3480-11-3Relevant articles and documents
PREPARATION OF α-QUATER-, α-SEXI, AND α-OCTITHIOPHENES
Nakayama, Juzo,Konishi, Toru,Murabayashi, Shigeru,Hoshino, Masamatsu
, p. 1793 - 1796 (1987)
α-Quaterthiophene (1), α-sexithiophene (2), and α-octithiophene (3) (the highest member of α-oligothiophenes ever synthesized) were prepared from α-bithiophene, α-terthiophene, and α-quaterthiophene, respectively, via monobromination with N-bromosuccinimide followed by reductive coupling reaction with an activated nickel(0) reagent.
Green halogenation of aromatic heterocycles using ammonium halide and hydrogen peroxide in acetic acid solvent
D'Aleo, Danielle N.,Allard, Sheena R.,Foglia, Cassandra C.,Parent, Shawna L.M.,Rohr, David J.,Gottardo, Christine,MacKinnon, Craig D.
supporting information, p. 679 - 683 (2013/08/23)
The green generation of X+ (X = Br, I) using hydrogen peroxide in aqueous acetic acid allows access to aromatic heterocyclic halides in yields and purities comparable to syntheses employing N-bromosuccinimide. In activated and unsubstituted thiophene rings, regioselectivity is quantitative for positions α to the sulfur; pyrroles also give quantitative reactions, at least initially. Deactivated rings, including furans and thiazoles, as well as thiophenes with strongly electron-withdrawing groups showed little to no reactivity under the conditions investigated. The reaction shows remarkable functional group tolerance (to alcohol, nitro, alkyl, halo, and carbonyl groups), as shown through reaction with substituted phenols. In all bromination reactions, reaction yields and regiochemistry were very similar to reactions involving N-bromosuccinimide in tetrahydrofuran solvent.
A novel method for the bromination of thiophenes
Arsenyan, Pavel,Paegle, Edgars,Belyakov, Sergey
scheme or table, p. 205 - 208 (2010/03/24)
A novel, fast and convenient method for the bromination of thiophenes and oligothiophenes with N-bromosuccinimide (NBS) using ultrasonic irradiation is elaborated. The yield of bromothiophenes strongly depends on the initial thiophene structure and nature of the solvent.