title: One-Pot Halogen Dance/Negishi Coupling of Dibromothiophenes for Regiocontrolled Synthesis of Multiply Arylated Thiophenes.
abstract: One-pot halogen dance/Negishi cross-coupling of readily available 2,5-dibromothiophenes is described. A lithium diisopropylamide (LDA)-mediated halogen dance reaction resulted in the formation of thermodynamically stable α-lithiodibromothiophenes, which were transmetalated with ZnCl2and subjected to Negishi cross-coupling to provide the corresponding arylated dibromothiophenes in one pot. The resultant β-bromo group was much less reactive than the remaining α-bromo group, which was used in a one-pot double Suzuki-Miyaura cross-coupling, enabling facile synthesis of multiply arylated thiophenes.
authors.affiliation: Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan. okano@harbor.kobe-u.ac.jp.
authors.forename: Kentaro
authors.identifier: http://orcid.org/0000-0003-2029-8505
authors.initials: K
authors.lastname: Okano
authors.affiliation: Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Sunahara
authors.affiliation: Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Yamane
authors.affiliation: Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Hayashi
authors.affiliation: Department of Chemical Science and Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
authors.forename: Atsunori
authors.initials: A
authors.lastname: Mori
keywords: cross-coupling; halogen dance; one-pot reaction; palladium; thiophene