Iridium, ruthenium, and palladium complexes containing a mesoionic fused imidazolylidene ligand
作者:Ana Petronilho、Helge Mueller-Bunz、Martin Albrecht
DOI:10.1016/j.jorganchem.2014.03.021
日期:2015.1
the imidazolium N1–C2 bond and hence protected from forming normal imidazole-2-ylidene complexes undergoes selective activation of the C5–H bond with Ag2O, i.e. at the imidazolium carbon that is proximal to the pyridine nitrogen. While the silver carbene complex is unstable, transmetallation with [IrCp*Cl2]2, [RuCl2(cym)]2, and [PdCl(allyl)]2 afforded stable mesoionic carbene complexes. Two iridium(III)
咪唑并[1,2- a ]吡啶由在咪唑N1-C2键上与咪唑盐融合的吡啶组成,因此可防止形成正常的咪唑-2-亚烷基配合物,并通过Ag 2 O选择性激活C5-H键,即在靠近吡啶氮的咪唑碳上。卡宾银配合物不稳定时,会与[IrCp * Cl 2 ] 2,[RuCl 2(cym)] 2和[PdCl(烯丙基)] 2发生金属转移提供稳定的中离子卡宾配合物。在结构上表征了两种在金属中心包含一个稠合卡宾配体的铱(III)配合物和一个在两个金属烯基上包含两个卡宾配体的钯(II)配合物。与卡宾碳相邻的取代基的缺乏阻止了翼尖基团的活化,特别是在(中等)酸性条件下,降低了络合物的稳定性。