- Degradation kinetics and solvent effects of various long-chain quaternary ammonium salts
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Surfactants such as quaternary ammonium salts (QAS) have been in increasing demand, for emerging new applications. Recent attempts at process intensification of their production have disclosed the need for a better understanding of QAS thermal stability. This work aims to determine the degradation kinetics of various QASs and the associated solvent?effects. The degradation kinetics of four methyl carbonate QASs were determined in various polar solvents in stainless steel batch autoclaves. (Formula presented.) H NMR spectrometry was employed for offline analysis of the reaction mixtures. The kinetic parameters were then used to compare the thermal stability of the four compounds in the polar solvents. Water showed no degradation, and methanol (MeOH) was the solvent that provided the second-best stability. Water–MeOH mixtures may provide an overall optimum. Moreover, and longer long-chain substituents increased the degradation?rate. Thermogravimetric analysis was used to obtain the thermal stability in a solid state, that is, solventless environment. Isoconversional analysis showed that no reliable kinetic parameters could be determined. Nevertheless, the data did allow for a comparison of the thermal stability of 14 different QASs. Furthermore, the relative instability of the compounds in the solid state demonstrated the challenges of solventless QAS?production.
- Kleijwegt, Roel J. T.,Winkenwerder, Wyatt,Baan, Wim,van der Schaaf, John
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- Controlling the Lewis Acidity and Polymerizing Effectively Prevent Frustrated Lewis Pairs from Deactivation in the Hydrogenation of Terminal Alkynes
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Two strategies were reported to prevent the deactivation of Frustrated Lewis pairs (FLPs) in the hydrogenation of terminal alkynes: reducing the Lewis acidity and polymerizing the Lewis acid. A polymeric Lewis acid (P-BPh3) with high stability was designed and synthesized. Excellent conversion (up to 99%) and selectivity can be achieved in the hydrogenation of terminal alkynes catalyzed by P-BPh3. This catalytic system works quite well for different substrates. In addition, the P-BPh3 can be easily recycled.
- Geng, Jiao,Hu, Xingbang,Liu, Qiang,Wu, Youting,Yang, Liu,Yao, Chenfei
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p. 3685 - 3690
(2021/05/31)
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- ACYCLIC CARBENE LIGAND FOR RUTHENIUM COMPLEX FORMATION, RUTHENIUM COMPLEX CATALYST, AND USE THEREOF
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Provided are a novel acyclic carbene ligand for ruthenium complex formation; a ruthenium complex catalyst using the ligand; a method of using the complex as a catalyst in an ethylene-metathesis ethenolysis reaction; a method of preparing the ruthenium complex catalyst; and a method of preparing a linear alpha-olefin, the method including the step of reacting a linear or cyclic alkene compound in the presence of the ruthenium complex catalyst. The acyclic carbene ligand of the present invention and the ruthenium complex catalyst using the same have high selectivity and turnover number for terminal olefin formation in an ethylene-metathesis ethenolysis reaction, and thus linear α-olefins may be prepared with a high yield.
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Paragraph 0124-0130
(2021/05/14)
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- Influence of the pendant arm in deoxydehydration catalyzed by dioxomolybdenum complexes supported by amine bisphenolate ligands
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Dioxomolybdenum complexes supported by aminebisphenolate ligands were evaluated for their potential in catalyzing the deoxydehydration (DODH) reaction to establish structure-activity relationships. The nature of the pendant arm in these aminebisphenolate ligands was found to be crucial in determining reactivity in the deoxydehydration of styrene glycol (1-phenyl-1,2-ethanediol) to styrene. Pendant arms bearing strongly coordinating N-based groups such as pyridyl or amino substituents were found to hinder activity while those bearing non-coordinating pendant arms (benzyl) or even weakly coordinating groups (an ether) resulted in up to 6 fold enhancement in catalytic activity. A dioxomolybdenum complex featuring an aminemonophenolate ligand derived from the aminebisphenolate skeleton also resulted in similar yield enhancements. Although aromatic solvents were found to be ideal for performing these catalytic reactions, polar solvents such as N,N-dimethylformamide (DMF) and N,N′-dimethylpropyleneurea (DMPU) were also suitable. The catalyst was found to maintain its structural integrity under the optimized conditions and could be recycled for a second catalytic run without loss of activity. With the activated substrate meso-hydrobenzoin, trans-stilbene was obtained in a 56% yield at 220 °C along with benzaldehyde (71%) suggesting that the diol is a competing reductant under these conditions. This journal is
- John, Alex,Lunn, Maiko J.,Silva, Israel,Siu, Timothy C.
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supporting information
p. 9933 - 9941
(2020/07/03)
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- A Cp-based Molybdenum Catalyst for the Deoxydehydration of Biomass-derived Diols
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Dioxo-molybdenum complexes have been reported as catalysts for the deoxydehydration (DODH) of diols and polyols. Here, we report on the DODH of diols using [Cp*MoO2]2O as catalyst (Cp*=1,2,3,4,5-pentamethylcyclopentadienyl). The DODH reaction was optimized using 2 mol % of [Cp*MoO2]2O, 1.1 equiv. of PPh3 as reductant, and anisole as solvent. Aliphatic vicinal diols are converted to the corresponding olefins by [Cp*MoO2]2O in up to 65 % yield (representing over 30 turnovers per catalyst) and 91 % olefin selectivity, which rivals the performance of other Mo-based DODH catalysts. Remarkably, cis-1,2-cyclohexanediol, which is known as quite a challenging substrate for DODH catalysis, is converted to 30 % of 1-cyclohexene under optimized reaction conditions. Overall, the mass balances (up to 79 %) and TONs per Mo achievable with [Cp*MoO2]2O are amongst the highest reported for molecular Mo-based DODH catalysts. A number of experiments aimed at providing insight in the reaction mechanism of [Cp*MoO2]2O have led to the proposal of a catalytic pathway in which the [Cp*MoO2]2O catalyst reacts with the diol substrate to form a putative nonsymmetric dimeric diolate species, which is reduced in the next step at only one of its Mo-centers before extrusion of the olefin product.
- Li, Jing,Lutz, Martin,Klein Gebbink, Robertus J. M.
