- Practical synthesis of pheromone components of Achaea janata (Noctuidae)
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A practical synthesis of pheromone components of Achaea janata utilising double alkylations on TosMIC as key steps has been achieved.
- Yadav,Kache, Rajashaker,Venkatram Reddy,Chandrasekhar
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- Molybdenum Oxide-Modified Iridium Catalysts for Selective Production of Renewable Oils for Jet and Diesel Fuels and Lubricants
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Supported inverse metal-metal oxide catalysts have received significant research interest owing to their effective hydrodeoxygenation (HDO) activity toward biomass substrates, but the high cost of the reported catalysts poses a challenge for commercialization. We present the synthesis of a series of metal-metal oxide catalysts, Ir-MOx/SiO2 (M = Re, Mo, W, V, or Nb) and M′-MoOx/SiO2 (M = Rh, Ru, Pt, or Pd) and their HDO performance on multifuran (high carbon) substrates to produce renewable jet and diesel fuels and lubricant base oils. A MoOx-modified Ir/SiO2 catalyst with a Mo/Ir ratio of 0.13 (Ir-MoOx/SiO2) exhibits the highest product yield (78-96%) under mild reaction conditions. Controlled experiments using probe substrates reveal that furan ring hydrogenation and C-O hydrogenolysis of saturated and unsaturated furan rings occur in a sequential manner. The carbon atom adjacent to the furan or saturated furan ring of substrates or intermediate compounds undergoes slow C-C bond scission, resulting in a small fraction of lighter alkanes. Catalyst characterization suggests that Ir is reduced to a fully metallic state to dissociate hydrogen for hydrogenation. Intact MoOx, partly covering the Ir metal surface, promotes ring opening, hydrogenolysis of etheric and alcoholic C-O bonds, and hydrogenation of Ca? O bonds. This study highlights the potential of low-cost metal-metal oxide catalysts with low loading of oxophilic metals to enable cost-competitive production of bioproducts and demonstrates applicability of these catalysts on other substrates, including fatty acids, fatty esters, and lipids.
- Liu, Sibao,Zheng, Weiqing,Fu, Jiayi,Alexopoulos, Konstantinos,Saha, Basudeb,Vlachos, Dionisios G.
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p. 7679 - 7689
(2019/08/20)
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- Selective Catalytic Hydrogenolysis of Carbon-Carbon σ Bonds in Primary Aliphatic Alcohols over Supported Metals
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The selective scission of chemical bonds is always of great significance in organic chemistry. The cleavage of strong carbon-carbon σ bonds in the unstrained systems remains challenging. Here, we report the selective hydrogenolysis of carbon-carbon σ bonds in primary aliphatic alcohols catalyzed by supported metals under relatively mild conditions. In the case of 1-hexadecanol hydrogenolysis over Ru/TiO2 as a model reaction system, the selective scission of carbon-carbon bonds over carbon-oxygen bonds is observed, resulting in n-pentadecane as the dominant product with a small quantity of n-hexadecane. Theoretical calculations reveal that the 1-hexadecanol hydrogenolysis on flat Ru (0001) undergoes two parallel pathways: i.e. carbon-carbon bond scission to produce n-pentadecane and carbon-oxygen bond scission to produce n-hexadecane. The removal of adsorbed CO on a flat Ru (0001) surface is a crucial step for the 1-hexadecanol hydrogenolysis. It contributes to the largest energy barrier in n-pentadecane production and also retards the rate for n-hexadecane production by covering the active Ru (0001) surface. The knowledge presented in this work has significance not just for a fundamental understanding of strong carbon-carbon σ bond scission but also for practical biomass conversion to fuels and chemical feedstocks.
- Di, Lu,Yao, Sikai,Li, Mengru,Wu, Guangjun,Dai, Weili,Wang, Guichang,Li, Landong,Guan, Naijia
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p. 7199 - 7207
(2015/12/11)
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- Decarboxylation of fatty acids over Pd supported on mesoporous carbon
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Fatty acid decarboxylation was studied in a semibatch reactor over 1 wt.% Pd/C (Sibunit) using five different fatty acids, C17-C20 and C22, as feeds. The same decarboxylation rates were obtained for pure fatty acids, whereas extensive catalyst poisoning and/or sintering and coking occurred with low purity fatty acids as reactants. One reason for catalyst poisoning using behenic acid (C22) as a feedstock was its high phosphorus content. The decarboxylation rate of fatty acids decreased also with increasing fatty acid to metal ratio.
- Simakova, Irina,Simakova, Olga,M?ki-Arvela, P?ivi,Murzin, Dmitry Yu.
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experimental part
p. 28 - 31
(2010/11/16)
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- Efficient heterogeneous dual catalyst systems for alkane metathesis
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A fully heterogeneous and highly efficient dual catalyst system for alkane metathesis (AM) has been developed. The system is comprised of an alumina-supported iridium pincer catalyst for alkane dehydrogenation/olefin hydrogenation and a second heterogeneous olefin metathesis catalyst. The iridium catalysts bear basic functional groups on the aromatic backbone of the pincer ligand and are strongly adsorbed on Lewis acid sites on alumina. The heterogeneous systems exhibit higher lifetimes and productivities relative to the corresponding homogeneous systems as catalyst/catalyst interactions and bimolecular decomposition reactions are inhibited. Additionally, using a two-pot device, the supported Ir catalysts and metathesis catalysts can be physically separated and run at different temperatures. This system with isolated catalysts shows very high turnover numbers and is selective for the formation of high molecular weight alkanes.
