The influence of electron delocalization upon the stability and structure of potential N-heterocyclic carbene precursors with 1,3-diaryl-imidazolidine-4,5-dione skeletons
作者:Matthew G. Hobbs、Taryn D. Forster、Javier Borau-Garcia、Chrissy J. Knapp、Heikki M. Tuononen、Roland Roesler
DOI:10.1039/b9nj00771g
日期:——
6-dimethylphenyl)-[2,2′]diimidazolidinyl-4,5,4′,5′-tetraone (2b) was formed via the reductive coupling of 1b, while 1,3-bis(2,6-diisopropylphenyl)-4,5-dioxoimidazolidin-2-yl acetate (3c) was formed as the result of a metathesis reaction with mercury(II) acetate. Chloride abstraction resulted in the formation of imidazolium-4,5-dione salts (4a–c) that decomposed rapidly, except in the case of the kinetically-stabilized
靶向具有增强的π受体特征的N杂环卡宾(NHC)N-氟苯基从相应的缩合反应中分离出2-氯-1,3-双(氟苯基)咪唑烷-4,5-二酮(1a–c)取代基甲am 和 草酰氯。这些NHC的正式加合物氯化氢 证明与烷基卤相似的反应活性: 1,3,1',3'-四(2,6-二甲基苯基)-[2,2']二咪唑啉基-4,5,4',5'-四酮(2b)是通过1b的还原耦合形成的,而1,3-双(2,6-二异丙基苯基)-4,5-二氧杂咪唑啉-2-乙酸乙酸酯(3c)是由于与的复分解反应的结果而形成的。汞(II)乙酸盐。 氯化物 抽象导致形成 咪唑-4,5-二酮迅速分解的盐(4a–c),除非在动力学上稳定1,3-双(2,6-二异丙基苯基)咪唑-4,5-二酮六氟磷酸盐 4c。全部咪唑-4,5-二酮六氟磷酸盐分解为中性2-氟-1,3-双(芳基)咪唑烷-4,5-二酮(盐5A-C )通过 氟化物抽象。还制备了2-甲氧基-1,3-二(芳基)咪唑烷-4