Carver Colin T, Benitez Diego, Miller Kevin L, Williams Bryan N, Tkatchouk Ekaterina, Goddard William A, Diaconescu Paula L
Department of Chemistry & Biochemistry, University of California, Los Angeles, California 90095, USA.
J Am Chem Soc. 2009 Jul 29;131(29):10269-78. doi: 10.1021/ja902794w.
Group III alkyl complexes supported by a ferrocene diamide ligand (1,1'-fc(NSi(t)BuMe(2))(2)) have been found to be reactive toward aromatic N-heterocycles such as 1-methylimidazole and pyridines. These reactions were investigated experimentally and computationally. An initial C-H activation event is followed by a coupling reaction to form biheterocyclic complexes, in which one of the rings is dearomatized. In the case of 1-methylimidazole, the biheterocyclic compound could not be isolated and further led to an imidazole ring-opened product; in the case of pyridines, it transformed into an isomer with extended conjugation of double bonds. Mechanisms for both reactions are proposed on the basis of experimental and computational results. DFT calculations were also used to show that an energetically accessible pathway for the ring-opening of pyridines exists.
已发现由二茂铁二酰胺配体（1,1'-fc(NSi(t)BuMe(2))(2)）支撑的Ⅲ族烷基配合物对诸如1-甲基咪唑和吡啶等芳族N-杂环具有反应活性。对这些反应进行了实验和计算研究。最初的C-H活化事件之后是偶联反应，形成双杂环配合物，其中一个环发生去芳构化。在1-甲基咪唑的情况下，无法分离出双杂环化合物，并且进一步导致咪唑环开环产物；在吡啶的情况下，它转化为具有扩展双键共轭的异构体。根据实验和计算结果提出了两种反应的机理。DFT计算还用于表明存在吡啶开环的能量可及途径。
