- Synthesis, Characterization, and Reactivity of Palladium Fluoroenolate Complexes
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Cross-coupling reactions of aryl groups with α-fluoro carbonyl compounds catalyzed by palladium complexes have been reported, but palladium fluoroenolate intermediates relevant to such reactions have not been isolated or even detected previously. We report the synthesis, structural characterization, and reactivity of a series of C-bound arylpalladium fluoroenolate complexes ligated by monophosphines and bisphosphines. DPPF-ligated arylpalladium fluoroenolate complexes (DPPF = 1,1-bis(diphenylphosphino)-ferrocene) derived from a monofluoroester, a difluoroester, difluoroamides, and difluoroacetonitrile underwent reductive elimination in high yields. Reductive elimination was faster from complexes containing less electron-withdrawing fluoroenolate groups and longer Pd-C(enolate) bonds than from complexes containing more electron-withdrawing fluoroenolate groups and shorter Pd-C(enolate) bonds. The rates of reductive elimination from these C-bound fluoroenolate complexes were significantly faster than those of the analogous trifluoromethyl complexes.
- Arlow, Sophie I.,Hartwig, John F.
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supporting information
p. 16088 - 16091
(2017/11/22)
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- Synthesis, X-ray, spectroscopic and a preliminary Suzuki coupling screening studies of a complete series of dppfMX2 (M=Pt, Pd; X=Cl, Br, I)
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A complete series of dppfMX2 (M=Pt, Pd; X=Cl, Br, I) compounds have been synthesized using different routes, and characterized fully. The synthesis of dppfPdI2 has been achieved by reacting Pd(COD)Cl2 with dppf in the presence of NaI. X-ray structures of dppfPdBr2 and dppfPdI2 have also been reported for the first time in this study. A preliminary Suzuki coupling screening study reveals that dppfPdX2 compounds are superior to the conventional Ph3P-based catalysts and bidentate phosphine-based ligands. Reactions carried out under in situ conditions also gave a similar trend, but their respective activities were much lower than that of the fully formed catalysts.
- Colacot, Thomas J.,Qian, Hu,Cea-Olivares, Raymundo,Hernandez-Ortega, Simon
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p. 691 - 697
(2007/10/03)
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