在TMCSC1的存在下,1,3-二甲基尿嘧啶,胸腺嘧啶和5-氟尿嘧啶与芳族酮的电还原偶联得到6-取代的和顺式-5,6-二取代的5,6-二氢-1,3-二甲基尿嘧啶。加合物的脱氢三甲基甲硅烷氧基化得到6-取代的和5,6-稠合的1,3-二甲基尿嘧啶。用TBAF或1 M HCl-MeOH对加合物进行脱甲基甲硅烷基化反应,除简单的脱甲硅烷基化醇外,还得到4,5,5-三取代的3-甲基恶唑嗪-2-酮或3-甲基恶唑嗪-2-亚胺。通过在猫的存在下加热,将顺式-5,6-二取代的5,6-二氢-1,3-二甲基尿嘧啶异构化为相应的反式异构体。DMAP。该顺-和反式-5,6-二取代的5,6-二氢-1,3-二甲基尿嘧啶通过其1 H NMR光谱的偶合常数J 5,6进行赋值。
Reductive coupling of 1,3-dimethyluracils with benzophenone by low-valent titanium: unusual two-to-one coupling
作者:Naoki Kise、Shinta Akazai、Toshihiko Sakurai
DOI:10.1016/j.tetlet.2011.09.154
日期:2011.12
The reductivecoupling of 1,3-dimethyluracil with benzophenone by Zn–TiCl4 in THF gave unusual two-to-one adduct and its further reduced product. The reductivecoupling of 1,3-dimethyl-5-fluorouracil with benzophenone by Zn–TiCl4 also gave two-to-one adduct. 1,3-Dimethylthymine was, however, completely inert under the same conditions.