A simple and novel methodology for the synthesis of 3-perfluoroalkylated-2H-indazole derivatives has been elaborated. The perfluoroalkylation of readily available 2-nitrobenzaldimines bearing electron donating groups was performed using the Ruppert-Prakash reagent and its analogues to afford α-difluoromethylated, α-trifluoromethylated and α-pentafluoroethylated benzylamines. A final reductive cyclization mediated by SnCl₂·2H₂O led to 2H-indazoles containing perfluoroalkyl groups via the generation of a new NN bond in moderate to good yields.

中文翻译：

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制备3-全氟烷基化2 H-吲唑衍生物的新策略

已经阐述了合成3-全氟烷基化的2- H-吲唑衍生物的简单新颖的方法。使用Ruppert-Prakash试剂及其类似物对带有供电子基团的2-硝基苯甲二胺进行全氟烷基化，得到α-二氟甲基化，α-三氟甲基化和α-五氟乙基化的苄胺。由SnCl ₂ ·2H ₂ O介导的最终还原性环化反应通过生成新的N N键，以中等至良好的收率生成了2个含H-吲唑的全氟烷基。