نتایج جستجو برای: light olefins
تعداد نتایج: 399881 فیلتر نتایج به سال:
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...
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...
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 ...
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...
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...
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...
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. ...
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...
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...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید