Department of Chemistry, Faculty of Science and Arts, İnönü University, 44280 Malatya, Turkey.
Catalysis Research and Application Center, İnönü University, 44280 Malatya, Turkey.
Molecules. 2018 Mar 13;23(3):647. doi: 10.3390/molecules23030647.
A series of new benzimidazolium halides were synthesized in good yields as unsymmetrical -heterocyclic carbene (NHC) precursors containing the N-CH₂-arene group. The benzimidazolium halides were readily converted into ruthenium(II)-NHC complexes with the general formula [RuCl₂(η⁶,η¹-arene-CH₂-NHC)]. The structures of all new compounds were characterized by ¹H NMR (Nuclear Magnetic Resonance), C NMR, FT-IR (Fourier Transform Infrared) spectroscopy and elemental analysis techniques. The single crystal structure of one benzimidazole ruthenium complex, , was determined. The complex is best thought of as containing an octahedrally coordinated Ru center with the arene residue occupying three sites, the remaining sites being occupied by a (carbene)C-Ru bond and two Ru-Cl bonds. The catalytic activity of [RuCl₂(η⁶,η-arene-CH₂-NHC)] complexes was evaluated in the direct (hetero)arylation of 2-phenylpyridine with (hetero)aryl chlorides in water as the nontoxic reaction medium. These results show that catalysts and were the best for monoarylation with simple phenyl and tolyl chlorides. For functional aryl chlorides, , , and appeared to be the most efficient.
一系列新的苯并咪唑卤化物作为含有 N-CH₂-芳基的非对称杂环卡宾（NHC）前体以良好的产率合成。苯并咪唑卤化物很容易转化为通式为[RuCl₂(η⁶,η¹-芳基-CH₂-NHC)]的钌（II）-NHC 配合物。所有新化合物的结构均通过¹H NMR（核磁共振）、C NMR、FT-IR（傅里叶变换红外）光谱和元素分析技术进行了表征。一个苯并咪唑钌配合物的单晶结构， ，被确定。该配合物最好被认为含有一个八面体配位的 Ru 中心，其中芳基残基占据三个位置，其余位置由（卡宾）C-Ru 键和两个 Ru-Cl 键占据。[RuCl₂(η⁶,η-芳基-CH₂-NHC)]配合物的催化活性在水作为无毒反应介质中 2-苯基吡啶与（杂）芳基氯化物的直接（杂）芳基化反应中进行了评估。这些结果表明，催化剂 和 对于简单的苯基和甲苯基氯化物的单芳基化是最好的。对于功能芳基氯化物， ， ， 和 似乎是最有效的。
