Direct functionalization of sp(2) C-H bonds via ortho diarylation of 2-pyridyl benzene with arylbromides was achieved using ruthenium(II) catalysts containing a RuCl2(NHC) unit and generated from [RuCl2(arene)](2) and two types of NHC precursors, pyrimidinium and benzimidazolium salts, in the presence of Cs2CO3. DFT calculations from RuCl2(NHC)(2-pyridylbenzene) show that a proton abstraction mechanism, on cooperative actions of both the coordinated base and the Ru(II) center, is favoured via a 13.7 kcal mol(-1) exothermic process affording an orthometalated intermediate with a 2.009 angstrom Ru-C bond.
C1 [Gourlaouen, Christophe; Maseras, Feliu] Inst Chem Res Catalonia ICIQ, Tarragona 43007, Spain.
[Gourlaouen, Christophe; Maseras, Feliu] Univ Autonoma Barcelona, Dept Quim, Bellaterra 08193, Catalonia, Spain.
[Ozdemir, Ismail; Demir, Serpil; Cetinkaya, Bekir] Inonu Univ, Fac Sci & Arts, Malatya, Turkey.
[Ozdemir, Ismail; Demir, Serpil; Cetinkaya, Bekir] Univ Ege, Fac Sci, Izmir, Turkey.
[Bruneau, Christian; Dixneuf, Pierre H.] Univ Rennes 1, Inst Sci Chim, F-35042 Rennes, France.