F:Flammable;
110-62-3Relevant articles and documents
Highly regioselective and active rhodium/bisphosphite catalytic system for isomerization-hydroformylation of 2-Butene
Mo, Min,Yi, Tao,Zheng, Cong-Ye,Yuan, Mao-Lin,Fu, Hai-Yan,Li, Rui-Xiang,Chen, Hua
, p. 238 - 242 (2012)
The formation of linear aldehyde from isomerization-hydroformylation of 2-butene represents an important subject and current task in industry. Both high activity and excellent regioselectivity were achieved in the rhodium-catalyzed 2-butene isomerization-hydroformylation with 2,2′- bis(dipyrrolylphosphinooxy)-1,1′-(±)-binaphthyl (1) as ligand. Bulky phosphite with electron-withdrawing pyrrol groups dramatically improved the selectivity of linear product, and a good yield of 90.5% aldehydes was obtained with an excellent linear aldehyde regioselectivity of 95.3% under optimized condition. Graphical Abstract: Bulky phosphite with electron-withdrawing pyrrol groups dramatically improved the selective of linear product, and an excellent yield of 90.5% aldehydes with 95.3% regioselectivity of linear aldehyde was obtained in the Rh-catalyzed isomerization- hydroformylation of 2-butene in the presence of ligand 1.[Figure not available: see fulltext.]
Nitrenium ions in N-chloro-α-amino acids decomposition?
Armesto,Canle L.,Losada,Santaballa
, p. 1 - 8 (1993)
This article deals with the kinetics of decomposition of four isomers: N - Cl-(L)-2-Aminohexanoic acid, N - Cl-(L)-Leucine, N - Cl-(L)-Isoleucine, and N - Cl-(L)-tert-Leucine, in mild acid and basic aqueous solution. An alternative mechanism for this process which takes place through a nitrenium-like ion transition state is proposed. This mechanism is in consonance with the experimental data and with those available from the literature.
Tungsten Complex Catalyzed Dehydrative Decarboxylation of 2,3-Dihydroxycarboxylic Acids
Yu, Hye Kyung Bae,Schwartz, Jeffrey
, p. 6787 - 6790 (1992)
WOCl4 catalyzes dehydrative decarboxylation of 2,3-dihydrocarboxylic acids to enols, likely via β-lactone intermediates.Classical reagents for conversion of 3-hydroxycarboxylic acids to β-lactones fail with these substrates.
Highly regioselective homogeneous isomerization-hydroformylation of 2-butene with water- and air-stable phosphoramidite bidentate ligand
Tang, Songbai,Jiang, Yanxin,Yi, Jiwei,Duan, Xiaoxia,Fu, Haiyan,Li, Ruixiang,Yuan, Maolin,Chen, Hua,Yang, Chunji,Zheng, Xueli
, (2021)
Highly selective isomerization-hydroformylation of 2-butene was achieved with the presence of Rh(acac)(CO)2 and a phosphoramidite bidentate ligand which bearing 2,2′-dihydroxy-1,1′-binaphthyl backbone and N-indolyl substitute. The molar ratio of n- to isovaleraldehyde (217) is distinctly higher than the reported systems. NMR and IR revealed that the five-coordinate HRh(ligand)(CO)2 was an equatorial-equatorial configuration which contributed to the n-selectivity of valeraldehyde. The strong π-acceptor ability of ligand was suggested to play a key role in fast isomerization of 2-butene. Hydrolysis and oxidation experiments demonstrated that the ligand was water- and air-stable. Cyclic voltammetry measurement confirmed that this phosphoramidite ligand is more difficult to be oxidized, compared with the phosphine, phosphinite and phosphite ligands. Inspiringly, recycling experiments showed the catalytic system could work for at least 7 runs with unchanged selectivity.
Catalytic partial oxidation of cyclohexane in a single-gauze reactor
O'Connor,Schmidt
, p. 245 - 256 (2000)
C6H12 catalytic partial oxidation in a single-gauze reactor produced ~ 85% selectivity to olefins and oxygenates at 25% C6H12 conversion and 100% oxygen conversion, with cyclohexene and 5-hexenal as the dominant products. Experiments were performed with a 90% platinum-10% rhodium single gauze (~ 90-μm wire diameter) at C6H12/O2 molar ratios of 0.4-5, flow rates of 1-3 std L/min, preheat temperatures of 100°-300°C, N2 dilution from 5% to the air composition, and 1.2-2 atm. The C6H12/O2 ratio was the most important variable for operation of the single-gauze reactor because temperatures, reactant conversions, and product selectivities all changed significantly as C6H12/O2 was varied. Low dilution favored olefin production while high dilution suppressed the homogeneous reactions necessary for oxygenate formation. Oxygenates were also favored by high flow rates and low inlet temperatures. Higher reactor pressures (≤ 2 atm) increased the yield of cyclohexene and 5-hexenal and allowed complete oxygen conversion. Cyclohexanone was produced with 5% selectivity at C6H12/O2 ~ 4. Reaction pathways for C6H12 partial oxidation were hypothesized, and the products were consistent with the proposed surface-assisted gas-phase sequences.
