نتایج جستجو برای: light olefins

تعداد نتایج: 399881  

Journal: :Catalysis Today 2021

The production of base chemicals such as olefins and aromatics from synthesis gas is great interest both an academic industrial point view. We prepared a bulk iron Fischer Tropsch catalyst promoted with potassium capable converting to combined it H-ZSM-5 zeolite convert the formed on acid sites. All experiments were performed in stacked bed mode avoid migration promoters zeolite, which can deac...

Journal: :Organic & biomolecular chemistry 2014
Shuang Yang Shou-Fei Zhu Na Guo Song Song Qi-Lin Zhou

A carboxy-directed asymmetric hydrogenation of α-alkyl-α-aryl terminal olefins was developed by using a chiral spiro iridium catalyst, providing a highly efficient approach to the compounds with a chiral benzylmethyl center. The carboxy-directed hydrogenation prohibited the isomerization of the terminal olefins, and realized the chemoselective hydrogenation of various dienes. The concise enanti...

Journal: :Journal of the American Chemical Society 2011
Smaranda C Marinescu Daniel S Levine Yu Zhao Richard R Schrock Amir H Hoveyda

Monoaryloxide-pyrrolide (MAP) complexes of molybdenum were employed for the selective ethenolysis of 1,2-disubstituted Z olefins in the presence of the corresponding E olefins. Reactions were performed in the presence of 0.02-3.0 mol % catalyst at 22 °C under 20 atm ethylene. We have demonstrated that the Z isomer of an easily accessible E:Z mixture can be destroyed through ethenolysis and the ...

Journal: :Synlett : accounts and rapid communications in synthetic organic chemistry 2009
Chun-Yu Ho Kristin D Schleicher Timothy F Jamison

Recent advances using nickel complexes in the activation of unactivated monosubstituted olefins for catalytic intermolecular carbon-carbon bond-forming reactions with carbonyl compounds, such as simple aldehydes, isocyanates, and conjugated aldehydes and ketones, are discussed. In these reactions, the olefins function as vinyl- and allylmetal equivalents, providing a new strategy for organic sy...

Journal: :Journal of the American Chemical Society 2012
Nathan T Jui Jeffrey A O Garber Fernanda Gadini Finelli David W C MacMillan

A new method to rapidly generate pyrrolidines via a SOMO-activated enantioselective (3 + 2) coupling of aldehydes and conjugated olefins has been accomplished. A radical-polar crossover mechanism is proposed wherein olefin addition to a transient enamine radical cation and oxidation of the resulting radical furnish a cationic intermediate which is vulnerable to nucleophilic addition of a tether...

Journal: :Organic letters 2016
Adam M Johns Tonia S Ahmed Bradford W Jackson Robert H Grubbs Richard L Pederson

The first kinetically controlled, highly trans-selective (>98%) olefin cross-metathesis reaction is demonstrated using Ru-based catalysts. Reactions with either trans or cis olefins afford products with highly trans or cis stereochemistry, respectively. This E-selective olefin cross-metathesis is shown to occur between two trans olefins and between a trans olefin and a terminal olefin. Addition...

Journal: :Oil & Gas Science and Technology – Revue d’IFP Energies nouvelles 2021

The effects of nanocatalyst composition and calcination parameters on the performance Fe–Mn–Ce ternary nanocatalysts supported alumina granules in a laboratory fixed bed microreactor have been evaluated. Nanocatalysts were synthesized by incipient wetness impregnation under vacuum method (simultaneous metal species). samples used for hydrogenation carbon monoxide via Fischer-Tropsch synthesis. ...

2006
David Lesthaeghe Bart De Sterck Veronique Van Speybroeck Guy B. Marin Michel Waroquier

Light olefins, which are vital components for the petrochemical industry, are traditionally obtained through the refinement of crude oil. However, the rapidly increasing demand of oil-based chemicals calls for the development of new technologies based on alternative natural sources. Among these processes, the methanol-to-hydrocarbons (MTH) technology is one of the most promising and currently e...

2002
Gaurav Chaturvedi

The alkylation process is an important reaction used in refineries to upgrade light olefins and isobutene into a much more highly valued gasoline component. The primary alkylation reaction involves the reaction of isobutene with a light olefin such as butylenes, in the presence of strong acid catalyst to form the high octane. A problem of long standing is to determine the optimal operating cond...

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