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@PHDTHESIS{Chen:802161,
      author       = {Chen, Junting},
      othercontributors = {Ritter, Tobias and Schoenebeck, Franziska and Bolm,
                          Carsten},
      title        = {{R}egio- und stereoselektive {T}hianthrenierung von
                      {O}lefinen zum {Z}ugang zu vielseitigen
                      {A}lkenylelektrophilen und {F}luorierung von
                      {A}rylthianthreniumsalzen},
      school       = {RWTH Aachen University},
      type         = {Dissertation},
      address      = {Aachen},
      reportid     = {RWTH-2020-09272},
      pages        = {1 Online-Ressource (xii, 250 Seiten) : Illustrationen,
                      Diagramme},
      year         = {2020},
      note         = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen
                      University; Dissertation, RWTH Aachen University, 2020},
      abstract     = {Direct C–H functionalization is one of the most
                      straightforward yet challenging strategies to quickly build
                      up functionalities from existing organic compounds.
                      Considering the ubiquitous existence of multiple C–H bonds
                      in one molecule, such as the coexistence of alkyl (sp3),
                      aryl/alkenyl (sp2) and alkynyl (sp) C–H bonds or several
                      with the same hybridization (aryl sp2 and alkenyl sp2),
                      functionalization with high positional selectivity is a
                      challenge. Typically, direct C–H functionalization
                      protocols can differentiate C–H bonds with different
                      hybridization (sp3 vs. sp2), yet there remains challenges
                      for site-selectivity especially when the target C–H bonds
                      have a similar chemical environment (e.g. ortho, meta, para
                      C–H bonds in one arene). In 2019, the Ritter group
                      reported a highly positional-selective C–H thianthrenation
                      of arenes with a broad substrate scope and high functional
                      group tolerance, and the resulting aryl thianthrenium salts
                      provide access to versatile functional groups via Pa
                      catalysis or photoredox chemistry. The work summarized in
                      this thesis describes one site-selective functionalization
                      of alkenes and one two-step site-selective fluorination of
                      arenes, both of which benefit from the site-selective C–H
                      thianthrenation reaction. Part I describes the development
                      of a method for regio- and stereoselective C–H
                      thianthrenation of alkenes. The reaction can be carried out
                      under ambient atmosphere without exclusion of air and
                      moisture and can be performed on a gram scale. For terminal
                      olefins, the reaction provides alkenyl thianthrenium
                      products with high stereoselectivity; the E isomers are
                      often the only isolable products. For internal olefins, the
                      double bond geometry maintains unchanged throughout the
                      thianthrenation reaction. Terminal olefins containing
                      structurally complex and highly functionalized moieties are
                      functionalized well. We isolated thianthrenium dicationic
                      bicycloadducts, which afforded the desired alkenyl
                      thianthrenium salts upon treatment with base; most likely
                      via an E1cBirr deprotonation mechanism. The resulting
                      alkenyl thianthrenium salts are good alkenyl electrophiles
                      in conventional palladium-catalyzed cross-coupling reactions
                      such as Negishi, Sonogashira and Heck reactions and
                      ruthenium-catalyzed (pseudo)halogenation.Part II describes
                      the development of a photoredox catalyzed fluorination
                      method for aryl thianthrenium (ArTT) salts, obtained from
                      site-selective C–H thianthrenation of arenes. The
                      substitution of aryl C–H bonds by thianthrene creates a
                      precursor, which readily engages in photoredox chemistry.
                      The C–H thianthrenation reaction tolerates a variety of
                      functional groups and was applied to the synthesis of
                      natural product derivatives. The photoredox properties of
                      aryl thianthrenium salts were established by cyclic
                      voltammetry, density functional theory studies, Hammett
                      analysis, and fluorescence quenching experiments. Subsequent
                      fluorination of ArTT species with fluoride under copper
                      mediation and photoredox catalysis (also termed as
                      metallophotoredox catalysis) provides pharmaceutically
                      relevant aryl fluorides as a single constitutional isomer in
                      a two-step sequence from the corresponding unfunctionalized
                      arenes.},
      cin          = {152310 / 150000},
      ddc          = {540},
      cid          = {$I:(DE-82)152310_20140620$ / $I:(DE-82)150000_20140620$},
      typ          = {PUB:(DE-HGF)11},
      doi          = {10.18154/RWTH-2020-09272},
      url          = {https://publications.rwth-aachen.de/record/802161},
}