- Selective Hydrodeoxygenation of Vegetable Oils and Waste Cooking Oils to Green Diesel Using a Silica-Supported Ir–ReOx Bimetallic Catalyst
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High yields of diesel-range alkanes are prepared by hydrodeoxygenation of vegetable oils and waste cooking oils over ReOx-modified Ir/SiO2 catalysts under mild reaction conditions. The catalyst containing a Re/Ir molar ratio of 3 exhibits the best performance, achieving 79–85 wt % yield of diesel-range alkanes at 453 K and 2 MPa H2. The yield is nearly quantitative for the theoretical possible long-chain alkanes on the basis of weight of the converted oils. The catalyst retains comparable activity upon regeneration through calcination. Control experiments using probe molecules as model substrates suggest that C=C bonds of unsaturated triglycerides and free fatty acids are first hydrogenated to their corresponding saturated intermediates, which are then converted to aldehyde intermediates through hydrogenolysis of acyl C?O bonds and subsequently hydrogenated to fatty alcohols. Finally, long-chain alkanes without any carbon loss are formed by direct hydrogenolysis of the fatty alcohols. Small amounts of alkanes with one carbon fewer are also formed by decarbonylation of the aldehyde intermediates. A synergy between Ir and partially reduced ReOx sites is discussed to elucidate the high activity of Ir–ReOx/SiO2.
- Liu, Sibao,Simonetti, Trent,Zheng, Weiqing,Saha, Basudeb
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- An unconventional DCOx favored Co/N-C catalyst for efficient conversion of fatty acids and esters to liquid alkanes
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Cobalt (Co) catalysis has recently attracted significant attention in the field of biomass conversion. However, the fabrication of highly dispersive Co nanoparticles at high metal loading with selective facet exposure to achieve specific selectivity is still questionable. In this work, a nitrogen-doped carbon-supported Co catalyst is fabricated for efficient conversion of fatty acids and esters to liquid alkanes. Nitrogen-doping facilitates a highly uniform dispersion of Co nanoparticles even at a high Co loading of 10 wt% and after recycling for 5 runs. The Co/N-C catalyst affords an unconventional decarbonylation/decarboxylation (DCOx) dominant selectivity probably due to partial reduction of cobalt oxides to α-Co0 with only exposure of the (111) facet. Co-existence of Co and N-C leads to strong Lewis acidity and basicity, facilitating the interaction between catalyst and –COOH group, and some important acid-catalyzed step-reactions. The versatility of the Co/N-C catalyst is demonstrated through conversion of various fatty acids and esters.
- Li, Jiang,Liu, Jiaxing,Zhang, Junjie,Wan, Tong,Huang, Lei,Wang, Xintian,Pan, Runze,An, Zhidong,Vlachos, Dionisios G.
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- Permeable composite membrane as a catalytically active contactor for hydrogenation reactions
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The efficiency of using of the permeable composite membrane (PCM) is demonstrated in the 3-phase reaction of liquid substrate with gaseous hydrogen on solid catalyst (PCM acts as a catalytically active contactor) - hydrogenation of fatty acid triglyceride. PCM provides a good combination of the opposite requirements of mild internal diffusion restrictions, low hydraulic resistance, high thermal conductivity, well-developed gas-liquid interface and high catalyst loading in the reactor volume, and thus assures the control of the course of the catalytic reaction.
- Minyukova, T. P.,Shtertser, N. V.,Khassin, A. A.,Yurieva, T. M.
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- Highly Selective Hydrodecarbonylation of Oleic Acid into n-Heptadecane over a Supported Nickel/Zinc Oxide-Alumina Catalyst
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The production of second-generation biodiesel with triglycerides or their derivatives through hydroprocessing is considered as a promising approach to make transportation fuels. In this study, a series of Ni-based catalysts supported on basic composite oxides (MO-Al2O3, M=Mg, Ca, Ni, Cu, Zn) were prepared for the catalytic deoxygenation of oleic acid in the presence of H2. Ni/ZnO-Al2O3 exhibited the highest deoxygenation activity and alkane selectivity, which depended on its moderate basicity. Investigations of the reaction conditions, which include reaction time, reaction temperature, H2 pressure, and Ni loading, suggested that n-heptadecane was the predominant product and its content increased with reaction temperature. The reaction temperature was more important than H2 pressure in the catalytic deoxygenation of oleic acid. Additionally, the overall reaction pathways for the conversion of oleic acid were proposed based on the product distribution for different durations and reaction rates of stearic acid, 1-octadecanol, and stearyl stearate, in which the oxygen atoms in the oleic acid were mainly removed in the form of CO through a hydrogenation-dehydrogenation-decarbonylation reaction route. If glycerol trioleate was used instead of oleic acid, Ni/ZnO-Al2O3 exhibited a high hydrodecarbonylation activity and selectivity to n-heptadecane.