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p. 6356 - 6365
(2020/11/30)
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- Vortex Fluidic Ethenolysis, Integrating a Rapid Quench of Ruthenium Olefin Metathesis Catalysts
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Ruthenium-catalysed ethenolysis occurs in a vortex fluidic device (VFD)-a scalable, thin-film microfluidic continuous flow process. This process takes advantage of the efficient mass transfer of gaseous reagents into the dynamic thin film of liquid. Also reported is the rapid quenching of the ruthenium-based olefin metathesis catalyst by the addition of a saturated solution of N-acetyl-l-cysteine in MeCN, as a convenient alternative to previously reported quenching methods.
- Pye, Scott J.,Chalker, Justin M.,Raston, Colin L.
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p. 1138 - 1143
(2020/08/27)
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- Nickel-catalyzed deoxygenation of oxiranes: Conversion of epoxides to alkenes
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Deoxygenation of epoxides takes place under the catalysis of nickel in the presence of diethylzinc as a deoxygenation agent to yield alkenes. Epoxides with a wide variety of substitution patterns are deoxygenated in this catalytic system to give terminal, 1,1-disubstituted, 1,2-disubstituted, trisubstituted, and tetrasubstituted alkenes in high yields. Reactions of 1,2-disubstituted epoxides we examined proceeded in an E-stereoselective manner. High compatibility with other functional groups through this transformation was also observed.
- Mori, Takamichi,Takeuchi, Yoshihito,Hojo, Makoto
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supporting information
(2020/01/24)
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- Method for Oligomerizing Ethylene
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The present invention relates to an oligomerization method of ethylene using a reactor equipped with a condenser, wherein the method comprises a step of pre-mixing a raw material composition at a low temperature, introducing the composition into the reactor, and inducing an ethylene oligomerization reaction at a low reaction pressure. According to the method of the present invention, it is possible to prepare an oligomer having excellent reaction activity and product selectivity, and even if the oligomerization reaction proceeds at a low pressure condition, energy consumption is reduced compared to a conventional heat removal method.COPYRIGHT KIPO 2020
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Paragraph 0054-0060
(2020/09/04)
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- Direct and Tandem Routes for the Copolymerization of Ethylene with Polar Functionalized Internal Olefins
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Transition metal catalyzed ethylene copolymerization with polar monomers is a highly challenging reaction. After decades of research, the scope of suitable comonomer substrates has expanded from special to fundamental polar monomers and, recently, to 1,1-disubstituted ethylenes. Described in this contribution is a direct and tandem strategy to realize ethylene copolymerization with various 1,2-disubstituted ethylenes. The direct route is sensitive to sterics of both the comonomers and the catalyst. In the tandem route, ruthenium-catalyzed ethenolysis can convert 1,2-disubstituted ethylenes into terminal olefins, which can be subsequently copolymerized with ethylene to afford polar functionalized polyolefins. The one-pot, two-step tandem route is highly versatile and efficient in dealing with challenging substrates. This work is a step forward in terms of expanding the substrate scope for transition metal catalyzed ethylene copolymerization with polar-functionalized comonomers.
- Chen, Min,Chen, Changle
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supporting information
p. 1206 - 1210
(2019/12/24)
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- A Method for preparing alpha-olefins from Biomass-derived fat and oil
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The present invention relates to a method for preparing alpha-olefins from biomass-derived fats and oils. According to the preparation method, all of the various saturated or unsaturated fatty acids in the biomass-derived fats and oils can be prepared into alpha-olefins, and a conventional problem that the saturated fatty acids do not participate in a reaction or a mixture is generated due to polyunsaturated fatty acids can be solved. Thus, the present invention can be advantageously used to prepare alpha-olefins from biomass.
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Paragraph 0191-0202; 0229-0232
(2020/09/22)
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- HIGHLY SELECTIVE ELECTROCHEMICAL HYDROGENATION OF ALKYNES
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Disclosed are electrochemical methods to prepare an alkane or an alkene, such as a cis- alkene, from an alkyne, or an alkane from an alkene. The method utilizes an electrochemical cell having a cathode and an anode and a reactor.
- -
-
Page/Page column 7; 15
(2020/10/20)
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- Synthesis and Activity of Six-Membered Cyclic Alkyl Amino Carbene-Ruthenium Olefin Metathesis Catalysts
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Ru-cyclic alkyl amino carbene (Ru-CAAC) olefin metathesis catalysts perform extraordinarily in metathesis macrocyclization and ethenolysis, but previous studies have been limited to the use of five-membered CAAC (CAAC-5) ligands. In this work, we synthesized a different group of ruthenium catalysts with more σ-donating and π-accepting six-membered CAAC (CAAC-6) ligands, and their metathesis activity was probed through initiation studies, ring-closing metathesis (RCM), cross-metathesis, and ethenolysis. These catalysts display higher initiation rates than analogous Ru-CAAC-5 complexes but demonstrate lower activity in RCM and ethenolysis.
- Grubbs, Robert H.,Samkian, Adrian E.,Virgil, Scott C.,Xu, Yan,Yoon, Ki-Young
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supporting information
(2020/02/27)
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- Improved preparation of an olefin metathesis catalyst bearing quaternary ammonium tag (FixCat) and its use in ethenolysis and macrocyclization reactions after immobilization on metal-organic framework (MOF)
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An optimized synthesis of a key intermediate Ru4 in substantially improved yield of 50% and in scale up to 1 gram was described. Such obtained Ru4 was quantitatively converted into useful quaternary ammonium tagged catalyst Ru1 (FixCat) and immobilized in a metal-organic framework (MOF). Next, two challenging applications, not studied previously with hybrid Ru1@MOF catalyst were attempted. In the case of the RCM reaction yielding a macrocyclic musk lactone, heterogeneous Ru1@MOF exhibited under high-dilution conditions high resistance towards unwanted C-C double bond migration, thus offering superior selectivity as compared to analogous homogeneous catalysts. In ethenolysis of ethyl oleate, Ru1@MOF exhibited only slightly better selectivity as compared to well-known general-purpose Hoveyda-Grubbs SIMes and SIPr catalysts, while it was not able to challenge the benchmark Bertrand-Hoveyda-Grubbs catalyst in this transformation.
