627-20-3Relevant academic research and scientific papers
ADSORPTION MEASUREMENTS DURING CATALYTIC ISOMERIZATION OF PENTENES AND 2-METHYL-1-PENTENE OVER KC24.
Tsuchiya,Yamamoto,Imamura
, p. 2037 - 2039 (1984)
The catalytic isomerization of pentenes over KC//2//4 has been investigated. The double-bond-migration and the cis-trans isomerization took place over KC//2//4, but the skeletal isomerization was not observed. From the rates of reactions and the selectivity ratios, all six of the relative rate constants and the activation energies of reactions were determined. The reaction paths on the triangular graph calculated from the rate constants show the cis-convex type profile. The competitive isomerization of 1-pentene and 2-methyl-1-pentene has also been investigated. The rate of isomerization of 1-pentene was greater than that of 2-methyl-1-pentene, which can be explained on the basis that the amount of chemisorption of 1-pentene during the competitive reaction is greater than that of 2-methyl-1-pentene.
Preference for structural versus geometric isomerization in the BCl3-catalyzed thermal isomerizations of gaseous 1,2-dimethylcyclopropane
Kalra, Bansi L.,Clark, Kimber G.,Lewis, David K.
, p. 263 - 264 (1988)
The thermal isomerization reactions of gaseous cis- and trans-1,2-dimethylcyclopropane have been studied in the presence and absence of boron trichloride, in a static reactor at 574 3, but the normally slower structural rearrangements become the dominant reactions in the presence of catalyst. Mechanistic implications are discussed.
SOLVENT EFFECTS ON THE ISOMERIZATION OF 1-PENTENE CATALYZED BY CATIONIC PLATINUM COMPLEXES
Kanai, Hiroyoshi,Hirako, Osamu
, p. 953 - 954 (1982)
The isomerization of 1-pentene with X (X=SO4H, ClO4) occurRed only in ethers.The decrease in the concentrations of 1-pentene and the platinum complexes leads to high cis-selectivity.
Designing and synthesis of phosphine derivatives of Ru3(CO)12 – Studies on catalytic isomerization of 1-alkenes
Pandya, Chayan,Panicker, Rakesh R.,Senjaliya, Parth,Hareendran, M.K. Hima,Anju,Sarkar, Sibasis,Bhat, Haamid,Jha, Prakash C.,Rao, Koya Prabhakara,Smith, Gregory S.,Sivaramakrishna, Akella
, (2021/01/12)
A comparative investigation on the isomerization reactions of 1-alkenes to their corresponding 2-alkenes catalyzed Ru3(CO)12 (1), Ru3(CO)9(PEt3)3 (2) and Ru3(CO)10(dppe) (3), (where dppe = 1,2-bis(diphenylphosphino)ethane) is described. Both the complexes of types 2 and 3 were characterized by all analytical and spectroscopic data. The molecular structure of 2 was confirmed by single-crystal X-ray analysis. It is observed that the nature of phosphine ligands plays an important role in the isomerization of 1-alkenes. When the chelated diphosphine is used, the internal isomerization reaction by [Ru3(CO)10(dppe)] (3) is completed relatively in less time compared to other derivatives. As per the DFT calculations, the observed reaction rate for the alkene isomerization may be explained based on the relative stability of 1, 2, and 3. The CO abstraction step is highly feasible in 3, the least stable among the three, thus the reaction occurs at the highest rate. Due to the increased relative stability from 2 to 1, the reaction requires more time at elevated temperatures and the rate decreases as a consequence.
CATALYTIC HYDROCARBON DEHYDROGENATION
-
Paragraph 0056; 0122; 0123, (2021/03/13)
A catalyst for dehydrogenation of hydrocarbons includes a support including zirconium oxide and Linde type L zeolite (L-zeolite). A concentration of the zirconium oxide in the catalyst is in a range of from 0.1 weight percent (wt. %) to 20 wt. %. The catalyst includes from 5 wt. % to 15 wt. % of an alkali metal or alkaline earth metal. The catalyst includes from 0.1 wt. % to 10 wt. % of tin. The catalyst includes from 0.1 wt. % to 8 wt. % of a platinum group metal. The alkali metal or alkaline earth metal, tin, and platinum group metal are disposed on the support.
C-F activation reactions at germylium ions: Dehydrofluorination of fluoralkanes
Braun, Thomas,Mei?ner, Gisa,Rachor, Simon G.,Talavera, Maria
supporting information, p. 4452 - 4455 (2020/05/13)
Reactions of the trityl cations with germanes afford the germylium ions [R3Ge][B(C6F5)4] (1a: R = Et, 1b: R = Ph, 1c: R = nBu). These compounds react with germane or fluorogermane to give polynuclear species, which are sources of the mononuclear ions, The latter convert with phosphines to yield the [R3Ge-PR3]+ (4a: R = Et, 4b: R = Ph) cations. Catalytic dehydrofluorination reactions were observed for the C-F bond activation of fluoroalkanes when using germanes as hydrogen source.
