Terminal alkynes display high reactivity toward Ru-carbene metathesis catalysts. However, the formation of a less reactive bulky carbene hinders their homopolymerization. Simultaneously, the higher reactivity of alkynes does not allow efficient cross propagation with sterically less-hindered cycloalkene monomers, resulting in inefficient copolymerization. Nonetheless, terminal alkynes undergo rapid cross-metathesis with vinyl ethers. Therefore, an efficient cross propagation can be achieved with terminal alkynes and cyclic enol ether monomers. Here, we show that terminal alkyne derivatives can be copolymerized in an alternating fashion with 2,3-dihydrofuran using Grubbs’ third generation catalyst (G3). A linear relationship of the number-average molecular weight versus monomer to initiator ratio and block copolymer synthesis confirmed a controlled copolymerization. The SEC and NMR analyses of the synthesized copolymers confirmed the excellent control over molecular weight and exclusive alternating nature of the copolymer. The regioselective chain transfer of G3 to vinyl ether and the high reactivity of the Fischer-type Ru carbene toward terminal alkynes was also exploited for polymer conjugation. Finally, the presence of an acid labile backbone functionality in the synthesized alternating copolymers allowed complete degradation of the copolymer within a short time interval which was confirmed by SEC analyses.

中文翻译：

---

末端炔烃的可控交替复分解共聚

末端炔烃对钌-卡宾复分解催化剂表现出高反应性。然而，反应性较低的大卡宾的形成阻碍了它们的均聚。同时，炔烃的较高反应性不允许与空间位阻较小的环烯烃单体进行有效的交叉传播，导致共聚效率低下。尽管如此，末端炔烃与乙烯基醚会发生快速交叉复分解。因此，使用末端炔烃和环状烯醇醚单体可以实现有效的交叉传播。在这里，我们展示了末端炔烃衍生物可以使用 Grubbs 的第三代催化剂（G3 ）以交替方式与 2,3-二氢呋喃共聚。）。数均分子量与单体与引发剂的比例和嵌段共聚物合成的线性关系证实了受控共聚。合成共聚物的 SEC 和 NMR 分析证实了对分子量的出色控制和共聚物的独特交替性质。G3到乙烯基醚的区域选择性链转移和 Fischer 型钌卡宾对末端炔烃的高反应性也被用于聚合物共轭。最后，合成的交替共聚物中酸不稳定主链官能团的存在允许共聚物在短时间内完全降解，这通过 SEC 分析得到证实。