- Milewski, Mariusz,Kajetanowicz, Anna,Grela, Karol
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- In a Quest for Selectivity Paired with Activity: A Ruthenium Olefin Metathesis Catalyst Bearing an Unsymmetrical Phenanthrene-Based N-Heterocyclic Carbene
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Robust, selective, and stable in the presence of ethylene, ruthenium olefin metathesis pre-catalyst, {[3-benzyl-1-(10-phenyl-9-phenanthryl)]-2-imidazolidinylidene}dichloro(o-isopropoxyphenylmethylene)ruthenium(II), Ru-3, bearing an unsymetrical N-heterocyclic carbene (uNHC) ligand, has been synthesized. The initiation rate of Ru-3 was examined by ring-closing metathesis and cross-metathesis reactions with a broad spectrum of olefins, showing an unprecendented selectivity. It was also tested in industrially relevant ethenolysis reactions of olefinic substrates from renewable feedstock with very good yields and selectivities.
- D?browski, Micha?,Grela, Karol,Trzybiński, Damian,Wo?niak, Krzysztof,Wyr?bek, Przemys?aw
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- SYNTHESIS OF STRAIGHT-CHAIN LEPIDOPTERAN PHEROMONES THROUGH ONE- OR TWO- CARBON HOMOLOGATION OF FATTY ALKENES
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Methods for the preparation of alkenes including insect pheromones are described. The methods include homologation reactions employing reagents such as 1,3-diesters, epoxides, cyanoacetates, and cyanide salts for elongation of starting materials and intermediates by one or two carbon atoms. The alkenes include insect pheromones useful in a number of agricultural applications.
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- Method for catalytically oxidizing primary alcohol into corresponding carboxylic acid and simultaneously co-producing corresponding alpha olefin
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The invention relates to a method for catalytically oxidizing primary alcohol into corresponding carboxylic acid and simultaneously co-producing corresponding alpha olefin. The method comprises the following steps: mixing primary alcohol shown as a substrate (I), a catalyst cobalt salt, a nitrogen-containing ligand and a solvent, refluxing and stirring for 4-48 hours in an oxygen or air atmospherewith a certain pressure, and distilling and separating the reacted liquid to obtain carboxylic acid shown as (II) and alpha olefin in a certain proportion. The cobalt salt catalyst used in the methodis cheap and easy to obtain, the used nitrogen-containing ligand is a commercial nitrogen-containing compound, the used oxidant is oxygen or air, the reaction condition is mild, and various primary alcohols can be converted into corresponding carboxylic acids and alpha olefins at a high conversion rate under the condition of low cost.
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Paragraph 0034-0035
(2020/12/30)
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- Deoxydehydration using a commercial catalyst and readily available reductant
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We have explored the use of a commercially available molybdenum compound, ammonium heptamolybdate (AHM) in catalyzing the deoxydehydration (DODH) reaction using sodium sulfite (Na2SO3) as reductant. The catalytic reactions were effected at relatively lower temperatures (170–190 °C) yielding the alkenes in moderate yields.
- Navarro, Christine A.,John, Alex
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p. 145 - 148
(2018/11/27)
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- Chromium complexes based on thiophene–imine ligands for ethylene oligomerization
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A new set of Cr(III) complexes, {L}CrCl3(THF), based on thiophene–imine (2a, L?=?PhOC6H4(N═CH)-2-SC4H3; 2b, L?=?PhOC2H4(N═CH)-2-SC4H3; 2c, L?=?Ph(NH)C2H4(N═CH)-2-SC4H3; 2d, L?=?PhOC6H4(N═CH)-2-SC4H2-5-Ph; 2e, L?=?Ph(NH)C2H4(N═CH)-2-SC4H2-5-Ph) have been prepared and characterized using elemental analysis and infrared spectroscopy. Upon activation with methylaluminoxane, all the chromium complexes generated active systems affording a nonselective distribution of α-olefins with turnover frequencies in the range 9500–93?500?(mol ethylene)?(mol Cr)?1?h?1, and producing mostly oligomers (95.0–99.3?wt% of total products). Small amounts of polymer were produced in these oligomerization reactions (0.8–8.2?wt%). The catalytic activities were quite sensitive to the ligand environment. Moreover, the effects of oligomerization parameters (temperature, [Al]/[Cr] molar ratio, time) on the activity and on the product distribution were examined.
- Ferreira, Jorge,Zilz, Raquel,Boeira, Igor S.,da Silva, Sabrina M.,Casagrande, Adriana C.A.,Casagrande, Osvaldo L.
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- α-Diphenylphosphino-N-(pyrazin-2-yl)glycine as a ligand in Ni-catalyzed ethylene oligomerization
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α-Diphenylphosphino-N-(pyrazin-2-yl)glycine was synthesized by the three-component condensation of diphenylphosphine, glyoxylic acid hydrate, and 2-aminopyrazine and its structure was confirmed by X-ray diffraction. It reacted with [Ni(COD)2] (COD is cycloocta-1,5-diene) to give complexes that were tested as catalysts for selective dimerization/oligomerization of ethylene to but-1-ene (main product) and C6–C14 α-olefins, respectively.
- Soficheva, Olga S.,Bekmukhamedov, Giyjaz E.,Dobrynin, Alexey B.,Heinicke, Joachim W.,Sinyashin, Oleg G.,Yakhvarov, Dmitry G.
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p. 575 - 577
(2019/11/02)
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- IONIC METAL ALKYLIDENE COMPOUNDS AND USE THEREOF IN OLEFINIC METATHESIS REACTIONS
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A compound of formula (I) wherein: M is selected from Mo or W; X is selected from O or NR5; R1 and R2 are independently selected from H, C1-6 alkyl, and aryl; C1-6 alkyl and aryl optionally being substituted with one or more of C1-6 alkyl, C1-6 alkoxy, and O-C6H5; R3 is selected from a nitrogen-containing aromatic heterocycle being bound to M via said nitrogen; and from halogen; R4 is an aryl oxy group being bound to M via said oxygen of said aryl oxy group; wherein said aryl group Ar of said aryl oxy group is bound to a group Cat such to form a cationic ligand Cat+-Z-ArO-, wherein Z is either a covalent bond or a linker; R5 is alkyl or aryl, optionally substituted.
