Nucleophilic substitution of hydrogen (SNH) in 1,2,3-triazole 1-oxides in the synthesis of pentafluorophenylated azaheterocycles
摘要
Nucleophilic substitution of hydrogen (SNH) in 2-aryl-1,2,3-triazole 1-oxides proceeds by treatment with pentafluorophenyllithium according to the addition—elimination scheme (SNH AE) with the formation of the corresponding 4-pentafluorophenyl-1,2,3-triazoles with yield 72–78%. Calculation methods (determining the Fukui function and Gibbs energy) were used to establish that the presence of electron-withdrawing groups in the triazole ring does not increase the yield of the target product. Most likely, this can be explained by the shielding of the reaction center by electron clouds of conjugated nitrogen atoms.