报道了在碱性条件下由嘧啶和四嗪直接合成嘧啶并[4,5- d ]哒嗪的方法。去质子化的取代的5-卤代嘧啶易于通过复杂的反应途径以高度区域选择性的方式与各种取代的四嗪发生反应,这得到了DFT计算的支持。该机理导致通过经验观察到的区域异构体而不经过可能的戊炔中间体。关于5-卤代嘧啶的这些结果导致开发了基于6-卤代嘧啶的相反的区域异构体的制备方法。
Conjugated systems built by connecting one electron-donor triphenylamine to an electron-withdrawing tetrazine have been prepared using various linkers.
Despite previous report of failure of this reaction, a series of new monoalkyltetrazines and a dialkyltetrazine have been prepared by nucleophilic aromatic substitution, albeit sometimes in moderate yields. In addition to the original synthetic procedure, the fluorescence and electrochemical behaviour of these new compounds have been reported.
[GRAPHICS]A series of substituted chlorotetrazines were reacted with different terminal alkynes under Sonogashira or Negishi coupling conditions to furnish alkynyl-tetrazines in good to moderate yield. The electron-donating properties of the substituent on the tetrazine core were found to have a significant influence on the success of the reaction. These results constitute the first cross-coupling reactions on tetrazines.