Synthesis and [2+2] Cycloaddition with Tetracyanoethylene of Ene-Diyne Scaffolds Bearing Ferrocenes at the Periphery
Synthesis and [2+2] Cycloaddition with Tetracyanoethylene of Ene-Diyne Scaffolds Bearing Ferrocenes at the Periphery
复制标题
外围承载二茂铁烯-二炔支架的合成及[2 2]四氰乙烯环加成
DOI：
10.1002/ejoc.201100650
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发表时间：
2011
影响因子：
2.8
通讯作者：
et al
中科院分区：
文献类型：
--
作者：
Taku Shoji;et al
乙炔基二茂铁与9-二溴亚甲基-9H-荧烯(4)和9，10‐bis(dibromomethylene)‐9，10‐dihydroanthracene(5)通过简单的一锅Sonogashira-Hagihara偶联反应合成了外围带有二茂铁基的烯-二炔体系1和2。烯二酮与四氰乙烯(TCNE)进行[2+2]环加成反应，然后开环生成环丁烯，得到相应的1，1，4，4-四氰基丁二烯(TCBD)衍生物。用循环伏安法(CV)和差示脉冲伏安法(DPV)研究了烯二炔化合物1和2以及TCBD衍生物6的氧化还原行为，结果表明，除了TCBD衍生物6中TCBD部分的两电子还原外，它们的电化学氧化性能还取决于分子中二茂铁单元的数量，以及TCBD部分的两电子还原。此外，对于TCBD衍生物，在电化学氧化条件下和还原条件下的可见光谱观察到显著的颜色变化。
The ene–diyne systems1and2, possessing ferrocenyl groups at the periphery, were prepared by a simple one‐pot Sonogashira–Hagihara coupling reaction of ethynylferrocene with 9‐dibromomethylene‐9H‐fluorene (4) and 9,10‐bis(dibromomethylene)‐9,10‐dihydroanthracene (5). Ene–diyne1reacted with tetracyanoethylene (TCNE) in a formal [2+2] cycloaddition reaction, followed by ring opening of the initially formed [2+2] cycloadduct, cyclobutene, to afford the corresponding 1,1,4,4‐tetracyanobutadiene (TCBD) derivative6in good yield. The redox behavior of the ene–diyne compounds1and2, and the TCBD derivative6was examined by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), which revealed their electrochemical oxidation properties with multi‐electron transfer depending on the number of ferrocene units in the molecule, in addition to the two‐electron reduction of the TCBD moiety in the case of TCBD derivative6. Moreover, a significant color change was observed by visible spectroscopy under electrochemical oxidation conditions and under reduction conditions in the case of TCBD derivative6.