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Paragraph 00195; 00214
(2019/12/25)
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- 1,5-Naphthyl-linked bis(imino)pyridines as binucleating scaffolds for dicobalt ethylene oligo-/polymerization catalysts: Exploring temperature and steric effects
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Six examples of dinuclear bis(imino)pyridine-cobalt(ii) complexes, [1,5-{2-(CMeN)-6-(CMeN(2,6-R12-4-R2-C6H2))C5H3N}2(C10H6)]Co2Cl4 (R1 = Me, R2 = H Co1; R1 = Et, R2 = H Co2; R1 = iPr, R2 = H Co3; R1 = Me, R2 = Me Co4; R1 = Et, R2 = Me Co5; R1 = CHPh2, R2 = Me Co6), have been prepared from the corresponding bis(tridentate) compartmental ligands (L1-L6) in reasonable yields. The molecular structures of Co3 and Co5 revealed two N,N,N-cobalt dichloride units to adopt anti-positions about the 1,5-naphthyl linking unit, with each cobalt center exhibiting a distorted trigonal bipyramidal geometry. On activation with either MAO or MMAO, Co1-Co6 were shown to promote both polymerization and oligomerization of ethylene with high overall activities (up to 1.03 × 107 gPE per·mol(Co) per·h for Co1/MAO at 70 °C). Curiously, on increasing the reaction temperature a larger proportion of polymer was noted, while at lower temperature an enhanced selectivity for oligomer was seen. In general, the oligomeric products displayed Schulz-Flory distributions with high selectivities for α-olefins (>99%). On the other hand, the highly linear polymers displayed narrow dispersities and comprised both fully saturated and unsaturated chain ends with the vinyl content (-CHCH2) found to rise with the reaction temperature. By modulating the steric hindrance exerted by the ortho-R1 substituents in the precatalyst, polyethylenes displaying a remarkably broad range of molecular weights could be obtained [from 4.52 kg mol-1 (R1 = Me) to 246.7 kg mol-1 (R1 = CHPh2)].
- Chen, Qiang,Suo, Hongyi,Zhang, Wenjuan,Zhang, Randi,Solan, Gregory A.,Liang, Tongling,Sun, Wen-Hua
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supporting information
p. 8264 - 8278
(2019/06/18)
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- Integrated extraction and catalytic upgrading of microalgae lipids in supercritical carbon dioxide
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Fatty acids from microalgae are attractive compounds for catalytic upgrading to chemicals, but their extraction often requires multi-step procedures and the use of various organic solvents. To relieve this bottleneck, we propose a straightforward approach of combined extraction and catalytic functionalization via olefin cross-metathesis (ethenolysis and butenolysis) in supercritical CO2 (scCO2). This is demonstrated for Phaeodactylum tricornutum microalgae biomass. ScCO2 at optimum conditions (90 °C, 620 atm, ρ(CO2) = 0.90 g mL-1) extracted the lipids selectively and quantitatively from previously disrupted cells, while organic solvent extraction for comparison additionally extracted polar diacylglycerides and chlorophylls. In a one-pot approach, olefin cross-metathesis of the unsaturated fatty acids (FA16:1, FA18:1 and FA20:5) by alkenolysis yielded the desirable mid-chain olefin and unsaturated ester products. The product spectrum compares to alkenolysis of individual model compounds in scCO2 as well as of separately scCO2 extracted microalgae oil. Both these ethenolysis and butenolysis proceed with conversions of more than 81% and high selectivities to the desired products. This biorefinery approach was further illustrated by the simultaneous extraction and catalytic isomerizing alkoxycarbonylation in scCO2.
- Zimmerer, Julia,Pingen, Dennis,Hess, Sandra K.,Koengeter, Tobias,Mecking, Stefan
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supporting information
p. 2428 - 2435
(2019/05/21)
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- A Gentler Touch: Synthesis of Modern Ruthenium Olefin Metathesis Catalysts Sustained by Mechanical Force
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Mechanochemical synthesis of nine contemporary ruthenium catalysts used for olefin metathesis is described, being the first reported example of formation of Ru carbene organometallic complexes in solid state. Three key organometallic transformations commonly used in the synthesis of the second and third generations of Ru catalysts in solution—phosphine ligand (PCy3) exchange with in situ formed N-heterocyclic carbene (NHC) ligand, PCy3 to pyridine ligand replacement, and benzylidene ligands interchange—were proved to work under mechanochemical conditions, affording the targets in high purity. Mechanochemical approach not only requires less amounts of organic solvent (null for synthesis, only for purification) and is scalable, but also allows for transformations that were reported impossible in the solution phase.
- Mukherjee, Nirmalya,Marczyk, Anna,Szczepaniak, Grzegorz,Sytniczuk, Adrian,Kajetanowicz, Anna,Grela, Karol
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p. 5362 - 5369
(2019/11/11)
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- Normal Alpha Olefin Synthesis Using Dehydroformylation or Dehydroxymethylation
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The present invention discloses processes for producing normal alpha olefins, such as 1-hexene, 1-octene, 1-decene, and 1-dodecene in a multistep synthesis scheme from another normal alpha olefin. Also disclosed are reactions for converting aldehydes, primary alcohols, and terminal vicinal diols into normal alpha olefins.
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Paragraph 0127; 0128; 0129; 0132; 0134
(2019/09/06)
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- Oxidative Dehydroxymethylation of Alcohols to Produce Olefins
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Catalyst compositions for the conversion of aldehyde compounds and primary alcohol compounds to olefins are disclosed herein. Reactions include oxidative dehydroxymethylation processes and oxidative dehydroformylation methods, which are beneficially conducted in the presence of a sacrificial acceptor of H2 gas, such as N,N-dimethylacrylamide.
