J Am Chem Soc. 2019 Aug 28;141(34):13619-13624. doi: 10.1021/jacs.9b06328. Epub 2019 Aug 19.
Herein, we report the development of a scalable and synthetically robust building block based on norbornadiene (NBD) that can be broadly incorporated into a variety of macromolecular architectures using traditional living polymerization techniques. By taking advantage of a selective and rapid deprotection with tetrazine, highly reactive "masked" cyclopentadiene (Cp) functionalities can be introduced into synthetic polymers as chain-end groups in a quantitative and efficient manner. The orthogonality of this platform further enables a cascade "click" process where the "unmasked" Cp can rapidly react with dienophiles, such as maleimides, through a conventional Diels-Alder reaction. Coupling proceeds with quantitative conversions allowing high molecular weight star and dendritic block copolymers to be prepared in a single step under ambient conditions.
在此，我们报告了一种基于降冰片二烯（NBD）的可扩展且合成稳健的构建块的开发，该构建块可以使用传统的活性聚合技术广泛纳入各种大分子结构中。通过利用四嗪的选择性和快速脱保护作用，可以以定量和有效的方式将高反应性的“掩蔽”环戊二烯（Cp）官能团作为链端基团引入合成聚合物中。该平台的正交性进一步实现了级联“点击”过程，其中“未掩蔽”的 Cp 可以通过传统的 Diels-Alder 反应与马来酰亚胺等亲二烯体快速反应。偶联以定量转化率进行，允许在环境条件下一步制备高分子量星形和树枝状嵌段共聚物。
