نتایج جستجو برای: light olefin
تعداد نتایج: 400094 فیلتر نتایج به سال:
Light olefins such as ethylene, propylene, and butylenes, are basic building blocks for petrochemicals. Further, these olefins are also useful for production of clean fuels such as alkylates – which have high octanes but no sulfur, olefins, and aromatics – or as octaneenhancers such as ethers. The conventional olefin production process is steam cracking of C2−C4 light paraffins from natural gas...
the catalytic cracking of a fuel oil over fluid catalytic cracking (fcc) catalyst has been investigated applying different additives. catalyst mixtures consisting of a equilibrium fcc catalyst (e-cat) blended with zsm-5, mcm-41 and mordenite additives were examined at the additive levels of 25 wt.%. the catalytic performance of the matrix was studied in a fixed bed micro-activity test unit (mat...
The substitution chemistry of olefin complexes (silox)3M(ole) (silox = (t)Bu3SiO; M = Nb (1-ole), Ta (2-ole); ole = C2H4 (as 13C2H4 or C2D4), C2H3Me, C2H3Et, cis-2-C4H8, iso-C4H8, C2H3Ph, cC5H8, cC6H10, cC7H10 (norbornene)) was investigated. For 1-ole, substitution was dissociative (deltaG(double dagger)(diss)), and in combination with calculated olefin binding free energies (deltaG(o)(bind)), ...
The use of methanol over ZSM-5 and modified catalysts for the production light olefins has emerged as an effective new strategy this industry. In methanol-to-olefin (MTO) process, challenges are maintaining product selectivity prolonging lifetime catalyst manufacturing become
Enantioenriched secondary allylic carbamates have been deprotonated with sBuLi and reacted with boronic esters. In contrast to other electrophiles, high α-selectivity was observed and the boronate complexes were formed with almost complete retention of stereochemistry. The boronate complexes underwent a stereospecific 1,2-migration leading to tertiary allylic boronic esters with high er (>98:2)...
1-Phosphanorbornadiene derivatives were grafted onto various periodically organized mesoporous powders, including a new zirconia/silica mixed oxide synthesized by aerosol techniques. After complexation with the [Rh(CO)2]+ fragment, these materials were revealed to be more active in olefin hydrogenation than their homogeneous counterparts. The reasons for this higher activity are discussed in th...
The insertion of an olefinic C=C bond into a metal-carbon bond is of potential interest as a preparativeroute to new products and as results of C-C coupling reactions to organic compounds. The allyl compoundsof Mg, react with an olefin by inversion of the allyl group via a six center transition state. These precyclicreactions may be one of the most important classes of organic reactions. The re...
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 catalytic cracking of a fuel oil over fluid catalytic cracking (FCC) catalyst has been investigated applying different additives. Catalyst mixtures consisting of a equilibrium FCC catalyst (E-Cat) blended with ZSM-5, MCM-41 and Mordenite additives were examined at the additive levels of 25 wt.%. The catalytic performance of the matrix was studied in a fixed bed micro-activity test unit (MAT...
A highly selective olefin-assisted palladium-catalyzed oxidative carbocyclization via remote olefin insertion to afford cyclohexenes has been developed. It was shown that the assisting olefin moiety was indispensable for the formation of the cyclohexene product. Furthermore, preliminary studies on chiral anion-induced asymmetrical carbocyclization-borylation of enallenes have been carried out.
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