title: C2-selective direct alkynylation of indoles.
abstract: The first C2-selective alkynylation of indoles using the hypervalent iodine reagent triisopropylsilylethynyl-1,2-benziodoxol-3(1H)-one (TIPS-EBX) with Pd(II) as a catalyst is described. This convenient and robust method gives a single-step access to substituted alkynyl indoles with very high C2 selectivity. The reaction is orthogonal to classical Pd(0) cross-coupling reactions, as it is tolerant to bromide and iodide substituents. The used silyl protecting group can be easily removed to give terminal acetylenes.
authors.affiliation: Laboratory of Catalysis and Organic Synthesis, Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL SB ISIC LCSO, BCH 4306, 1015 Lausanne, Switzerland.
authors.forename: Gergely L
authors.initials: GL
authors.lastname: Tolnai
authors.forename: Stephanie
authors.initials: S
authors.lastname: Ganss
authors.forename: Jonathan P
authors.initials: JP
authors.lastname: Brand
authors.forename: Jérôme
authors.initials: J
authors.lastname: Waser