Reactivity of benzofuran and benzothiophene in palladium-catalysed direct C2,C3-diarylations

Karima Si Larbi (1, 2) , Safia Djebbar (2) , Jean-François Soulé (1) , Henri Doucet (1)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 LHCIM - Laboratoire d'hydrométallurgie et chimie inorganique moléculaire

The Pd-catalysed one pot direct diarylation of benzofuran and benzothiophene at both C2- and C3-positions was studied. In the presence of electron-deficient aryl bromides, the diarylation of benzofuran proceeded in good yields; whereas, with benzothiophene moderate yields were generally obtained, as the C3-position exhibits a poor reactivity. In order to obtain 2,3-diarylated benzothiophenes, its sequential arylation was examined. We found that the C3-arylation of benzothiophene followed by its C2-arylation provides a reliable methodology for the access to 2,3-diarylbenzothiophenes.

Keywords: palladium; catalysis; c-h bond functionalization; benzofuran; benzothiophene

Domains: Chemical Sciences; Organic chemistry

Karima Si Larbi, Safia Djebbar, Jean-François Soulé, Henri Doucet. Reactivity of benzofuran and benzothiophene in palladium-catalysed direct C2,C3-diarylations. Journal of Organometallic Chemistry, 2017, 843, pp.32-39. ⟨10.1016/j.jorganchem.2017.05.029⟩. ⟨hal-01559209⟩