164019-41-4Relevant academic research and scientific papers
Oxidative addition step in reactions involving palladium activation of carbon-halogen and carbon-oxygen bonds
Shmidt,Smirnov
, p. 495 - 501 (2008/10/09)
Different modifications of the Heck reaction involving the activation of carbon-halogen and carbon-oxygen bonds by palladium (styrene phenylation with iodobenzene or benzoic anhydride and iodobenzene carbonylation, reductive coupling, and reduction) are studied by in situ 31P NMR spectroscopy. The catalytic cycles of the reactions include oxidative addition to Pd(0) formed in situ. The product composition in this step depends strongly on the composition of the reaction mixture, which is related to PhX conversion in the main catalytic process and with the nature of the catalyst precursor. A new hypothesis as to the mechanism of the catalytic cycle in alkene arylation in the presence of phosphine ligands is suggested. This hypothesis is consistent with NMR monitoring data and with the value of the kinetic isotope effect.
The NMR study of the mechanism of alkene arylation with anhydrides of aromatic acids
Shmidt,Smirnov
, p. 195 - 198 (2008/10/08)
The main steps of the catalytic cycle of the alkene arylation reaction with the participation of anhydrides of aromatic acids as arylation agents were studied by 31P NMR spectroscopy. The catalytic cycle of the reaction included the steps of ox
Indirect formation of carboxylic acids via anhydrides in the palladium-catalyzed hydroxycarbonylation of aromatic halides
Grushin, Vladimir V.,Alper, Howard
, p. 4305 - 4315 (2007/10/02)
The carbonylation of [(Ph3P)2Pd2Ph2(μ-OH)2] (2) in the presence of PhI results in the quantitative formation of benzoic anhydride and [(Ph3P)2Pd2(PhCO)2(μ-I) 2] (3). This transformation contributes to some extent to the production of benzoic acid from haloarenes, CO, and alkali, catalyzed by [(Ph3P)2PdCl2], the latter being converted to 2 under the reaction conditions. Phenyl- and benzoylpalladium benzoates are likely key intermediates in the indirect formation of the acid, via the anhydride, by the carbonylation of 2. One such complex, [L2Pd(Ph)(PhCOO)] (5, L = Cy3P), was isolated from the carbonylation of [(Cy3P)2Pd2Ph2(μ-OH)2] (4) in hexane. The related complexes, [L2Pd2Ph2(μ-PhCOO)2] (6, L = PPh3; 7,L = PCy3), were prepared from benzoic acid and hydroxo complexes 2 and 4, respectively. Treatment of 6 and 7 with the corresponding phosphine afforded [L2Pd(Ph)(PhCOO)] (8, L = PPh3; 5,L = PCy3). When 6-8 were reacted with CO in benzene, benzoic anhydride was readily formed, whereas in the case of 5 both carbonylation and reductive elimination were sluggish. Crystallographic data for 6 (1:2 chloroform solvate): space group Pccn, a = 22.499(4) A?, b = 10.992(3) A?, c = 24.514(6) A?, V = 6062.4(23) A?3, Z = 4, R = 0.056, and Rw = 0.038.
