New Facile Tandem Route to Oxo- and Thioxo[1,2,4]triazolo[1,5-<i>a</i>]pyridinium Salts
作者:Roberta Palkó、Zsuzsanna Riedl、Orsolya Egyed、László Fábián、György Hajós
DOI:10.1021/jo061361l
日期:2006.9.1
5-b]pyridinium salts (1), participate in 1,3-dipolar cycloaddition with aryl isothiocyanates and aryl isocyanates to result in formation of fused thioxo- and oxo[1,2,4]triazolium salts (5 and 12), respectively. This transformation is interpreted as a regular 1,3-cycloaddition followed by spontaneous elimination of the aryl- or benzylsulfanyl group. Formation of these triazolium salts can be followedunder
2-芳硫基吡啶基和苄基硫基吡啶鎓N-芳基酰亚胺(2),可轻松从四唑并[1,5- b ]吡啶鎓盐(1)中获得,与芳基异硫氰酸酯和芳基异氰酸酯一起参与1,3-偶极环加成反应,从而形成稠合的硫代[1,2,4]三唑鎓盐和氧代[1,2,4]三唑鎓盐(分别为5和12)。该转化被解释为常规的1,3-环加成,然后自发消除芳基-或苄基硫烷基。这些三唑鎓盐的形成可在适当的反应条件下通过开环反应进行,以提供一些新的三唑基烯基(6)。沿着路径1 → 5识别硫醇根阴离子的中间参与,使得可以简化一个简单的步骤至5,暗示串联反应序列。