- Huang, Zheng,Rolfe, Eleanor,Carson, Emily C.,Brookhart, Maurice,Goldman, Alan S,El-Khalafy, Sahar H.,Roy MacArthur, Amy H.
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experimental part
p. 125 - 135
(2010/06/20)
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- DEGRADATION OF POLYCYCLIC AROMATIC HYDROCARBONS TO RENDER THEM AVAILABLE FOR BIODEGRADATION
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A method for the degradation of polycyclic aromatic compounds is disclosed that involves dissolving ozone in a bipolar solvent comprising a non-polar solvent in which is of sufficiently non-polar character to solubilized the polycyclic aromatic compounds, and a polar-water-compatible solvent which is fully miscible with the non-polar solvent to form a single phase with the non-polar solvent. The bipolar solvent with dissolved ozone is contacted with the polycyclic aromatic compounds to solubilize the polycyclic aromatic compounds and react the dissolved polycyclic aromatic compounds with the ozone to degrade the dissolved polycyclic aromatic compounds to oxygenated intermediates. The bipolar solvent is then mixed with sufficient water to form separate non-polar and polar phases, the non-polar phase comprising the non-polar solvent and the polar phase comprising the non-polar solvent and the oxygenated intermediates. The polar phase is then diluted and incubated with bacteria to biodegrade the oxygenated intermediates.
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Page/Page column 5-8; 15-16
(2008/12/07)
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- A PROCESS FOR THE PREPARATION OF N-HENEICOSANE
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A process for the preparation of n-heneicosane is disclosed. The process comprises (a) reacting 2,4-alkaneanedione with 1-bromooctadecane in absolute ethanol in the presence of 18-crown-6 as catalyst to produce 2-heneicosanone; and (b) reducing said 2-heneicosanone using hydrazine hydrate and potassium hydroxide in ethylene glycol to obtain n-heneicosane.
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Page/Page column 5-7
(2008/06/13)
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- Semivolatile and volatile compounds in combustion of polyethylene
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The evolution of semivolatile and volatile compounds in the combustion of polyethylene (PE) was studied at different operating conditions in a horizontal quartz reactor. Four combustion runs at 500 and 850°C with two different sample mass/air flow ratios and two pyrolytic runs at the same temperatures were carried out. Thermal behavior of different compounds was analyzed and the data obtained were compared with those of literature. It was observed that α,ω-olefins, α-olefins and n-paraffins were formed from the pyrolytic decomposition at low temperatures. On the other hand, oxygenated compounds such as aldehydes were also formed in the presence of oxygen. High yields were obtained of carbon oxides and light hydrocarbons, too. At high temperatures, the formation of polycyclic aromatic hydrocarbons (PAHs) took place. These compounds are harmful and their presence in the combustion processes is related with the evolution of pyrolytic puffs inside the combustion chamber with a poor mixture of semivolatile compounds evolved with oxygen. Altogether, the yields of more than 200 compounds were determined. The collection of the semivolatile compounds was carried out with XAD-2 adsorbent and were analyzed by GC-MS, whereas volatile compounds and gases were collected in a Tedlar bag and analyzed by GC with thermal conductivity and flame ionization detectors.
- Font, Rafael,Aracil, Ignacio,Fullana, Andrés,Conesa, Juan A.
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p. 615 - 627
(2007/10/03)
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- Addition of organocerium reagents to morpholine amides: synthesis of important pheromone components of Achaea janata.
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Readily preparable morpholine amides hitch in good yields with organocerium reagents to produce ketones. Even in the presence of substrates and reagents with high steric hindrance, the organometallic compounds prepared from dry cerium(III) chloride and organomagnesium or organolithium compounds at -78 degrees C add cleanly to morpholine amides. The low cost of starting materials makes this new scheme of synthesis very interesting for the preparation of biologically important pheromones.
