Systematic study on free radical hydrothiolation of unsaturated monosaccharide derivatives with exo- and endocyclic double bonds
作者:László Lázár、Magdolna Csávás、Ádám Hadházi、Mihály Herczeg、Marietta Tóth、László Somsák、Terézia Barna、Pál Herczegh、Anikó Borbás
DOI:10.1039/c3ob40547h
日期:——
reacted with various thiols by irradiation with UV light in the presence of a cleavable photoinitiator. The photoinduced radical-mediated hydrothiolation reactions showed highly varying overall conversions depending not only on the substitution pattern and electron-density of the double bond but also on the nature and substitution pattern of the thiol partner. Out of the applied thiols thiophenol, producing
通过在可裂解的光引发剂的存在下用紫外线照射,使糖的外环和内环双键以及烯键的末端双键与各种硫醇反应。光诱导的自由基介导的氢硫醇化反应显示出很大变化的总转化率,这不仅取决于双键的取代方式和电子密度,还取决于硫醇配偶体的性质和取代方式。在所施加的硫醇中,产生高度稳定的噻吩基的硫酚对每种烯烃的反应性最低。在大多数情况下,氢硫醇化反应具有完全的区域选择性和立体选择性。将1,2:3,4-二-O-异亚丙基-6-硫代-α- D-吡喃半乳糖成功添加到2,3-不饱和N-乙酰神经氨酸衍生物提供(3→6)-S连接的假二糖,表明带有吸电子取代基的Neu5Ac-2-ene的内环双键在光诱导的硫醇-烯偶联反应中显示出足够的反应性。 。