Chen Fengqian, Guan Xinyu, Li Hui, Ding Jiehua, Zhu Liangkui, Tang Bin, Valtchev Valentin, Yan Yushan, Qiu Shilun, Fang Qianrong
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun, 130012, China.
Deakin University, Institute for Frontier Materials, Geelong, Victoria, 3216, Australia.
Angew Chem Int Ed Engl. 2021 Oct 4;60(41):22230-22235. doi: 10.1002/anie.202108357. Epub 2021 Sep 1.
With excellent designability, large accessible inner surface, and high chemical stability, covalent organic frameworks (COFs) are promising candidates as metal-free heterogeneous catalysts. Here, we report two 3D radical-based COFs (JUC-565 and JUC-566) in which radical moieties (TEMPO) are uniformly decorated on the channel walls via a bottom-up approach. Based on grafted functional groups and suitable regular channels, these materials open up the application of COFs as highly efficient and selective metal-free redox catalysts in aerobic oxidation of alcohols to relevant aldehydes or ketones with outstanding turn over frequency (TOF) up to 132 h , which has exceeded other TEMPO-modified catalytic materials tested under similar conditions. These stable COF-based catalysts could be easily recovered and reused for multiple runs. This study promotes potential applications of 3D functional COFs anchored with stable radicals in organic synthesis and material science.
共价有机框架材料（COFs）具有出色的可设计性、较大的可及内表面和高化学稳定性，是很有前景的无金属多相催化剂候选材料。在此，我们报道了两种基于自由基的三维COFs（JUC-565和JUC-566），其中自由基部分（TEMPO）通过自下而上的方法均匀地修饰在孔壁上。基于接枝的官能团和合适的规则孔道，这些材料开启了COFs作为高效且选择性的无金属氧化还原催化剂在醇类有氧氧化为相关醛或酮反应中的应用，其出色的转化频率（TOF）高达132 h⁻¹，超过了在类似条件下测试的其他TEMPO修饰的催化材料。这些稳定的基于COF的催化剂可以很容易地回收并重复使用多次。本研究推动了锚定稳定自由基的三维功能COFs在有机合成和材料科学中的潜在应用。