- Li, Guangci,Zhang, Feng,Chen, Lei,Zhang, Chuanhui,Huang, He,Li, Xuebing
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- Influence of the operating conditions and kinetic analysis of the selective hydrogenation of oleic acid on Ru-Sn-B/Al2O3 catalysts
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The influence of the operating conditions on the selectivity and activity of Ru-Sn-B/Al2O3 catalysts for the hydrogenation of oleic acid to oleyl alcohol was studied. It was found that the Ru-Sn-B/Al 2O3 catalyst is selective to oleyl alcohol while Ru or Ru-B/Al2O3 catalysts are not selective to produce oleyl alcohol. The electronic and catalytic properties of Ru are modified by the strong interaction between Sn and B. The incorporation of Sn leads to catalysts capable of producing oleyl alcohol. The experiments of oleic acid hydrogenation showed that an increase in reaction temperature leads to an increase in activity while the selectivity to oleyl alcohol goes through a maximum. This is because the reactions of hydrogenation of CC double bond have lower activation energies than hydrogenolytic reactions. The increase in operating pressure has a positive effect on conversion and a more important effect on selectivity. A very simple first order kinetic model is proposed and reasonably represents the results obtained. This model can be useful to compare catalyst performance more rationally.
- Sánchez, María A.,Pouilloux, Yannick,Mazzieri, Vanina A.,Pieck, Carlos L.
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- Synergistic Interaction between Oxides of Copper and Iron for Production of Fatty Alcohols from Fatty Acids
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The selective hydrogenation of fatty acids to fatty alcohols can be achieved under moderate conditions (180 °C, 30 bar H2) by simultaneously supporting copper and iron oxides on mesoporous silica nanoparticles. The activity of the cosupported oxides is significantly higher than that of each supported metal oxide and of a physical mixture of both individually supported metal oxides. A strong interaction between both metal oxides is evident from dispersion, XRD, TPR, and acetic acid TPD measurements, which is likely responsible for the synergistic behavior of the catalyst. Copper oxide is reduced in situ to its metallic form and thereby activates hydrogen. It is proposed that hydrogen spills over to iron oxide where fatty acids bind and are selectively reduced to the alcohol.
- Kandel, Kapil,Chaudhary, Umesh,Nelson, Nicholas C.,Slowing, Igor I.
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- Kinetics of hydrodeoxygenation of stearic acid using supported nickel catalysts: Effects of supports
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The hydrodeoxygenation of fatty acids derived from vegetable and microalgal oils is a novel process for production of liquid hydrocarbon fuels well-suited with existing internal combustion engines. The hydrodeoxygenation of stearic acid was investigated in a high pressure batch reactor using n-dodecane as solvent over nickel metal catalysts supported on SiO2, γ-Al2O3, and HZSM-5 in the temperature range of 533-563 K. Several supported nickel oxide catalysts with nickel loading up to 25 wt.% were prepared by incipient wetness impregnation method and reduced using hydrogen. The catalysts were then characterized by BET, TPR, H2 pulse chemisorption, TPD, XRD, and ICP-AES. Characterization studies revealed that only dispersed nickel oxide was present up to 15 wt.% nickel loading on γ-Al2O3. The acidity of the supports depends on nickel loading of oxidized catalysts and increases with increasing nickel loading up to 15 wt.%. n-Pentadecane, n-hexadecane, n-heptadecane, n-octadecane, and l-octadecanol were identified as products of hydrodeoxygenation of stearic acid with n-heptadecane being primary product. The catalytic activity and selectivity to products for hydrodeoxygenation of stearic acid depends strongly on acidity of the supports. The maximum selectivity to n-heptadecane was observed with nickel supported γ-Al2O3 catalyst. A suitable reaction mechanism of hydrodeoxygenation of stearic acid was delineated based on products distribution. The conversion of stearic acid was increased with increasing reaction time, nickel loading on γ-Al2O 3, temperature, and catalyst loading. Complete conversion of stearic acid was accomplished with more than 80% selectivity to n-heptadecane at reasonable reaction temperature of 563 K after 240 min of reaction using 15 wt.% Ni/γ-Al2O3 catalyst. An empirical kinetic model was also developed to correlate the experimental data.