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Paragraph 0063
(2019/09/06)
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- Specialized ruthenium olefin metathesis catalysts bearing bulky unsymmetrical NHC Ligands: Computations, synthesis, and application
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Second-generation ruthenium olefin metathesis catalysts were investigated with systematic variation of the unsymmetrical uNHC ligands. Depending on the uNHC steric bulk, the catalysts exhibited different activity and selectivity in metathesis reactions. DFT calculations and X-ray crystallographic data were used to understand the influence of uNHC ligand structure on the catalyst properties. Furthermore, the catalysts were examined in the context of reactions that are problematic for general-purpose Ru catalysts, including industrially important self-cross metathesis of α-olefins and ethenolysis of ethyl oleate.
- Ma?ecki, Pawe?,Gajda, Katarzyna,Gajda, Roman,Wo?niak, Krzysztof,Trzaskowski, Bartosz,Kajetanowicz, Anna,Grela, Karol
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p. 587 - 598
(2019/01/08)
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- Fluoro-imidazopyridinylidene Ruthenium Catalysts for Cross Metathesis with Ethylene
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A series of ruthenium metathesis catalysts bearing fluorinated imidazo[1,5-a]pyridin-3-ylidene carbenes (F-ImPy) were developed for ethenolysis (cross metathesis with ethylene) of methyl oleate. X-ray crystal structure analysis shows Ru-F interaction, and this fluorine substitution appears to be pivotal to have stable ImPy-Ru precatalysts. Ligand structure was varied for high catalyst activity and cross metathesis selectivity in ethenolysis reaction. F-ImPy-Ru catalysts showed high selectivity in ethenolysis of methyl oleate and thermal robustness under an ethylene atmosphere.
- Byun, Seunghwan,Seo, Huiyeong,Choi, Jun-Ho,Ryu, Ji Yeon,Lee, Junseong,Chung, Won-Jin,Hong, Sukwon
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supporting information
p. 4121 - 4132
(2019/10/16)
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- Formation of Enol Ethers by Radical Decarboxylation of α-Alkoxy β-Phenylthio Acids
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Enol ethers are formed by radical decarboxylation of α-alkoxy β-phenylthio acids via the corresponding Barton esters. The phenylthio acids were usually made by the known regioselective reaction of α,β-epoxy acids with PhSH in the presence of InCl3, followed by O-alkylation of the resulting alcohol. In one case, thiol addition to an α,β-unsaturated ethoxymethyl ester was used.
- Palanivel, Ashokkumar,Mubeen, Sidra,Warner, Thomas,Ahmed, Nayeem,Clive, Derrick L. J.
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p. 12542 - 12552
(2019/10/19)
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- Integrating Activity with Accessibility in Olefin Metathesis: An Unprecedentedly Reactive Ruthenium-Indenylidene Catalyst
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Access to leading olefin metathesis catalysts, including the Grubbs, Hoveyda, and Grela catalysts, ultimately rests on the nonscaleable transfer of a benzylidene ligand from an unstable, impure aryldiazomethane. The indenylidene ligand can be reliably installed, but to date yields much less reactive catalysts. A fast-initiating, dimeric indenylidene complex (Ru-1) is reported, which reconciles high activity with scaleable synthesis. Each Ru center in Ru-1 is stabilized by a state-of-the-art cyclic alkyl amino carbene (CAAC, C1) and a bridging chloride donor: the lability of the latter elevates the reactivity of Ru-1 to a level previously attainable only with benzylidene derivatives. Evaluation of initiation rate constants reveals that Ru-1 initiates >250× faster than indenylidene catalyst M2 (RuCl2(H2IMes)(PCy3)(Ind)), and 65× faster than UC (RuCl2(C1)2(Ind)). The slow initiation previously regarded as characteristic of indenylidene catalysts is hence due to low ligand lability, not inherently slow cycloaddition at the Ru=CRR′ site. In macrocyclization and "ethenolysis" of methyl oleate (i.e., transformation into α-olefins via cross-metathesis with C2H4), Ru-1 is comparable or superior to the corresponding, breakthrough CAAC-benzylidene catalyst. In ethenolysis, Ru-1 is 5× more robust to standard-grade (99.9%) C2H4 than the top-performing catalyst, probably reflecting steric protection at the quaternary CAAC carbon.
- Nascimento, Daniel L.,Gawin, Anna,Gawin, Rafa?,Guńka, Piotr A.,Zachara, Janusz,Skowerski, Krzysztof,Fogg, Deryn E.
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supporting information
p. 10626 - 10631
(2019/08/28)
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- METATHESIS CATALYSTS
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This invention relates generally to olefin metathesis catalysts, to the preparation of such compounds, compositions comprising such compounds, methods of using such compounds, and the use of such compounds in the metathesis of olefins and in the synthesis of related olefin metathesis catalysts. The invention has utility in the fields of catalysis, organic synthesis, polymer chemistry, and in industrial applications such as oil and gas, fine chemicals and pharmaceuticals.
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Paragraph 000118; 000119
(2018/03/09)
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- Selective Hydrogenations and Dechlorinations in Water Mediated by Anionic Surfactant-Stabilized Pd Nanoparticles
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We report a facile, inexpensive, and green method for the preparation of Pd nanoparticles in aqueous medium stabilized by anionic sulfonated surfactants sodium 1-dodecanesulfonate 1a, sodium dodecylbenzenesulfonate 1b, dioctyl sulfosuccinate sodium salt 1c, and poly(ethylene glycol) 4-nonylphenyl-3-sulfopropyl ether potassium salt 1d simply obtained by stirring aqueous solutions of Pd(OAc)2 with the commercial anionic surfactants further treated under hydrogen atmosphere for variable amounts of time. The aqueous Pd nanoparticle solutions were tested in the selective hydrogenation reactions of aryl-alcohols, -aldehydes, and -ketones, leading to complete conversion to the deoxygenated products even in the absence of strong Br?nsted acids in the reduction of aromatic aldehydes and ketones, in the controlled semihydrogenation of alkynes leading to alkenes, and in the efficient hydrodechlorination of aromatic substrates. In all cases, the micellar media were crucial for stabilizing the metal nanoparticles, dissolving substrates, steering product selectivity, and enabling recycling. What is interesting is also that a benchmark catalyst like Pd/C can often be surpassed in activity and/or selectivity in the reactions tested by simply switching to the appropriate commercially available surfactant, thereby providing an easy to use, flexible, and practical catalytic system capable of efficiently addressing a variety of synthetically significant hydrogenation reactions.
