Electroreductive Intermolecular Coupling of Uracils with Aromatic Ketones: Synthesis of 6-Substituted and <i>cis</i>-5,6-Disubstituted 5,6-Dihydro-1,3-dimethyluracils and Their Transformation to 6-Substituted 1,3-Dimethyluracils, <i>trans</i>-5,6-Disubstituted 5,6-Dihydro-1,3-dimethyluracils, and 4,5,5-Trisubstituted 3-Methyloxazolizin-2-ones
作者:Naoki Kise、Yusuke Hamada、Toshihiko Sakurai
DOI:10.1021/acs.joc.6b00670
日期:2016.6.17
electroreductive coupling of 1,3-dimethyluracil, thymine, and 5-fluorouracil with aromatic ketones in the presence of TMSCl gave 6-substituted and cis-5,6-disubstituted 5,6-dihydro-1,3-dimethyluracils. The dehydrotrimethylsiloxylation of the adducts afforded 6-substituted and 5,6-fused 1,3-dimethyluracils. The detrimethylsilylation of the adducts with TBAF or 1 M HCl–MeOH gave 4,5,5-trisubstituted 3-methyloxazolizin-2-ones
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。