Unprecedented salt-promoted direct arylation of acidic sp2 CH bonds under heterogeneous Ni-MOF-74 catalysis: Synthesis of bioactive azole derivatives
作者:Huong T.T. Nguyen、Duc N.A. Doan、Thanh Truong
DOI:10.1016/j.molcata.2016.11.009
日期:2017.1
Herein, nickel-based metal-organicframework, Ni-MOF-74, was synthesized by a solvothermal method and its properties was characterized by a host of techniques. Ni-MOF-74 exhibited exceptional catalyticactivity toward the direct arylation of azoles via C H activation while other Ni-MOFs, nickel-based heterogeneous systems, and homogeneous counter parts displayed lower activity. Optimal conditions involved
摘要 本文采用溶剂热法合成了镍基金属有机骨架Ni-MOF-74,并通过多种技术对其性能进行了表征。Ni-MOF-74 通过 CH 活化对唑类的直接芳基化表现出优异的催化活性,而其他 Ni-MOF、镍基非均相体系和均相配对部件表现出较低的活性。最佳条件涉及在二甘醇二甲醚溶剂中使用 Li 2 CO 3 或 KCl 盐 18 小时,并且不需要额外的配体。这是使用氯化钾盐作为促进杂环芳基化的第一个也是前所未有的报告。通过避免使用强碱和氧化剂,优化的条件与广泛的官能团和杂环兼容。此外,利用 Ni-MOF-74 的大孔径尺寸,我们能够利用优化的条件成功合成几种具有生物活性的芳基化唑衍生物。以前使用非均相催化剂来处理这些生物活性化合物的研究在文献中没有进行。浸出试验表明,不太可能通过浸出的活性镍物种进行均相催化。因此,催化剂很容易从反应混合物中分离出来并重复使用多次,而催化活性没有明显降低。
Diheteroarylmethanes. 5.<sup>1</sup> <i>E</i>−<i>Z</i> Isomerism of Carbanions Substituted by 1,3-Azoles: <sup>13</sup>C and <sup>15</sup>N π-Charge/Shift Relationships as Source for Mapping Charge and Ranking the Electron-Withdrawing Power of Heterocycles
作者:Alessandro Abbotto、Silvia Bradamante、Giorgio A. Pagani
DOI:10.1021/jo951884l
日期:1996.1.1
pi-charge mapping in these carbanionic systems, and the results point to considerable delocalization of the electron pair(s) of the oxygen and pyrrolic nitrogen atoms at position 1 in oxazole and imidazole toward the pyridic nitrogen at position 3 of the rings (in both the neutrals and the carbanionic species). On the contrary, not only does the sulfur atom in thiazole derivatives not delocalize any negative