- Kumar, Pankaj,Yenumala, Sudhakara Reddy,Maity, Sunil K.,Shee, Debaprasad
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- The selective hydrogenation of ethyl stearate to stearyl alcohol over Cu/Fe bimetallic catalysts
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Bimetallic and monometallic catalysts including Cu and/or Fe species were prepared by a co-precipitation method and their catalytic performance was tested for the selective hydrogenation of ethyl stearate to stearyl alcohol. The bimetallic catalysts were observed to be even more active for this selective hydrogenation compared to the monometallic catalysts and their physical mixtures. With a bimetallic catalyst of Cu/Fe (4/1 in mole ratio) reduced at 200 °C, a selectivity to the alcohol reached to above 99% at a conversion of 97% in reaction for 4 h at 230°C, 3.0 MPa. Effects of composition and reduction temperature on the catalytic performance were studied and the properties of catalysts prepared under different conditions were examined by XRD, TPR, N2 physisorption, and SEM. The relationship of the performance with the properties of the catalysts was discussed, along with the conditions under which synergistic effects of Cu and Fe species appeared and caused the enhancement of the catalytic performance.
- He, Limin,Li, Xiaoru,Lin, Weiwei,Li, Wei,Cheng, Haiyang,Yu, Yancun,Fujita, Shin-Ichiro,Arai, Masahiko,Zhao, Fengyu
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- An efficient hydrogenation catalytic model hosted in a stable hyper-crosslinked porous-organic-polymer: From fatty acid to bio-based alkane diesel synthesis
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In this study, a Pd-based catalytic model over a nitrogen enriched fibrous Porous-Organic-Polymer (POP) is established to execute hydrodeoxygenation of various vegetable oils in producing potential large-scale renewable diesel. Here we report a cost-effective synthesis strategy for a new microporous hypercrosslinked POP through the FeCl3 assisted Friedel-Crafts alkylation reaction, followed by fabrication of Pd0-NPs (2-3 nm) using a solid gas phase hydrogenation route to deliver a novel catalytic system. This catalyst (called Pd@PPN) exhibits versatile catalytic performance for different types of vegetable oils including palm oil, soybean oil, sunflower oil and rapeseed oil to furnish long chain diesel range alkanes. The catalyst is comprehensively characterized using various spectroscopic tools and it shows high stability during five runs of recycling without leaching of Pd. Our results further reveal that a direct decarbonylation (DCN) pathway of fatty acids to produce alkanes with one fewer carbon is the dominant mechanism. Under optimized conditions, using stearic acid to represent the long linear carboxylic acids in the vegetable oils, up to 90% conversion with 83% selectivity of C17-alkane has been achieved on our fabricated catalyst. Density functional theory (DFT) calculations are performed to provide insights into the electronic properties of the catalyst, the mechanistic reaction pathway, the crucial role of the catalyst surface and the product selectivity trend. The strong interaction between the corrugated polymer-frame-structure and the Pd-NPs suggests the presence of high density step sites on the fabricated Pd-NP anchored within the cage of the polymer structure. DFT calculations also reveal the strong promotional effect of step sites and charge transfer in facilitating rate-limiting steps during the decarbonylation (DCN) pathway and removal of strongly bound intermediates formed during the process, therefore explaining the high activity of the fabricated Pd@PPN catayst for the hydrodeoxygenation (HDO) conversion to produce bio-based alkane diesel.