Polymeric rhodium-containing catalysts in olefin hydroformylation
Slivinskii,Kolesnichenko
, p. 2449 - 2454 (2004)
The main results obtained by studying hydroformylation of olefins on polymeric rhodium-containing catalysts are reviewed. Different types of N-containing polymeric ligands capable of hydroformylating under conditions of heterogeneous catalysis are considered. Possibilities of using water-soluble polymers containing quaternary ammonium groups are shown. The data on the influence of a polymeric matrix on the catalytic properties of the rhodium catalyst of olefin hydroformylation are presented.
Copper mediated conversion of nitro compounds to aldehydes or ketones by dioxygen
Balogh-Hergovich, Eva,Kaizer, Jozsef,Speier, Gabor
, p. 573 - 574 (1996)
Primary and secondary nitro compounds are easily transformed to aldehydes or ketones by dioxygen catalyzed by metallic copper.
Delayed autocatalytic behavior of Mn(II) ions at a critical ratio: The effect of structural isomerism on permanganic oxidation of L-norleucine
Bahrami, Homayoon,Zahedi, Mansour
, p. 1 - 11 (2006)
The kinetics of the permanganic oxidation process of L-norleucine, L-leucine, L-isoleucine, and L-tert-leucine in strong acid medium has been investigated using a spectrophotometric technique. Conclusive evidences have proven autocatalytic activity of Mn(II) for these reactions in strong acid medium analogous to weak acid medium, but in the former, ratio of Mn(II) to amino acid concentration must reach a certain amount for autocatalytic phenomenon to emerge, which we call "critical ratio." This critical ratio depends on the nature of the amino acid employed. Thus considering "delayed autocatalytic behavior" of Mn(II) ions, rate equations satisfying observations for both catalytic and noncatalytic routes have been presented. Kinetic data in a noncatalytic pathway have been fitted to a biparametric equation including inductive, steric, and hyperconjugation correction effects, and it is determined that by shifting the side branch on a carbon chain toward an α-carbon atom (adjacent to amino acid's functional group) and also adding branches to the α-carbon atom, the reaction rate in the noncatalytic pathway decreases. Inductive and steric hindrance factors in amino acid's carbon chain are effective on processes' rate both in catalytic and noncatalytic pathways.
Combined synergetic and steric effects for highly selective hydrogenation of unsaturated aldehyde
Lan, Xiaocheng,Xue, Kaizhen,Wang, Tiefeng
, p. 49 - 60 (2019)
Enhancing the selectivity to unsaturated alcohols for the hydrogenation of unsaturated aldehydes is of great importance and challenge. Herein, Pt-SnOx@ZIF-8 catalysts with combined synergetic and steric effects were designed for the hydrogenation of 2-pentenal. The selectivity to unsaturated alcohol was enhanced from 4.3% to 61.5% by the synergetic effect between SnOx and Pt active sites and was further enhanced to 80.9% by the steric effect of ZIF-8. In situ FTIR was used to investigate the surface reaction mode over the present catalysts. The results showed that SnOx acted as electrophilic sites for the adsorption and activation of the C[dbnd]O bond and the apertures of ZIF-8 oriented the C[dbnd]O adsorption on the active sites.
Supported ionic liquid phase (SILP) catalyzed hydroformylation of 1-butene in a gradient-free loop reactor
Haumann, Marco,Jakuttis, Michael,Werner, Sebastian,Wasserscheid, Peter
, p. 321 - 327 (2009)
The supported ionic liquid phase (SILP) catalysis technology was applied to gas-phase hydroformylation of 1-butene using sulfoxantphos 1 modified rhodium complexes. Kinetic experiments were performed in a fixed bed reactor and compared to a gradient-free gas-phase loop reactor (Berty type). The influence of substrate concentration, temperature and syngas pressure was determined. Data from fixed bed and Berty reactor were found to be in good agreement with respect to activation energy and reaction order. Ex-situ NMR studies of fresh and used SILP catalysts confirmed that the ligand remained intact after prolonged time on stream.