Carbonylative, Catalytic Deoxygenation of 2,3-Disubstituted Epoxides with Inversion of Stereochemistry: An Alternative Alkene Isomerization Method
Lamb, Jessica R.,Hubbell, Aran K.,MacMillan, Samantha N.,Coates, Geoffrey W.
supporting information, p. 8029 - 8035 (2020/05/01)
Reactions facilitating inversion of alkene stereochemistry are rare, sought-after transformations in the field of modern organic synthesis. Although a number of isomerization reactions exist, most methods require specific, highly activated substrates to achieve appreciable conversion without side product formation. Motivated by stereoinvertive epoxide carbonylation reactions, we developed a two-step epoxidation/deoxygenation process that results in overall inversion of alkene stereochemistry. Unlike most deoxygenation systems, carbon monoxide was used as the terminal reductant, preventing difficult postreaction separations, given the gaseous nature of the resulting carbon dioxide byproduct. Various alkyl-substituted cis- A nd trans-epoxides can be reduced to trans- A nd cis-alkenes, respectively, in >99:1 stereospecificity and up to 95% yield, providing an alternative to traditional, direct isomerization approaches.
Competitive adsorptions between thiophenic compounds over a CoMoS/Al2O3 catalyst under deep HDS of FCC gasoline
dos Santos, Alan Silva,Girard, Etienne,Leflaive, Philibert,Brunet, Sylvette
, p. 292 - 298 (2018/12/11)
The transformation of various model sulfur compounds (2-methylthiophene: 2MT, 3-methylthiophene: 3MT and benzothiophene: BT) representative of sulfur compounds in FCC gasoline was investigated over a CoMoS/Al2O3 catalyst. More specifically, a quantitative reactivity scale was established with BT being more reactive than 3MT and 2MT. In mixture, their reactivity was reduced due to the presence of the other sulfur compound, the scale of reactivity being preserved. BT strongly inhibits the transformation of 2MT. With a single kinetic model based on a Langmuir Hinshelwood formalism, kinetic and adsorption parameters were calculated and the results explained by mutual competitive adsorption between 2MT and BT with a higher adsorption constant for BT compared to that of 2MT.
Cobalt-Iron-Manganese Catalysts for the Conversion of End-of-Life-Tire-Derived Syngas into Light Terminal Olefins
Falkenhagen, Jan P.,Maisonneuve, Lise,Paalanen, Pasi P.,Coste, Nathalie,Malicki, Nicolas,Weckhuysen, Bert M.
supporting information, p. 4597 - 4606 (2018/03/06)
Co-Fe-Mn/γ-Al2O3 Fischer–Tropsch synthesis (FTS) catalysts were synthesized, characterized and tested for CO hydrogenation, mimicking end-of-life-tire (ELT)-derived syngas. It was found that an increase of C2-C4 olefin selectivities to 49 % could be reached for 5 wt % Co, 5 wt % Fe, 2.5 wt % Mn/γ-Al2O3 with Na at ambient pressure. Furthermore, by using a 5 wt % Co, 5 wt % Fe, 2.5 wt % Mn, 1.2 wt % Na, 0.03 wt % S/γ-Al2O3 catalyst the selectivity towards the fractions of C5+ and CH4 could be reduced, whereas the selectivity towards the fraction of C4 olefins could be improved to 12.6 % at 10 bar. Moreover, the Na/S ratio influences the ratio of terminal to internal olefins observed as products, that is, a high Na loading prevents the isomerization of primary olefins, which is unwanted if 1,3-butadiene is the target product. Thus, by fine-tuning the addition of promoter elements the volume of waste streams that need to be recycled, treated or upgraded during ELT syngas processing could be reduced. The most promising catalyst (5 wt % Co, 5 wt % Fe, 2.5 wt % Mn, 1.2 wt % Na, 0.03 wt % S/γ-Al2O3) has been investigated using operando transmission X-ray microscopy (TXM) and X-ray diffraction (XRD). It was found that a cobalt-iron alloy was formed, whereas manganese remained in its oxidic phase.
Alkanethiolate-capped palladium nanoparticles for selective catalytic hydrogenation of dienes and trienes
Chen, Ting-An,Shon, Young-Seok
, p. 4823 - 4829 (2017/10/19)
Selective hydrogenation of dienes and trienes is an important process in the pharmaceutical and chemical industries. Our group previously reported that the thiosulfate protocol using a sodium S-alkylthiosulfate ligand could generate catalytically active Pd nanoparticles (PdNP) capped with a lower density of alkanethiolate ligands. This homogeneously soluble PdNP catalyst offers several advantages such as little contamination via Pd leaching and easy separation and recycling. In addition, the high activity of PdNP allows the reactions to be completed under mild conditions, at room temperature and atmospheric pressure. Herein, a PdNP catalyst capped with octanethiolate ligands (C8 PdNP) is investigated for the selective hydrogenation of conjugated dienes into monoenes. The strong influence of the thiolate ligands on the chemical and electronic properties of the Pd surface is confirmed by mechanistic studies and highly selective catalysis results. The studies also suggest two major routes for the conjugated diene hydrogenation: the 1,2-addition and 1,4-addition of hydrogen. The selectivity between two mono-hydrogenation products is controlled by the steric interaction of substrates and the thermodynamic stability of products. The catalytic hydrogenation of trienes also results in the almost quantitative formation of mono-hydrogenation products, the isolated dienes, from both ocimene and myrcene.
