Liu Lili, Tai Xishi, Zhou Xiaojing, Xin Chunling, Yan Yongmei
School of Chemistry & Chemical Engineering and Environmental Engineering, Weifang University, Weifang, 261061, China.
Sci Rep. 2017 Oct 5;7(1):12709. doi: 10.1038/s41598-017-13081-0.
Postsynthetic modification of metal-organic framework is a general and practical approach to access MOF-based catalysts bearing multiple active sites. The isoreticular metal-organic framework-3 (IRMOF-3) was modified with lactic acid through condensation reaction of the carboxyl group of lactic acid and amino group present in IRMOF-3 frameworks. Au was subsequently anchored onto the metal-organic framework IRMOF-3 using postsynthetic modification. The synthezized IRMOF-3-LA-Au (LA = lactic acid) was characterized by powder X-ray diffraction, N adsorption-desorption, infrared spectroscopy, liquid-state nuclear magnetic resonance, thermogravimetric analysis, H-temperature programmed reduction, transmission electro microscopy, and inductively coupled plasma-optical emission spectrometry. IRMOF-3-LA-Au acted as an efficient heterogeneous catalyst in the synthesis of propargylamines by three-component coupling reaction of aldehyde, alkyne, and amine. Moreover, the catalyst is applicable to various substituted substrates, including aromatic and aliphatic aldehydes, alkyl- and aryl-substituted terminal alkynes, and alicyclic amines. In addition, the catalyst can be easily separated from the mixture and can be reused for four consecutive cycles.
金属有机框架的合成后修饰是一种获得具有多个活性位点的基于金属有机框架催化剂的通用且实用的方法。通过乳酸的羧基与IRMOF-3框架中存在的氨基的缩合反应，用乳酸对同构金属有机框架-3（IRMOF-3）进行修饰。随后利用合成后修饰将金锚定到金属有机框架IRMOF-3上。通过粉末X射线衍射、N吸附-脱附、红外光谱、液态核磁共振、热重分析、H程序升温还原、透射电子显微镜和电感耦合等离子体发射光谱对合成的IRMOF-3-LA-Au（LA =乳酸）进行了表征。IRMOF-3-LA-Au在醛、炔烃和胺的三组分偶联反应合成炔丙胺中作为一种高效的多相催化剂。此外，该催化剂适用于各种取代底物，包括芳香族和脂肪族醛、烷基和芳基取代的末端炔烃以及脂环族胺。此外，该催化剂可以很容易地从混合物中分离出来，并可以连续重复使用四个循环。
