title: 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.
abstract: 4-Alkyl-2-nitrothiophenes [10: R = CH3, CH(OH)CH3, CH(OCH3)CH3] react with secondary aliphatic amines, in the presence of AgNO3, to give 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 adducts.
authors.affiliation: Dipartimento di Chimica e Chimica Industriale, Università di Genova, Via Dodecaneso 31, I-16146 Genoa, Italy.
authors.forename: Lara
authors.initials: L
authors.lastname: Bianchi
authors.forename: Massimo
authors.initials: M
authors.lastname: Maccagno
authors.forename: Giovanni
authors.initials: G
authors.lastname: Petrillo
authors.forename: Fernando
authors.initials: F
authors.lastname: Sancassan
authors.forename: Cinzia
authors.initials: C
authors.lastname: Tavani
authors.forename: Stefano
authors.initials: S
authors.lastname: Morganti
authors.forename: Egon
authors.initials: E
authors.lastname: Rizzato
authors.forename: Domenico
authors.initials: D
authors.lastname: Spinelli