15840-96-7Relevant articles and documents
Kinetics of cyclohexene hydrocarbalkoxylation with cyclohexanol catalyzed by the Pd(PPh3)2Cl2-PPh3-p- toluenesulfonic acid system
Aver'yanov,Sevost'yanova,Batashev
, p. 287 - 295 (2008)
The reaction kinetics of cyclohexene hydrocarbalkoxylation with cyclohexanol catalyzed by the Pd(PPh3)2Cl 2-PPh3-p-toluenesulfonic acid system was studied over the temperature range 363-393 K. The reaction rate was found to be a nonlinear function of the Pd(PPh3)2Cl2 concentration or a nonmonotonic function of the PPh3 and cyclohexanol concentrations or p CO. The experimental data were interpreted in terms of a mechanism that involves ion pairs containing alkyl and acyl palladium complexes of the cationic type as intermediates. Based on the quasi-steady-state approximation, a rate equation was obtained to adequately describe the experimental data. The rate equation parameters were estimated using the least squares technique. The apparent activation energies of these parameters were determined. The heats of formation of Pd(PPh3)2(C6H11OH) 2, Pd(PPh3)2(CO)2, and Pd(PPh 3)4 complexes from Pd(PPh3)2(C 6H5CH3)2 were estimated. A symbatic change in these values with the donor-acceptor properties of ligands was demonstrated.
Effect of pretreatment conditions on acidity and dehydration activity of CeO2-MeOx catalysts
Cronauer, Donald C.,Góra-Marek, Kinga,Garcia, Richard,Gnanamani, Muthu Kumaran,Jacobs, Gary,Kropf, A. Jeremy,Marshall, Christopher L.
, (2020/07/10)
A series of MeOx-modified CeO2 (CeO2-MnOx, CeO2-ZnO, CeO2-MgO, CeO2-CaO, and CeO2-Na2O) catalysts were prepared by the impregnation of CeO2 with corresponding metal nitrates. Acidity and oxidation state of cerium were investigated on both oxidized and reduced catalysts by employing Fourier Transform Infrared spectroscopy (FTIR) on adsorbed pyridine and in situ H2-Temperature Programmed Reduction/X-ray Absorption Spectroscopy (H2-TPR/XAS) techniques, respectively. Metal oxide addition tended to alter both type and number of acid sites on ceria. EXAFS data showed a significant difference in NCe-O between unmodified and CeO2-MeOx, suggesting that added MeOx interferes with vacancy formation on ceria during reduction. In comparison with air-pretreated samples, H2-pretreated ones under similar conversion of 1,5 pentanediol exhibited a higher selectivity towards linear alcohols. Alcohol conversion found to correlate with total acidity (i.e., Br?nsted and Lewis). CeO2 benefited from the addition of alkali (Na) or alkaline earth metals (Mg, Ca) by producing unsaturated alcohols.
Copper-Catalyzed Alkoxycarbonylation of Alkanes with Alcohols
Li, Yahui,Wang, Changsheng,Zhu, Fengxiang,Wang, Zechao,Dixneuf, Pierre H.,Wu, Xiao-Feng
, p. 1341 - 1345 (2017/04/14)
Esters are important chemicals widely used in various areas, and alkoxycarbonylation represents one of the most powerful tools for their synthesis. In this communication, a new copper-catalyzed carbonylative procedure for the synthesis of aliphatic esters from cycloalkanes and alcohols was developed. Through direct activation of the C sp3 ?H bond of alkanes and with alcohols as the nucleophiles, the desired esters were prepared in moderate-to-good yields. Paraformaldehyde could also be applied for in situ alcohol generation by radical trapping, and moderate yields of the corresponding esters could be produced. Notably, this is the first report on copper-catalyzed alkoxycarbonylation of alkanes.
On the understanding of BF3·Et2O-promoted intra- and intermolecular amination and oxygenation of unfunctionalized olefins
Yang, Chun-Hua,Fan, Wen-Wen,Liu, Gong-Qing,Duan, Lili,Li, Lin,Li, Yue-Ming
, p. 61081 - 61093 (2015/08/03)
BF3·Et2O was found to be effective for both intra- and intermolecular amination and oxygenation of unfunctionalized olefins. In the presence of 3 equiv. of BF3·Et2O, intramolecular hydroamination of N-(pent-4-enyl)-p-toluenesulfonamides, N-(hex-5-enyl)-p-toluenesulfonamides, intermolecular hydroamination between sulfonamides and cyclohexene, norbornene or styrene, lactonization of pent-4-enoic acid or hex-5-enoic acid compounds and esterification of cyclohexene with different carboxylic acids all proceeded readily, leading to the corresponding amination or oxygenation products in up to 99% isolated yields. Preliminary NMR experiments and DFT calculations suggested that the intramolecular hydroamination reactions proceeded via a sulfonimidic acid intermediate (N=S-OH), and formation of the corresponding Bronsted acid HF or HBF4 was less likely.
