Zhang Zongnan, Li Xinyang, Zhou Dezhong, Ding Shujiang, Wang Minyan, Zeng Rong
School of Chemistry and School of Chemical Engineering and Technology, Xi'an Jiaotong University, Xi'an 710049, P. R. China.
State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, P. R. China.
J Am Chem Soc. 2023 Apr 5;145(13):7612-7620. doi: 10.1021/jacs.3c01100. Epub 2023 Mar 24.
The efficient conversion of a C-H bond in the polyether chain to other functional groups provides great opportunities for development of novel applications in many research fields. However, this field is quite underdeveloped due to the key challenge on controlling the selectivity of the C-H bond functionalization over the chain cleavage. In this work, we report a controllable C-H bond alkylation of polyethers under mild conditions via photoinduced iron catalysis. The level of functionalization could be controlled by using different amounts of alkenes and various reaction times, while the molecular weight distributions were maintained narrow. A broad scope of electron-deficient alkenes containing nitrile, ester, epoxide, terminal alkynyl, 2,5-dioxotetrafuranyl, and 2,5-dioxopyrrolidinyl groups could be utilized to functionalize the different polyethers with great efficiencies. The potential applications of the modified polyethylene glycols and polyethylene oxides were explored by the preparation of novel hydrogels and solid-state electrolytes with enhancement of lithium ion conductivities. Moreover, the density functional theory calculation disclosed the plausible mechanism and explained the high selectivity for the C-H alkylation.
将聚醚链中的碳氢键高效转化为其他官能团，为许多研究领域开发新应用提供了巨大机遇。然而，由于在控制碳氢键官能化选择性以避免链断裂方面存在关键挑战，该领域发展相当滞后。在这项工作中，我们报道了通过光诱导铁催化在温和条件下实现聚醚的可控碳氢键烷基化反应。官能化程度可通过使用不同量的烯烃和不同反应时间来控制，同时分子量分布保持较窄。一系列含腈基、酯基、环氧基、末端炔基、2,5 - 二氧代四氢呋喃基和2,5 - 二氧代吡咯烷基的缺电子烯烃可用于高效官能化不同的聚醚。通过制备具有增强锂离子电导率的新型水凝胶和固态电解质，探索了改性聚乙二醇和聚环氧乙烷的潜在应用。此外，密度泛函理论计算揭示了可能的反应机理，并解释了碳氢键烷基化的高选择性。
