共查询到20条相似文献,搜索用时 31 毫秒
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Light olefins such as ethylene and propylene are important industrial feedstocks, having essential applications in the production of plastics, ethylbenzene, and... 相似文献
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T. I. Akchurin N. Z. Baibulatova S. A. Grabovskii P. P. Talipova E. G. Galkin V. A. Dokichev 《Kinetics and Catalysis》2016,57(5):586-591
Palladium catalysts supported on a carbon–silica material were synthesized. Hydrogenation by molecular hydrogen was studied in the presence of straight-chain and cyclic olefins. As distinct from what is observed for olefins having a phenyl substituent, for aliphatic alkenes the reaction rate decreases with an increasing conversion due to the accumulation of hydrogenation products. The synthesized palladium catalysts show a higher hydrogenation activity than Pd/C. 相似文献
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Co- and ter-polymerization of ethylene with Fischer-Tropsch derived olefins having odd carbon number and branched olefins are investigated. A method of preparation of a robust, high productivity Ziegler-Natta catalyst suitable for ethylene co-polymerization with Fischer Tropsch olefin is reviewed. In supporting titanium tetrachloride, an attempt was made to control the titanium oxidation state. The resulting experimental data were fitted to a sub-sites model that associates titanium oxidation state with catalyst activity. 相似文献
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R. Rumin 《Journal of organometallic chemistry》1983,247(3):351-356
The chloro-bridged platinum(II) complex dichlorobis(2,4,6-trimethylpyridine)-platinum was found to be an active catalyst for homogeneous hydrogenation and hydrosilylation of olefins and α,β-unsaturated aldehydes and ketones at room temperature and under atmospheric pressure. Hydrosilylation of terminal olefins can be achieved with dimethylphenylsilane and a catalyst/reactant ratio of 10?6/1. This complex is the first example of a platinum(II) compound containing pyiridine ligands having good catalytic activity possibilities. 相似文献
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Shigeo Katsumura Keiko Hori Shinya Fujiwara Sachihiko Isoe 《Tetrahedron letters》1985,26(38):4625-4628
Regiospecific synthesis of substituted γ-hydroxybutenolide was accomplished by photosensitized oxygenation of 2-trimethylsilyl-furan derivatives, and chemoselective oxidation of furan ring having tri- and tetra-substituted olefins in the side chain was also achieved. 相似文献
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The first stereoselective method of preparation of (E)-dienol phosphates from alpha,beta-ethylenic aldehydes is described. The key point is the stereoselective enolization of conjugated alkenals by potassium tert-butoxide in the presence of N-methylpyrrolidinone (NMP). 相似文献
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Eigoro Murayama Masahiro Uematsu Hiroyuki Nishio Tadashi Sato 《Tetrahedron letters》1984,25(3):313-316
Internal reaction of secondary alkyltin(IV) compounds having thionium ion gave internal trans olefins with high yield and regio- and stereoselectivity via 1,5- or 1,6-transfer of a hydride β to the trialkylstannyl group. 相似文献
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In the biosynthesis of a polyether ionophore antibiotic, lasalocid A, the cyclic ether skeleton composed of a tetrahydrofuran linked to a tetrahydropyran could be constructed by oxidative cyclization of linear dodecaketide diene precursor. Hence, we hypothesized a prelasalocid having (E,E)-trisubstituted olefins as the dodecaketide biosynthetic precursor. A stereo-controlled synthetic route to the prelasalocid has been devised in a highly convergent manner entailing installation of a variety of substituents at the trisubstituted olefins. 相似文献
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Mikami K Yusa Y Hatano M Wakabayashi K Aikawa K 《Chemical communications (Cambridge, England)》2004,(1):98-99
A cationic rhodium(I) complex having a skewphos ligand is shown to be a highly enantioselective catalyst for asymmetric carbocyclization of 1,6-enynes with tri-substituted olefins to control quaternary stereogenic centers of spiro-rings. 相似文献
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Koichi Mikami Yukinori Yusa Manabu Hatano Kazuki Wakabayashi Kohsuke Aikawa 《Tetrahedron》2004,60(20):4475-4480
A tropos rhodium(I) complex having skewphos ligand is shown to be a highly enantioselective catalyst for asymmetric ene-type carbocyclization of 1,6-enynes with tri-substituted olefins to control quaternary stereogenic centers or spiro-rings. 相似文献
