Oxidative Nucleophilic Substitution of Hydrogen versus Ring-Opening in the Reaction of 4-R-2-Nitrothiophenes with Amines. The Crucial Effect of 4-Alkyl Groups

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• 作者：Lara Bianchi ; Massimo Maccagno ; Giovanni Petrillo ; Fernando Sancassan ; Cinzia Tavani ; Stefano Morganti ; Egon Rizzato ; Domenico Spinelli
• 刊名：Journal of Organic Chemistry
• 出版年：2007
• 出版时间：July 20, 2007
• 年：2007
• 卷：72
• 期：15
• 页码：5771 - 5777
• 全文大小：116K
• 年卷期：v.72,no.15(July 20, 2007)
• ISSN：1520-6904

文摘

4-Alkyl-2-nitrothiophenes [10: R = CH₃, CH(OH)CH₃, CH(OCH₃)CH₃] react with secondary aliphaticamines, in the presence of AgNO₃, to give 3-alkyl-2-amino-5-nitrothiophenes (12) through an oxidativenucleophilic substitution of hydrogen (ONSH) of synthetic interest. This behavior is in striking contrastwith that of the parent 2-nitrothiophene (6), which was found to undergo ring-opening in analogousreaction conditions. A possible rationale for the crucial effect of alkyl groups is suggested, groundedalso on a study of the corresponding Meisenheimer-like adducts.