title: Palladium-catalyzed direct desulfitative C2 arylations of 3-halo-N-protected indoles using (hetero)arenesulfonyl chlorides.
abstract: The direct arylation of N-protected 3-haloindole derivatives with benzenesulfonyl chlorides as coupling partners using 5 mol% of bis(acetonitrile)dichloropalladium(ii) catalyst and lithium carbonate as a base in 1,4-dioxane was investigated. We demonstrated that both iodo and chloro substituents at the indolyl C3 position act as temporary blocking groups allowing the formation of 2-arylindoles through a direct desulfitative arylation, followed by in situ dehalogenation. While, from 3-bromoindole derivatives, 2-aryl-3-bromoindoles were obtained without debromination, and could be converted into 2,3-diarylindoles through a second palladium coupling. This method allows one to prepare in a few steps a very wide variety of indole derivatives, which are of interest in the synthesis of bioactive molecules.
authors.affiliation: UMR 6226 CNRS-Université de Rennes 1 "Organométalliques, Matériaux et Catalyse", Campus de Beaulieu, 35042 Rennes, France. jean-francois.soule@univ-rennes1.fr henri.doucet@univ-rennes1.fr.
authors.forename: Anoir
authors.initials: A
authors.lastname: Hfaiedh
authors.forename: Hamed
authors.initials: H
authors.lastname: Ben Ammar
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Soulé
authors.forename: Henri
authors.initials: H
authors.lastname: Doucet