Synthesis, structural characterization of benzimidazole-functionalized Ni(II) and Hg(II) N-heterocyclic carbene complexes and their applications as efficient catalysts for Friedel–Crafts alkylations
作者:Guoli Huang、Hongsheng Sun、Xiaojie Qiu、Yingzhong Shen、Juli Jiang、Leyong Wang
DOI:10.1016/j.jorganchem.2011.04.039
日期:2011.9
L1 = 3-(1-ethyl-1H-benzimidazol-2-yl)methyl)-1-((6-methylpyridin-2-yl)methyl)imidazolyl-idene), [Ni(L2)2(CH3CN)](PF6)2 (3b, L2 = 3-(1-ethyl-1H-benzimidazol-2-yl)methyl)-1-((6-methylpyridin-2-yl)-methyl)benzimidazolylidene), and [Hg(L1)2(CH3CN)2](PF6)2 (4) have been successfully prepared and fully characterized by NMR, ESI-MS spectroscopy, and X-ray diffraction analysis. The nickel complexes reveal
[Ni(L 1)2 ](PF 6)2(3a,L 1 = 3-(1-乙基-1 H-苯并咪唑-2-基)甲基)-1-((6-甲基吡啶-2-基) (Ni(L 2)2(CH 3 CN)](PF 6)2(3b,L 2 = 3-(1-乙基-1 H-苯并咪唑-2-基)甲基)-1- ((6-甲基吡啶-2--2-基)-甲基)苯并咪唑基亚烷基)和[Hg(L 1)2(CH 3 CN)2 ](PF 6)2(4)已成功制备,并已通过NMR,ESI-MS光谱和X射线衍射分析进行了全面表征。镍络合物显示出具有两个卡宾配体和苯并咪唑基团的顺式构型的平面结构。事实证明,镍络合物3b是在室温下以中等至优异的产率将吲哚与β-硝基苯乙烯进行吲哚的Friedel-Crafts烷基化的高效催化剂。的晶体堆积结构4个的是双链1D超分子链通过链间的苯并咪唑环和吡啶形成的显示环面-面π - π堆积相互作用。