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Many β-alkyl- and β-arylpropionic acids are readily obtainable by the reaction of secondary or tertiary alcohols, esters of these, or olefins with the inexpensive 1, 1-dichloroethylene in sulfuric acid. The success of the synthesis depends on the bulk and energy of the carbonium ion intermediate formed from the alcohols or olefins. With carbonium ions having one H atom attached to the carbonium C atom, electrophilic substitution of the 1,1-dichloroethylene takes place to a small extent. Dicarboxylic acids and carboxylic acids with higher molecular weights are sometimes formed as a result of side reactions. 相似文献
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Carbonyl olefination with a lithiomethane, having besides the group P(O)Ph2 at the methane C-atom an organo-heavy-metal group, occurs at low temperatures to give exclusively diphenylphosphoryl substituted olefins. 相似文献
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《Tetrahedron letters》1988,29(35):4437-4440
Reactions of nitrosonium hexafluorophosphate or tetrafluoroborate with olefins having aryl groups at an olefinic carbon atom at low temperature in acetonitrile afforded 4H-5,6-dihydro-1,2-oxazines with two aryl groups at C-4 and C-6 in fair to good yields. 相似文献
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The reaction of allyl carbamates with activated olefins in the presence of Pd(PPh3)4 catalyst in THF proceeded smoothly at room temperature to give the corresponding beta,alpha-bisadducts, beta-amino-alpha-allylated products, in high yields. Not only highly activated olefins containing two cyano groups but also 2-cyano enones underwent facile aza-Michael addition--allylation with various allylic carbamates giving the corresponding products in high yields and with high diastereoselectivities. The stereochemistry of the singly formed product was confirmed with the help of X-ray crystallographic technique. It is an excellent method for creating beta-amino alpha-allyl ketones having two contiguous stereocenters: quaternary carbon adjacent to secondary amine carbon center. 相似文献
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高分子负载金属络合物催化烯烃对映选择环氧化的研究 总被引:8,自引:0,他引:8
综述了近年来高分子负载金属络合物催化烯烃对映选择环氧化的研究进展,着重阐述了有机高分子和无机高分子负载金属络合物催化剂的催化活性,并就如何设计具有高催化活性和高对映选择性的高分子负载金属络合物催化剂提出了一些建议。 相似文献
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A new preparative method of β- and γ-alkoxy (acetoxy) ketones, which are important precursors of vinyl ketones and 1,4-diketones, respectively, is presented. With PdCl2/CuCl/O2 or PdCl2/p-benzoquinone catalyst system, internal olefins bearing allylic alkoxy or acetoxy group underwent regioselective oxidation to form the corresponding β-alkoxy or β-acetoxy ketones. Similarly, γ-acetoxy ketones were obtained from homoallyl acetates having internal olefins with high regioselectivity. 相似文献
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A flexible protocol for the synthesis of three lipophilic α-amino acid components of some novel cyclic peptides having important histone deacetylase inhibiting properties has been developed from a common source, which featured a cross-metathesis reaction between two unhindered terminal olefins as the key step. 相似文献
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《Tetrahedron letters》1987,28(39):4573-4574
When 1-bromo-4-acyloxybutanes having electron-withdrawing groups at 1-position, which were obtained by Cu(I)-catalyzed photochemical addition of 1-bromo-2-acyloxyethanes to electron-deficient olefins, were subjected to treatment with potassium t-butoxide, 2,7-dioxabicyclo[4.1.0] heptanes were obtained. 相似文献
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The complex [Ir(σ-carb)(CO)(PhCN)(PPh3)], where carb = -7-C6H5-1,2C2B10H10, was found to be an effective catalyst for homogeneous hydrogenation of terminal olefins and acetylenes at room temperature and atmospheric or subatmospheric hydrogen pressure. Internal olefins are not hydrogenated, but simple alk-1-enes are readily converted into the corresponding alkanes. Isomerization of the double bond catalyzed by the metal complex occurs at very small extent. Catalytic hydrogenation of olefins having carboxylate substituents on the unsaturated carbon atoms is prevented by the formation of thermally stable chelate hydridoalkyl complexes of the type I(σ-CHRCHR′C(O)OR″) (σ-carb)(CO)(PPh3)]. Acetylenes are hydrogenated to alkenes. The alk-1-enes formed in the hydrogenation of the alkynes HCCR in turn undergo the more slow reactions either of hydrogenation to alkanes or isomerization to internal olefins which cannot be further hydrogenated. Hydrogenation of alkynes of the type RCCR′ is stereospecifically cis, yielding cis- olefins. Catalyzed cis → trans isomerization reaction of these internal olefins occurs only to a negligeable extent. 相似文献