title: Cooperative catalytic activation of Si-H bonds by a polar Ru-S bond: regioselective low-temperature C-H silylation of indoles under neutral conditions by a Friedel-Crafts mechanism.
abstract: Merging cooperative Si-H bond activation and electrophilic aromatic substitution paves the way for C-3-selective indole C-H functionalization under electronic and not conventional steric control. The Si-H bond is heterolytically split by the Ru-S bond of a coordinatively unsaturated cationic ruthenium(II) complex, forming a sulfur-stabilized silicon electrophile. The Wheland intermediate of the subsequent Friedel-Crafts-type process is assumed to be deprotonated by the sulfur atom, no added base required. The overall catalysis proceeds without solvent at low temperature, only liberating dihydrogen.
authors.affiliation: Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster, Germany.
authors.forename: Hendrik F T
authors.initials: HF
authors.lastname: Klare
authors.forename: Martin
authors.initials: M
authors.lastname: Oestreich
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Ito
authors.forename: Hisao
authors.initials: H
authors.lastname: Nishiyama
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ohki
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Tatsumi