3-alkyl-2-amino-5-nitrothiophenes (12) through an oxidative nucleophilic substitution of hydrogen (ONSH) of synthetic interest. This behavior is in striking contrast with that of the parent 2-nitrothiophene (6), which was found to undergo ring-opening in analogous reaction conditions. A possible rationale for the crucial effect of alkyl groups is suggested, grounded also on a study of the corresponding Meisenheimer-like
在AgNO 3的存在下,4-烷基-
2-硝基噻吩[ 10:R = CH 3,CH(OH)CH 3,CH(OCH 3)CH 3 ]与脂族仲胺反应,得到3-烷基-2 -
氨基-5-硝基
噻吩(12)通过合成目的氢的氧化亲核取代(ONSH)。该行为与母体
2-硝基噻吩(6)的行为形成鲜明对比,后者在类似的反应条件下发生开环。对于烷基的关键作用,提出了可能的基本原理,也基于对相应的迈森海默样加合物的研究。