Synthesis of functionalized thiazoles via attack of heterocyclic nucleophiles on allenyl isothiocyanates
作者:Baker Jawabrah Al-Hourani、Klaus Banert、Nermeen Gomaa、Kai Vrobel
DOI:10.1016/j.tet.2008.03.074
日期:2008.6
New examples of substituted thiazole derivatives carrying different heterocyclic ring systems at C-2 position were prepared via the reaction of several allenyl isothiocyanates with nucleophiles such as imidazoles, pyrazoles, benzimidazoles, indazole, 1,2,3-triazole, 1,2,4-triazole, and 1H-benzotriazole. Although these allenyl isothiocyanates are very reactive electrophiles and tend to polymerize, the
通过几种异戊烯基异硫氰酸酯与亲核试剂如咪唑,吡唑,苯并咪唑,吲唑,1,2,3-三唑,1,2,4的反应,制备了在C-2位带有不同杂环系统的取代噻唑衍生物的新例子。 -三唑和1 H-苯并三唑。尽管这些烯丙基异硫氰酸酯是非常活泼的亲电子试剂,并且倾向于聚合,但是噻唑产物的产率介于中等和非常好的之间。反应的区域化学通过NMR和X射线研究证明,表明环境亲核试剂的攻击非常有选择地进行。然而,在某些情况下,产物形成为芳族杂环和非芳族异构体的混合物。后者可以重新排列以产生均匀的芳族噻唑。