- Vinyl and carbene ruthenium(II) complexes from hydridoruthenium(II) precursors
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The reactions of the hydrido compounds [RuHCl(CO)(L)2] {L = PiPr3 (1), PCy3 (2)} with HC≡CR (R = H, Ph, tBu) afforded by insertion of the alkyne into the Ru-H bond the corresponding vinyl complexes [RuCl(CH=CHR)-(CO)(L)su
- Jung, Stefan,Brandt, Carsten D.,Wolf, Justin,Werner, Helmut
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p. 375 - 383
(2007/10/03)
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- Acid-promoted homogeneous hydrogenation of alkenes catalyzed by the ruthenium-hydride complex (PCy3)2(CO)(Cl)RuH: Evidence for the formation of 14-electron species from the selective entrapment of the phosphine ligand
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The addition of 1.0 equiv of HBF4·OEt2 led to a ca. 2-3-fold increase in the catalyst activity of (PCy3)2(CO)(Cl)RuH (1a) toward the hydrogenation of alkenes. The stoichiometric reaction of 1a with HBF4·OEt2 produced a 1:3.5 mixture of the new ruthenium-hydride species 2 and Cy3PH+BF4-. The catalyst activity of the isolated 2/Cy3PH+ mixture was found to be similar to 1a/HBF4·OEt2. The complex 2 slowly decomposed in C6H6 solution to give a novel tetrameric complex 3. The treatment of 1a with HBF4·OEt2 in CH3CN led to the selective formation of the monophosphine species 4, which was converted to the stable complex 5 upon treatment with excess PPh3. The reaction of 1a with a weak acid, HSiCl3, led to the formation of the anionic silyl complex 7. The structures of 3, 5, and 7 were determined by X-ray crystallography. The formation of η2-H2 complex 8 was observed by NMR at low temperature. These results suggested that the 14-electron species [(PCy3)(CO)RuHCl], generated from the selective entrapment of the phosphine ligand, is the key species involved in the catalytic hydrogenation reaction.
- Yi,Lee,He,Rheingold,Lam,Concolino
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p. 2909 - 2915
(2008/10/08)
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