- La Sorella, Giorgio,Sperni, Laura,Canton, Patrizia,Coletti, Lisa,Fabris, Fabrizio,Strukul, Giorgio,Scarso, Alessandro
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supporting information
p. 7438 - 7446
(2018/05/29)
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- Accessing Frustrated Lewis Pair Chemistry through Robust Gold@N-Doped Carbon for Selective Hydrogenation of Alkynes
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Pyrolysis of Au(OAc)3 in the presence of 1,10-phenanthroline over TiO2 furnishes a highly active and selective Au nanoparticle (NP) catalyst embedded in a nitrogen-doped carbon support, Au@N-doped carbon/TiO2 catalyst. Parameters such as pyrolysis temperature, type of support, and nitrogen ligands as well as Au/ligand molar ratios were systematically investigated. Highly selective hydrogenation of numerous structurally diverse alkynes proceeded in moderate to excellent yield under mild conditions. The high selectivity toward the industrially important alkene substrates, functional group tolerance, and the high recyclability makes the catalytic system unique. Both high activity and selectivity are correlated with a frustrated Lewis pairs interface formed by the combination of gold and nitrogen atoms of N-doped carbon that, according to density functional theory calculations, can serve as a basic site to promote the heterolytic activation of H2 under very mild conditions. This "fully heterogeneous" and recyclable gold catalyst makes the selective hydrogenation process environmentally and economically attractive.
- Fiorio, Jhonatan Luiz,Gon?alves, Renato Vitalino,Teixeira-Neto, Erico,Ortu?o, Manuel A.,López, Núria,Rossi, Liane Marcia
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p. 3516 - 3524
(2018/04/14)
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- Stable ruthenium olefin metathesis catalysts bearing symmetrical NHC ligands with primary and secondary: N -alkyl groups
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Four novel stable Hoveyda-Grubbs-type catalysts containing N,N′-dineopentyl- and N,N′-dicyclohexyl-substituted N-heterocyclic carbene (NHC) ligands with syn and anti phenyl groups on the ring backbone were synthesized and fully characterized. The catalytic potential of these complexes was investigated in metathesis reactions of both standard and renewable substrates. Compared to the Hoveyda-Grubbs second generation catalyst (HGII), all of the new catalysts showed high performances in most of the examined metathesis transformations. In particular, N,N′-dicyclohexyl catalysts gave improved results in the challenging ring-closing metathesis (RCM) reaction to form tetrasubstituted olefins, while catalysts with neopentyl N-groups were found to be more active and Z-selective in cross-metathesis (CM) reactions. Modest enantioselectivities in the asymmetric ring-closing metathesis (ARCM) of achiral trienes with different steric hindrance were observed in the presence of catalysts bearing chiral C2-symmetric NHC ligands.
- Ambrosio, Chiara,Paradiso, Veronica,Costabile, Chiara,Bertolasi, Valerio,Caruso, Tonino,Grisi, Fabia
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supporting information
p. 6615 - 6627
(2018/05/23)
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- NOVEL RUTHENIUM COMPLEX, METHOD OF ITS PRODUCTION AND ITS USE IN REACTION OF OLEFINE METATHESIS
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The invention relates to novel ruthenium complexes of formula (9). The invention also relates to the method for preparation of novel metal complexes of formula (9) and their use in olefin metathesis reactions.
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Page/Page column 29-30
(2018/06/22)
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- Accessing Alkyl- and Alkenylcyclopentanes from Cr-Catalyzed Ethylene Oligomerization Using 2-Phosphinophosphinine Ligands
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Desilylation of the 2-phosphinophosphinine 2-PPh2-3-Me-6-SiMe3-PC5H2 with HCl gave 2-PPh2-3-Me-PC5H3, demonstrating the late-stage modification of this bidentate heterocyclic lig
- Newland, Robert J.,Smith, Alana,Smith, David M.,Fey, Natalie,Hanton, Martin J.,Mansell, Stephen M.
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p. 1062 - 1073
(2018/03/30)
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- Normal Alpha Olefin Synthesis Using Metathesis and Dehydroformylation
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The present invention discloses processes for producing normal alpha olefins, such as 1-hexene, 1-octene, and 1-decene, in a multistep synthesis scheme. Generally, a first normal alpha olefin is subjected to an olefin metathesis step to form a linear internal olefin, which is then subjected to an isomerization-hydroformylation step to form a linear aldehyde, which is then subjected to a dehydroformylation step to form a second normal alpha olefin.
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Paragraph 0092; 0097; 0098; 0099; 0104; 0105
(2018/05/24)
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- USE OF RUTHENIUM COMPLEXES IN OLEFIN METATHESIS REACTION
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The invention relates to the use of ruthenium complexes, which are homogeneous catalysts and/or precatalysts of the olefin metathesis reaction, which lead to the production of alkenes containing an internal (non-terminal) double C=C bond.
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Page/Page column 18-19
(2018/05/27)
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- Method for preparing alpha-olefin by cracking normal carbonate
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The invention belongs to the field of organic synthesis, and relates to a novel process for synthesizing normal alpha-olefin, in particular to a synthesis process of basic raw materials for products such as an essence, a spice, a medicine, a dye, grease, and resin. The method comprises the following steps: taking a normal alcohol solution, adding dimethyl carbonate to obtain a mixed solution, carrying out heating and stirring to generate carbonic acid normal ester, and carrying out reduced pressure distillation to obtain normal carbonate, wherein in the mixed solution, the molar ratio of normal alcohol to carbonic acid ester is 1:0.6 to 1:2; and carrying out thermal cracking on the normal carbonate in an acidic solution, collecting volatile components in a thermal cracking product, and carrying out concentration and reduced pressure distillation to obtain the normal alpha-olefin. The method provided by the invention has the advantages of short synthesis route, good reaction selectivity, low cost, high yield, high quality, simple raw material source, no high pressure involved, safe and reliable process, strong operability and low environmental impact, and has great market prospect and economic value.
