- Hydride route for the palladium-catalysed cyclocarbonylation of monoterpenes
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This paper focuses on the mechanism by which a monoterpene undergoes a cyclocarbonylation reaction catalysed by a palladium complex. Evidence is provided, based on intermediate species observed under pressure or with various ligands, that the catalytic cycle follows a hydride route starting from [Pd(H)(SnCl3)L2]. The [Pd(H)(SnCl3)L 2] complexes (L = PPh3 or PCy3) have been observed for the first time by multinuclear NMR spectroscopy. Cationic hydride complexes or palladium(0) precursors show either no or poor reactivity. Studies related to model platinum complex chemistry have detected an acylplatinum species. Most of the observations have been done on the cyclocarbonylation of isopulegol, dihydromyrcenol or isolimonene into the corresponding lactones or cyclopentanones. The use of dihydromyrcene allowed us to observe the acylplatinum complex and the corresponding elusive acylpalladium species. The co-catalytic role of SnCl2 is also demonstrated. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
- Nguyen, Duc Hanh,Laurenczy, Gabor,Urrutigoity, Martine,Kalck, Philippe
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p. 4215 - 4225
(2007/10/03)
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- [Pd(H)(SnCl3)L2]: The key active species in the catalyzed alkoxycarbonylation reaction of terminal alkenes
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The four complexes [Pd(H)(Cl)L2] and [Pd(H)(SnCl 3)L2], L = PPh3, PCy3, have been synthesized and fully characterized by multinuclear NMR. They represent the active species of the hydride palladium-catalyzed alkoxycarbonylation of terminal alkenes. Isolation of the model acylplatinum complex, resulting from the carbonylation of dihydromyrcene, clearly shows that SnCl2 as co-catalyst produces a SnCl3 ligand which modulates the metal center electron density.
- Nguyen, Duc Hanh,Coppel, Yannick,Urrutigo?ty, Martine,Kalck, Philippe
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p. 2947 - 2951
(2007/10/03)
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