Chen Jingwen, Zhang Yuanyuan, Chen Xiaoling, Dai Siyun, Bao Zongbi, Yang Qiwei, Ren Qilong, Zhang Zhiguo
Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, P. R. China.
Institute of Zhejiang University-Quzhou, Quzhou 324000, P. R.China.
ACS Appl Mater Interfaces. 2021 Mar 10;13(9):10845-10854. doi: 10.1021/acsami.0c20369. Epub 2021 Mar 2.
Cross-dehydrogenative coupling (CDC) is an effective tool for carbon-carbon bond formation in chemical synthesis. Herein, we report a metal-organic framework (MOF) possessing dual Lewis acidic Cr sites and sulfonic acid sites (MIL-101(Cr)-SOH) as an efficient catalytic material for direct cross-coupling of xanthene and different nucleophiles using O as the oxidant. The highly porous structure of MIL-101(Cr)-SOH enables the free access of reactants to the catalytic active sites inside MOF pores. Kinetic studies indicated that the Cr sites of MOF accelerate the rate-limiting autoxidation reaction of xanthene, which synergistically work with the sulfonic acid group on MOF ligands in promoting the CDC reactions. Besides, the catalytic system shows excellent functional group compatibility, and a variety of valuable xanthene derivatives were synthesized with satisfactory yields. Furthermore, MIL-101(Cr)-SOH can be reused and its catalytic activity and crystal structure remain after six consecutive runs.
交叉脱氢偶联（CDC）是化学合成中形成碳-碳键的有效工具。在此，我们报道了一种具有双路易斯酸性Cr位点和磺酸位点的金属有机框架（MOF）（MIL-101(Cr)-SOH），它是一种高效的催化材料，用于以O为氧化剂，使呫吨与不同亲核试剂直接交叉偶联。MIL-101(Cr)-SOH的高度多孔结构使反应物能够自由进入MOF孔内的催化活性位点。动力学研究表明，MOF的Cr位点加速了呫吨的限速自氧化反应，该反应与MOF配体上的磺酸基团协同作用，促进CDC反应。此外，该催化体系显示出优异的官能团兼容性，并且以令人满意的产率合成了多种有价值的呫吨衍生物。此外，MIL-101(Cr)-SOH可以重复使用，并且在连续六次运行后其催化活性和晶体结构仍然保持。
