Synthesis of Tri- or Tetrasubstituted Pyrimidine Derivatives through the [5+1] Annulation of Enamidines with either N,N-Dimethylformamide Dialkyl Acetals or Orthoesters and Their Application in a Ring Transformation of Pyrimidines to Pyrido[2,3-d]pyrimidi
作者:Toshiaki Sasada、Youichi Aoki、Reiko Ikeda、Norio Sakai、Takeo Konakahara
DOI:10.1002/chem.201100040
日期:2011.8.16
The [5+1] annulation of enamidines, which were prepared from functionalized silanes, organolithium compounds and two nitriles, with N,N‐dimethylformamide dialkyl acetals as the C1 unit is described, leading to the synthesis of tri‐ and tetrasubstituted pyrimidine derivatives under catalyst‐ and solvent‐free reaction conditions. Furthermore, the [5+1] annulation of enamidines by using orthoesters as
描述了由功能化的硅烷,有机锂化合物和两个腈以N,N-二甲基甲酰胺二烷基乙缩醛作为C1单元制备的en啶的[5 + 1]环化反应,可在以下条件下合成三和四取代的嘧啶衍生物无催化剂和无溶剂的反应条件。此外,描述了通过使用原酸酯作为C1单元的en啶的[5 + 1]环化,其中催化量的ZnBr 2催化环化以在甲苯或二甲苯回流条件下产生多取代的嘧啶。此外,还原性开环反应与[Mo(CO)6 ]结合,随后分子内环化反应与tBuOK有效地导致含有异恶唑基和乙氧基取代基的嘧啶的骨架转化,从而以优异的产率形成吡啶并[2,3 - d ]嘧啶-5-酮骨架。