作者:Alan DeHope、Daniel Mendoza-Espinosa、Bruno Donnadieu、Guy Bertrand
DOI:10.1039/c1nj20170k
日期:——
Deprotonation of N,N-diisopropyl-C-ferrocenylaldiminium triflate 2 cleanly leads to the corresponding 1,2-diamino-1,2-diferrocenylethene 3, the dimer of the desired (amino)(ferrocenyl)carbene. Fulvene 6, obtained by addition of the lithium salt of tetramethylcyclopentadiene to methoxyformamidinium methylsulfate 5, reacts with dicarbonylcyclopentadienylbromoiron(II), and with a mixture of FeCl2 and Cp* lithium salt, affording the corresponding tetramethylferrocenylaldiminium salt 7, and nonamethylferrocenylaldiminium salt 8, respectively. Although the deprotonation of 7 gives a complex mixture of products, the treatment of 8 at −78 °C with sodium hexamethyldisilazide allowed for the isolation of the corresponding (amino)(ferrocenyl)carbene 9 as a yellow powder. However, even in the solid state, it is stable for less than 48 h at −20 °C. In addition to NMR spectroscopy, evidence for the carbene nature of 9 was found by a trapping experiment with sulfur that leads to the corresponding adduct 10, which was characterized by a single crystal X-ray diffraction study.
N,N-二异丙基-C-二茂铁基三亚硫酸盐 2 发生去质子化反应后,会生成相应的 1,2-二氨基-1,2-二茂铁烯3,即所需的(氨基)(二茂铁基)碳烯的二聚体。通过将四甲基环戊二烯锂盐加入甲氧基甲脒甲基硫酸盐 5 而得到的富烯烯 6 与二羰基环戊二烯溴铁(II)以及与氯化铁和 Cp* 锂盐的混合物反应,分别得到相应的四甲基二茂铁醛铵盐 7 和非二茂铁醛铵盐 8。虽然 7 的去质子化反应会产生复杂的混合物,但在 -78 °C 下用六甲基二硅氮化钠处理 8,可以分离出黄色粉末状的相应(氨基)(二茂铁基)碳化物 9。不过,即使是固态,它在 -20 °C 下的稳定性也不足 48 小时。除了核磁共振光谱之外,还通过与硫的捕获实验发现了 9 的碳烯性质,从而得到了相应的加合物 10,并通过单晶 X 射线衍射研究对其进行了表征。