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Paragraph 0020; 0022; 0026-0028
(2018/07/06)
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- An Engineered Self-Sufficient Biocatalyst Enables Scalable Production of Linear α-Olefins from Carboxylic Acids
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Fusing the decarboxylase OleTJE and the reductase domain of P450BM3 creates a self-sufficient protein, OleT-BM3R, which is able to efficiently catalyze oxidative decarboxylation of carboxylic acids into linear α-olefins (LAOs) under mild aqueous conditions using O2 as the oxidant and NADPH as the electron donor. The compatible electron transfer system installed in the fusion protein not only eliminates the need for auxiliary redox partners, but also results in boosted decarboxylation reactivity and broad substrate scope. Coupled with the phosphite dehydrogenase-based NADPH regeneration system, this enzymatic reaction proceeds with improved product titers of up to 2.51 g L-1 and volumetric productivities of up to 209.2 mg L-1 h-1 at low catalyst loadings (~0.02 mol%). With its stability and scalability, this self-sufficient biocatalyst offers a nature-friendly approach to deliver LAOs.
- Lu, Chen,Shen, Fenglin,Wang, Shuaibo,Wang, Yuyang,Liu, Juan,Bai, Wen-Ju,Wang, Xiqing
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p. 5794 - 5798
(2018/06/01)
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- A durable nanocatalyst of potassium-doped iron-carbide/alumina for significant production of linear alpha olefins via Fischer-Tropsch synthesis
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Improvement of activity, selectivity, and stability of the catalyst used in Fischer-Tropsch synthesis (FTS) to produce targeted hydrocarbon products has been a major challenge. In this work, the potassium-doped iron-carbide/alumina (K-Fe5C2/Al2O3), as a durable nanocatalyst containing small iron-carbide particles (~ 10 nm), was applied to high-temperature Fischer-Tropsch synthesis (HT-FTS) to optimize the production of linear alpha olefins. The catalyst, suitable under high space velocity reaction conditions (14–36 N L gcat?1 h?1) based on the well-dispersed potassium as an efficient base promoter on the active iron-carbide surface, shows very high CO conversion (up to ~90%) with extremely high activity (1.41 mmolCO gFe?1 s?1) and selectivity for C5–C13 linear alpha olefins.
- Park, Ji Chan,Jang, Sanha,Rhim, Geun Bae,Lee, Jin Hee,Choi, Hyunkyoung,Jeong, Heon-Do,Youn, Min Hye,Lee, Dong-Wook,Koo, Kee Young,Kang, Shin Wook,Yang, Jung-Il,Lee, Ho-Tae,Jung, Heon,Kim, Chul Sung,Chun, Dong Hyun
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p. 190 - 198
(2018/08/01)
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- Reevaluation of the Palladium/Carbon-Catalyzed Decarbonylation of Aliphatic Aldehydes
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An improved method for the decarbonylation of aliphatic aldehydes by using a commercially available Pd/C catalyst is described. The reaction conditions are suitable for linear, cyclic, or sterically demanding substrates, as they afford the corresponding alkanes in yields of up to 99%. In addition, this Pd/C-catalyzed method exhibits good functional-group tolerance. A comparison of previously reported methods with the present one showed that the reaction conditions play a crucial role in the outcome of the reaction. The method can also be applied in a two-step reaction sequence for the synthesis of industrially important compounds.
- Ajda?i?, Vladimir,Nikoli?, Andrea,Kerner, Michael,Wipf, Peter,Opsenica, Igor M.
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supporting information
p. 1781 - 1785
(2018/08/12)
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- Tandem Catalysis: Transforming Alcohols to Alkenes by Oxidative Dehydroxymethylation
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We report a Rh-catalyst for accessing olefins from primary alcohols by a C-C bond cleavage that results in dehomologation. This functional group interconversion proceeds by an oxidation-dehydroformylation enabled by N,N-dimethylacrylamide as a sacrificial acceptor of hydrogen gas. Alcohols with diverse functionality and structure undergo oxidative dehydroxymethylation to access the corresponding olefins. Our catalyst protocol enables a two-step semisynthesis of (+)-yohimbenone and dehomologation of feedstock olefins.
- Wu, Xuesong,Cruz, Faben A.,Lu, Alexander,Dong, Vy M.
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supporting information
p. 10126 - 10130
(2018/08/23)
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- Hydrochloric acid tests the Uygur logical sequence impurity a last of the ten Heavenly Stems ether preparation method (by machine translation)
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The invention discloses a hydrochloric acid tests the Uygur logical sequence impurity a last of the ten Heavenly Stems ether preparation method, specific steps are: sodium methoxide methanol solution to adding 1 - bromo decane, 20 - 30 °C reaction, after the reaction, is added into the medium and reagent, filtering, the filtrate is concentrated, to join the extractant in the concentrate and water, stirring of the liquid, the organic layer dried, filtered, concentrated to obtain yellow oil of, rectification under vacuum to get. The invention using 1 - bromo decane with sodium methoxide methanol solution reaction preparation armor last of the ten Heavenly Stems ether crude, is rectified to make qualified impurity control armor last of the ten Heavenly Stems ether. The invention raw materials are easy, low toxicity, non-harsh reaction conditions, overall the synthetic route is simple, low cost, high yield (70% or more), high purity of the product (99.2% above, wherein impurity 1 - decene content is smaller than 0.1%), can be hydrochloric acid tests the Uygur logical sequence quality control to provide qualified reference substance. (by machine translation)
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Paragraph 0039; 0040
(2017/04/11)
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- Ethylene oligomerization in zeolite-grafted Cr(III)-diphosphinoamine catalysts using triisobutylaluminium as cocatalyst: Change from dimerization to trimerization due to confinement effect
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Zeolite-supported Cr(III)-diphosphinoamine (Cr(III)-PNP) catalysts were prepared through grafting PNP on HY and NaY zeolites followed by complexing with CrCl3(THF)3 for ethylene oligomerization. The structure of supported Cr(III)-PNP catalysts was characterized by scanning electron microscopy, X-ray diffraction, nitrogen adsorption and desorption, thermogravimetric analyses and Fourier transform infrared, and the influence of the supported pattern on reactivity for ethylene oligomerization were investigated. The results revealed that the complex of Cr(III)-PNP was grafted on silicon hydroxyls in the pore channel of HY zeolite to decrease pore size but to maintain pore structure. Comparing with homogeneous Cr(III)-PNP producing 1-butene as main product, HY-supported catalyst had higher activity and selectivity toward 1-hexene increased from 4.07% to 73.24% using triisobutylaluminium as cocatalyst. The increase is attributed to confinement effect of the pore channel, which increases the stability of the chromacycloheptane intermediate to 1-hexene. The confinement effect for ethylene oligomerization was revealed in experiment.
