Living ROMP has become an important technique for preparing well-controlled, highly functional polymers; however, installing functional groups at the end of living ROMP polymers is not as straightforward as ROMP itself. We report a simple, efficient strategy to introduce functionalities at the chain end of living polynorbornenes via highly selective single addition of disubstituted 1,1-cyclopropenes (CPEs) with no homopropagation. Unlike many other methods for ROMP chain end functionalization, our method does not result in catalyst termination, allowing for further functionalization after CPE addition. The remarkable reactivity of such CPEs allowed for quantitative chain end functionalization to install a variety of useful functionalities, including halides, aldehydes, ketones, amines, and dyes, without using a large excess of CPEs. These polymer chain ends can be readily modified using a range of postpolymerization modifications.

中文翻译：

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通过单次添加功能性环丙烯对活性开环复分解聚合物进行高效、简便的端基控制

Living ROMP 已成为制备可控性高的高功能聚合物的重要技术；然而，在活性 ROMP 聚合物末端安装官能团并不像 ROMP 本身那么简单。我们报告了一种简单、有效的策略，通过高选择性的单次加成二取代的 1,1-环丙烯 (CPE) 在活性聚降冰片烯的链端引入功能，无需同质增殖。与许多其他 ROMP 链末端功能化方法不同，我们的方法不会导致催化剂终止，从而允许在添加 CPE 后进行进一步的功能化。这种 CPE 的显着反应性允许定量链端官能化以安装各种有用的功能，包括卤化物、醛、酮、胺和染料，而无需使用大量过量的 CPE。