formation Induced by Recogonization of Stereoregularity in Cyclick Polymer

发现2-(卤甲基)丙烯酸酯能定量终止甲基丙烯酸甲酯(MMA)的立体定向阴离子聚合，得到末端具有活性碳-碳双键的等规聚和间规聚(甲基丙烯酸甲酯)。将该终止反应应用于2-甲基戊烯-4-烯酸甲酯锂引发的甲基丙烯酸甲酯等规专一性阴离子聚合，并在碱催化下通过Michael加成反应在末端的碳-碳双键上加成了undec-10-烯-1-硫醇。尽管大分子单体通过分子间歧化反应发生齐聚反应，但合成的聚合物--端烯丙基和端烯丙基的等规聚甲基丙烯酸甲酯在第一代格拉布斯催化剂的作用下，通过环合复分解反应得到了环状等规聚(MMA)。

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.