- Shao, Huaiqi,Wang, Jingjing,Wang, Ruofei,Song, Liwu,Guo, Xiaoyan,Jiang, Tao
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p. 154 - 160
(2017/07/25)
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- Synthesis, Characterization, and Reactivity of Thermally Stable Anhydrous Quaternary Ammonium Fluorides
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The synthesis and properties of a new class of anhydrous quaternary ammonium fluorides, based on the rigid skeleton azabicyclo[2.2.2]octane, is described. Compounds 2a-d were easily prepared by passing the corresponding ammonium iodides over fluoride-based resin followed by drying their hydrated form at 100 or 140 °C under reduced pressure. The stability (experimental and theoretical study), solubility, reactivity, and characterization by solution and solid-state MAS NMR are discussed.
- Elias, Shlomi,Karton-Lifshin, Naama,Yehezkel, Lea,Ashkenazi, Nissan,Columbus, Ishay,Zafrani, Yossi
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supporting information
p. 3039 - 3042
(2017/06/23)
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- Bis(Cyclic Alkyl Amino Carbene) Ruthenium Complexes: A Versatile, Highly Efficient Tool for Olefin Metathesis
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The state-of-the-art in olefin metathesis is application of N-heterocyclic carbene (NHC)-containing ruthenium alkylidenes for the formation of internal C=C bonds and of cyclic alkyl amino carbene (CAAC)-containing ruthenium benzylidenes in the production of terminal olefins. A straightforward synthesis of bis(CAAC)Ru indenylidene complexes, which are highly effective in the formation of both terminal and internal C=C bonds at loadings as low as 1 ppm, is now reported.
- Gawin, Rafa?,Kozakiewicz, Anna,Guńka, Piotr A.,D?browski, Pawe?,Skowerski, Krzysztof
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supporting information
p. 981 - 986
(2017/01/18)
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- Remarkably Efficient Microwave-Assisted Cross-Metathesis of Lipids under Solvent-Free Conditions
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Catalytic transformation of renewable feedstocks into fine chemicals is in high demands and olefin metathesis is a sophisticated tool for biomass conversion. Nevertheless, the large-scale viability of such processes depends on the conversion efficiency, energy efficiency, catalytic activity, selective conversion into desired products, and environmental footprint of the process. Therefore, conversions of renewables by using simple, swift, and efficient methods are desirable. A microwave-assisted ethenolysis and alkenolysis (using 1,5-hexadiene) of canola oil and methyl esters derived from canola oil (COME) and waste/recycled cooking oil (WOME) was carried out by using ruthenium-based catalytic systems. A systematic study using 1st and 2nd generation Grubbs and Hoveyda–Grubbs catalysts was carried out. Among all ruthenium catalysts, 2nd generation Hoveyda–Grubbs catalyst was found to be highly active in the range of 0.002–0.1 mol % loading. The conversions proved to be rapid providing unprecedented turnover frequencies (TOFs). High TOFs were achieved for ethenolysis of COME (21 450 min?1), direct ethenolysis of canola oil (19 110 min?1), for WOME (15 840 min?1) and for cross-metathesis of 1,5-hexadiene with COME (10 920 min?1). The ethenolysis of commercial methyl oleate was also performed with a TOF of 8000 min?1 under microwave conditions.
- Ullah, Aman,Arshad, Muhammad
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p. 2167 - 2174
(2017/05/26)
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- CATALYTIC ETHENOLYSIS OF OPTIONALLY-FUNCTIONALIZED INTERNAL UNSATURATED OLEFINS
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The invention relates to a process for obtaining alpha-olefins by heterogeneous catalytic ethenolysis of optionally-functionalized unsaturated, in particular mono- unsaturated, olefins. The invention also relates to new supported catalysts that can be used in the process of the invention and to a method for preparing said supported catalysts.
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Page/Page column 56-70
(2017/02/09)
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- GROUP 8 TRANSITION METAL CATALYSTS AND METHOD FOR MAKING SAME AND PROCESS FOR USE OF SAME IN OLEFIN DISPROPORTIONATION REACTIONS
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These catalyst compounds are represented by the formula (I and VI): wherein M is a Group 8 metal; X is an anionic ligand; L is a neutral two-electron donor ligand; A is a monotopic or ditopic chelating ligand. The present invention also relates to an easy applicable catalyst synthesis and the application in different olefin metathesis processes, e.g. Reaction Injection Molding (RIM), rotational molding, vacuum infusion, vacuum forming, process for conversion of fatty acids and fatty acid esters or mixtures thereof, in -olefins, dicarboxylic acids or dicarboxylic esters, etc.
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Page/Page column 57-58
(2017/12/09)
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- Effect of the presence of ionic liquid during the NiMoS bulk preparation in the transformation of decanoic acid
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The impact of the presence and amount of [BMIM][NTf2] ionic liquid during the preparation of bulk NiMoS catalysts was investigated. It was clearly shown that these factors have a strong influence on both the morphology and specific surface area of the obtained NiMoS samples. Most interestingly the catalytic activity for the transformation of decanoic acid increased up to three times when IL was present during synthesis. In the same time, a greater selectivity towards hydrocarbons was observed. On the whole a clear relationship between catalytic activity, selectivity and NiMoS morphology was demonstrated. Consequently, it is possible to modify the morphology of the materials and impact the catalytic properties by changing the synthesis conditions.
- Leyral, Géraldine,Brillouet, Soizic,Rousseau, Julie,Richard, Frédéric,Mamede, Anne Sophie,Courthéoux, Laurence,Pradel, Annie,Ribes, Michel,Brunet, Sylvette
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p. 120 - 132
(2017/01/11)
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