School of Science and Technology, Chemistry Division, University of Camerino, via S. Agostino 1, 62032 Camerino, Macerata, Italy.
Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, TX 76019-0065, USA.
Molecules. 2020 Jul 13;25(14):3184. doi: 10.3390/molecules25143184.
In this study, four new -(alkyl/aryl)imidazolium-borates were prepared, and their deprotonation reactions were investigated. Addition of BH•THF to -benzylimidazoles and -mesitylimidazoles leads to imidazolium-trihydridoborate adducts. Ammonium tetraphenylborate reacts with benzyl- or mesityl-imidazoles with the loss of one of the phenyl groups yielding the corresponding imidazolium-triphenylborates. Their authenticity was confirmed by CHN analysis, H-NMR, C-NMR, B-NMR, FT-IR spectroscopy, and electrospray ionization mass spectrometry (ESI-MS). 3-Benzyl-imidazolium-1-yl)trihydridoborate, (HIm)BH, and (3-mesityl-imidazolium-1-yl)trihydridoborate, (HIm)BH, were also characterized by X-ray crystallography. The reactivity of these new compounds as carbene precursors in an effort to obtain borate-NHC complexes was investigated and a new carbene-borate adduct (which dimerizes) was obtained via a microwave-assisted procedure.
在这项研究中，我们制备了四种新的 -(烷基/芳基)咪唑𬭩-硼酸酯，并对其去质子化反应进行了研究。BH•THF 与 -苄基咪唑和 -均三甲基苯并咪唑反应，生成咪唑𬭩-三氢硼酸酯加合物。四苯硼酸铵与苄基或均三甲基咪唑反应，失去一个苯基，生成相应的咪唑𬭩-三苯硼酸酯。它们的真实性通过 CHN 分析、H-NMR、C-NMR、B-NMR、FT-IR 光谱和电喷雾电离质谱（ESI-MS）得到了确认。3-苄基-1-咪唑𬭩三氢硼酸酯（HIm）BH 和 3-均三甲基苯并咪唑-1-咪唑𬭩三氢硼酸酯（HIm）BH 也通过 X 射线晶体学进行了表征。我们还研究了这些新化合物作为卡宾前体的反应性，以获得硼酸酯-NHC 配合物，并通过微波辅助程序获得了一种新的卡宾-硼酸酯加合物（其发生二聚化）。