- Badioli, Michele,Ballini, Roberto,Bartolacci, Massimo,Bosica, Giovanna,Torregiani, Elisabetta,Marcantoni, Enrico
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p. 8938 - 8942
(2007/10/03)
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- Semi-volatile and particulate emissions from the combustion of alternative diesel fuels
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Motor vehicle emissions are a major anthropogenic source of air pollution and contribute to the deterioration of urban air quality. In this paper, we report results of a laboratory investigation of particle formation from four different alternative diesel fuels, namely, compressed natural gas (CNG), dimethyl ether (DME), biodiesel, and diesel, under fuelrich conditions in the temperature range of 800-1200°C at pressures of approximately 24 atm. A single pulse shock tube was used to simulate compression ignition (CI) combustion conditions. Gaseous fuels (CNG and DME) were exposed premixed in air while liquid fuels (diesel and biodiesel) were injected using a high-pressure liquid injector. The results of surface analysis using a scanning electron microscope showed that the particles formed from combustion of all four of the above-mentioned fuels had a mean diameter less than 0.1 μm. From results of gravimetric analysis and fuel injection size it was found that under the test conditions described above the relative particulate yields from CNG, DME, biodiesel, and diesel were 0.30%, 0.026%, 0.52%, and 0.51%, respectively. Chemical analysis of particles showed that DME combustion particles had the highest soluble organic fraction (SOF) at 71%, followed by biodiesel (66%), CNG (38%) and diesel (20%). This illustrates that in case of both gaseous and liquid fuels, oxygenated fuels have a higher SOF than non-oxygenated fuels. Motor vehicle emissions are a major anthropogenic source of air pollution and contribute to the deterioration of urban air quality. In this paper, we report results of a laboratory investigation of particle formation from four different alternative diesel fuels, namely, compressed natural gas (CNG), dimethyl ether (DME), biodiesel, and diesel, under fuelrich conditions in the temperature range of 800-1200°C at pressures of approximately 24 atm. A single pulse shock tube was used to simulate compression ignition (CI) combustion conditions. Gaseous fuels (CNG and DME) were exposed premixed in air while liquid fuels (diesel and biodiesel) were injected using a high-pressure liquid injector. The results of surface analysis using a scanning electron microscope showed that the particles formed from combustion of all four of the above-mentioned fuels had a mean diameter less than 0.1 μm. From results of gravimetric analysis and fuel injection size it was found that under the test conditions described above the relative particulate yields from CNG, DME, biodiesel, and diesel were 0.30%, 0.026%, 0.52%, and 0.51%, respectively. Chemical analysis of particles showed that DME combustion particles had the highest soluble organic fraction (SOF) at 71%, followed by biodiesel (66%), CNG (38%) and diesel (20%). This illustrates that in case of both gaseous and liquid fuels, oxygenated fuels have a higher SOF than non-oxygenated fuels.
- Sidhu, Sukh,Graham, John,Striebich, Richard
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p. 681 - 690
(2007/10/03)
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- Bruchins - Mitogenic 3-(hydroxypropanoyl) esters of long chain diols from weevils of the bruchidae
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Mono- and bis 3-(hydroxypropanoyl) esters of long chain, unsaturated diols have been isolated and identified from two genera of the family Bruchidae, and have been shown to be responsible for the mitogenic activity observed on pea pods resulting from oviposition by the pea weevil, Bruchus pisorum. The mitogenic compounds have been characterized and synthesized.
- Oliver, James E,Doss, Robert P,Williamson, R.Thomas,Carney, John R,DeVilbiss, E.David
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p. 7633 - 7641
(2007/10/03)
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- Composition and process for augmenting, enhancing or imparting a leather aroma to consumable materials
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Described is the process for augmenting, enhancing or imparting leather aromas to consumable materials including perfume compositions, colognes, perfumed polymers and perfumed articles including solid or liquid anionic, cationic, nonionic or zwitterionic detergents, fabric softener compositions, fabric softener articles, hair preparations, cosmetic powders and the like, by adding thereto a composition of matter consisting of the following ingredients: "A": At least one substance having the structure: STR1 in an amount of from about 1% up to about 5% wherein R9 represents C9 -C11 straight-chain alkyl and wherein R10 represents methyl and X is a moiety selected from the group consisting of: STR2 "B": At least one compound having the structure: STR3 in an amount of from about 3 up to about 7% wherein each of R12 -R15 represents hydrogen or C1 -C4 alkyl with the proviso that at least two of R12 -R15 represents hydrogen; "C": At least one compound having the structure: STR4 in an amount of from about 2% up to about 6% wherein R1, R2, R3, R4 and R5 each represents hydrogen or C1 -C4 alkyl with the proviso that one, two or three of R1, R2, R3, R4 and R5 represents C1 -C4 alkyl; "D": Optionally, at least one compound having the structure: STR5 in an amount of from 0% up to about 1.2% wherein R6 represents hydrogen or methyl and R11 represents hydrogen or methyl with the proviso that at least one of R6 or R11 is hydrogen; "E": At least one compound defined according to the structure: STR6 in an amount of from about 30% up to about 70% wherein R7 represents C11, C13, or C15 straight-chain alkyl and R8 represents C1 -C3 lower alkyl; "F": At least one compound having the structure: STR7 in an amount of from about 20% up to about 60% wherein n represents an integer of from 8 up to 28; "G": Optionally, the compound having the structure: STR8 in an amount of from 0 up to about 6%; and "H": Optionally, the compound having the structure: STR9 in an amount of from 0 up to about 6% with the requirement that: STR10 equal 100%.
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- DISSOLVING METAL REDUCTION WITH CROWN ETHER----- REDUCTIVE DECYANATION
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Toluene radical anion generated from potassium metal/dicyclohexano-18-crown-6/toluene system has been proved to be highly effective for reductive decyanation reaction of primary, secondary and tertiary cyanides.
- Ohsawa, Tomihiko,Kobayashi, Takao,Mizuguchi, Yuko
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p. 6103 - 6106
(2007/10/02)
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