Versatile 1,2- and 1,3-Dipole Behavior of the 1-Arsa-3-Germaallene Tip(<i>t</i>-Bu)Ge═C═AsMes*: Formation of a Heterocyclic Arsa(germa)carbene (AsGeHC)
作者:Dumitru Ghereg、Jean-Marc Sotiropoulos、Jean Escudié、Karinne Miqueu、Dimitri Matioszek、Sonia Ladeira、Nathalie Saffon-Merceron
DOI:10.1021/om200968x
日期:2012.2.13
1-arsa-3-germaallene Tip(t-Bu)Ge═C═AsMes* (1; Tip = 2,4,6-triisopropylphenyl, Mes* = 2,4,6-tri-tert-butylphenyl) reacts with selenium, fluorenone, N-tert-butylphenylnitrone, and 9,10-phenanthrenequinone as a 1,2-dipole by the Ge═C double bond, to give the corresponding three-, four-, five-, and six-membered-ring derivatives 2–5, respectively. Both [2 + 2] and [2 + 4] cycloadditions involving the Ge═C double bond
1-ARSA -3- germaallene提示(吨-Bu)Ge═C═AsMes*(1 ;提示= 2,4,6-三异丙基,MES * = 2,4,6-三-叔丁基苯基)发生反应以硒,芴酮,ñ -叔-butylphenylnitrone,和9,10-菲醌如由Ge═C双键的1,2-偶极子,以得到相应的三,四,五- ,和六元环分别衍生2 – 5。在1和苄基之间观察到涉及Ge═C双键的[2 + 2]和[2 + 4]环加成反应,生成四元和六元环衍生物6和7。与之形成鲜明对比的是1通过[3 + 2]环加成反应,以整个Ge═CphenylAs单元与作为1,3-偶极的联苯乙烯酮反应,得到瞬态杂环arsa(germa)卡宾12。进行DFT计算以了解此特定行为。具有砷原子的NHC的第一个较重的类似物重排至三环化合物11。