title: Butadienic building blocks from 2-nitrothiophene as precursors of nitrogen heterocycles: intriguing dichotomic behavior.
abstract: With the goal of their exploitation for the synthesis of heterocycles, sulfides 10 and sulfones 11, derived from the initial ring-opening of 2-nitrothiophene (5) with pyrrolidine/AgNO3 in EtOH, were reacted with diazomethane. Interesting dichotomic behavior was found to yield pyrazolines 17 from 10 and isoxazolines 18 (as the main products) from 11. Intriguingly enough, in the latter case, an unexpected apparent C-C methylene insertion was also observed, leading to the homologous cyclopropanes 19 as secondary products.
authors.affiliation: Dipartimento di Chimica e Chimica Industriale, Università di Genova, Via Dodecaneso 31, I-16146, Genova, Italy.
authors.forename: Lara
authors.initials: L
authors.lastname: Bianchi
authors.forename: Gianluca
authors.initials: G
authors.lastname: Giorgi
authors.forename: Massimo
authors.initials: M
authors.lastname: Maccagno
authors.forename: Giovanni
authors.initials: G
authors.lastname: Petrillo
authors.forename: Valeria
authors.initials: V
authors.lastname: Rocca
authors.forename: Fernando
authors.initials: F
authors.lastname: Sancassan
authors.forename: Carlo
authors.initials: C
authors.lastname: Scapolla
authors.forename: Elda
authors.initials: E
authors.lastname: Severi
authors.forename: Cinzia
authors.initials: C
authors.lastname: Tavani