Chemistry. 2014 Mar 10;20(11):3061-8. doi: 10.1002/chem.201304478.
The reactions of the Group 4 metallocene alkyne complexes, [Cp2M(η2-Me3SiC2SiMe3)] (1 a: M=Ti, 1 b: M=Zr, Cp=η5-pentamethylcyclopentadienyl), with the ferrocenyl nitriles, Fc-CN and Fc-C≡C-C≡N (Fc=Fe(η5-C5H5)(η5-C5H4)), is described. In case of Fc-C≡N an unusual nitrile–nitrile C-C homocoupling was observed and 1-metalla-2,5-diaza-cyclopenta-2,4-dienes (3 a, b) were obtained. As the first step of the reaction with 1 b, the nitrile was coordinated to give [Cp*2Zr(η2-Me3SiC2SiMe3)(N≡C-Fc)] (2 b). The reactions with the 3-ferrocenyl-2-propyne-nitrile FcC≡C-C≡N lead to an alkyne–nitrile C-C coupling of two substrates and the formation of 1-metalla-2-aza-cyclopenta-2,4-dienes (4 a, b). For M=Zr, the compound is stabilized by dimerization as evidenced by single-crystal X-ray structure analysis. The electrochemical behavior of 3 a, b and 4 a, b was investigated, showing decomposition after oxidation, leading to different redox-active products.
描述了茂基金属炔烃配合物[Cp2M(η2-Me3SiC2SiMe3)]（1a：M=Ti，1b：M=Zr，Cp=η5-戊甲基环戊二烯基）与二茂铁氰化物 Fc-CN 和 Fc-C≡C-C≡N（Fc=Fe(η5-C5H5)(η5-C5H4)）的反应。在 Fc-C≡N 的情况下，观察到了不寻常的腈-腈 C-C 同偶联，得到了 1-金属-2,5-二氮杂环戊二烯（3a，b）。作为 1b 与反应的第一步，腈与配合物配位，得到[Cp*2Zr(η2-Me3SiC2SiMe3)(N≡C-Fc)]（2b）。与 3-二茂铁基-2-丙炔腈 FcC≡C-C≡N 的反应导致两个底物的炔烃-腈 C-C 偶联和 1-金属-2-氮杂环戊二烯（4a，b）的形成。对于 M=Zr，该化合物通过二聚化稳定，这一点通过单晶 X 射线结构分析得到证明。研究了 3a，b 和 4a，b 的电化学行为，发现它们在氧化后会分解，导致不同的氧化还原活性产物。
