- C(sp3)-F bond activation of CF3-substituted anilines with catalytically generated silicon cations: Spectroscopic evidence for a hydride-bridged Ru-S dimer in the catalytic cycle
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Heterolytic splitting of the Si-H bond mediated by a Ru-S bond forms a sulfur-stabilized silicon cation that is sufficiently electrophilic to abstract fluoride from CF3 groups attached to selected anilines. The ability of the Ru-H complex, generated in the cooperative activation step, to intramolecularly transfer its hydride to the intermediate carbenium ion (stabilized in the form of a cationic thioether complex) is markedly dependent on the electronic nature of its phosphine ligand. An electron-deficient phosphine thwarts the reduction step but, based on the Ru-S catalyst, half of an equivalent of an added alkoxide not only facilitates but also accelerates the catalysis. The intriguing effect is rationalized by the formation of a hydride-bridged Ru-S dimer that was detected by 1H NMR spectroscopy. A refined catalytic cycle is proposed.
- Stahl, Timo,Klare, Hendrik F. T.,Oestreich, Martin
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supporting information
p. 1248 - 1251
(2013/03/29)
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- TRIFLUOROMETHYLATION OF AROMATIC AMINO AND THIO COMPOUNDS BY BISTRIFLUOROMETHYL TELLURIDE
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The reaction of aromatic and heterocyclic amines with (CF3)2Te gave the products from trifluoromethylation in the aromatic ring.The reaction with the corresponding thiols gave S-trifluoromethyl derivatives.
- Naumann, D.,Pazenok, S. V.,Turra, V.
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p. 128 - 130
(2007/10/02)
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- Photochemical Reactions of Substituted Benzenes with Aliphatic Amines
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The products arising from the irradiation of diethylamine and t-butylamine with toluene, chlorobenzene, anisole, benzonitrile, benzyl fluoride, benzotrifluoride (α,α,α-trifluorotoluene), m-fluorobenzotrifluoride (α,α,α,m-tetrafluorotoluene), p-fluorotoluene, m-fluorotoluene, p-fluoroanisole, m-fluoroanisole, and 1,3-bis(trifluoromethyl)benzene, and of triethylamine with toluene, benzotrifluoride and 1,3-bis(trifluoromethyl)benzene, all at 254 nm, are described.Reaction pathways involving both substitution and 1,2- and 1,4-acyclic addition processes are observed and which predominates depends upon the arene substituent.The novel acyclic adduct, Me2C=CH-CH=CH-CH=NBut, is obtained from toluene and t-butylamine and, contrary to previous reports, chlorobenzene yields arene-amine 1:1 adducts as well as the amine α-substitution product (16); benzonitrile gives aniline derivatives with the primary and secondary amines.
- Gilbert, Andrew,Krestonosich, Stefan,Westover, David L.
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p. 295 - 302
(2007/10/02)
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