- Sarkar, Chitra,Shit, Subhash Chandra,Dao, Duy Quang,Lee, Jihyeon,Tran, Ngoc Han,Singuru, Ramana,An, Kwangjin,Nguyen, Dang Nam,Le, Quyet Van,Amaniampong, Prince Nana,Drif, Asmaa,Jerome, Francois,Huyen, Pham Thanh,Phan, Thi To Nga,Vo, Dai-Viet N.,Thanh Binh, Nguyen,Trinh, Quang Thang,Sherburne, Matthew P.,Mondal, John
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- Spectroscopy and Reactivity of Dialkoxy Acenes
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Photochemical oxidation of acenes can benefit or impede their function, depending on the application. Although acenes with alkoxy substituents on reactive sites are important for applications as diverse as drug delivery and organic optoelectronics, the influence of chemical structure on their photochemical oxidation remains unknown. This paper therefore describes the synthesis, spectroscopic properties, and reactivity with singlet oxygen (1O2) of a series of dialkoxyacenes that vary in the number and types of fused rings in the (hetero)acene cores. Reductive alkylation of quinone precursors yielded target dialkoxyacenes with fused backbones ranging from benzodithiophene to tetracenothiophene. Trends of their experimental spectroscopic characteristics were consistent with time-dependent density functional theory (TD-DFT) calculations. NMR studies show that photochemically generated 1O2 oxidizes all but one of these acenes to the corresponding endoperoxides in organic solvent. The rates of these oxidations correlate with the number and types of fused arenes, with longer dialkoxyacenes generally oxidizing faster than shorter derivatives. Finally, irradiation of these acenes in acidic, oxidizing environments cleaves the ether bonds. This work impacts those working in organic optoelectronics, as well as those interested in harnessing photogenerated reactive oxygen species in functional materials.
- Brega, Valentina,Kanari, Sare Nur,Doherty, Connor T.,Che, Dante,Sharber, Seth A.,Thomas, Samuel W.
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- Impact of the oxygen defects and the hydrogen concentration on the surface of tetragonal and monoclinic ZrO2 on the reduction rates of stearic acid on Ni/ZrO2
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The role of the specific physicochemical properties of ZrO2 phases on Ni/ZrO2 has been explored with respect to the reduction of stearic acid. Conversion on pure m-ZrO2 is 1.3 times more active than on t-ZrO2, whereas Ni/m-ZrO2 is three times more active than Ni/t-ZrO2. Although the hydrodeoxygenation of stearic acid can be catalyzed solely by Ni, the synergistic interaction between Ni and the ZrO2 support causes the variations in the reaction rates. Adsorption of the carboxylic acid group on an oxygen vacancy of ZrO2 and the abstraction of the a-hydrogen atom with the elimination of the oxygen atom to produce a ketene is the key to enhance the overall rate. The hydrogenated intermediate 1-octadecanol is in turn decarbonylated to heptadecane with identical rates on all catalysts. Decarbonylation of 1-octadecanol is concluded to be limited by the competitive adsorption of reactants and intermediate. The substantially higher adsorption of propionic acid demonstrated by IR spectroscopy and the higher reactivity to O2 exchange reactions with the more active catalyst indicate that the higher concentration of active oxygen defects on m-ZrO2 compared to t-ZrO2 causes the higher activity of Ni/m-ZrO2.
- Foraita, Sebastian,Fulton, John L.,Chase, Zizwe A.,Vjunov, Aleksei,Xu, Pinghong,Barth, Eszter,Camaioni, Donald M.,Zhao, Chen,Lercher, Johannes A.
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- Supported iron nanoparticles for the hydrodeoxygenation of microalgal oil to green diesel
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Iron nanoparticles supported on mesoporous silica nanoparticles (Fe-MSN) catalyze the hydrotreatment of fatty acids with high selectivity for hydrodeoxygenation over decarbonylation and hydrocracking. The catalysis is likely to involve a reverse Mars-Van Krevelen mechanism, in which the surface of iron is partially oxidized by the carboxylic groups of the substrate during the reaction. The strength of the metal-oxygen bonds that are formed affects the residence time of the reactants facilitating the successive conversion of carboxyl first into carbonyl and then into alcohol intermediates, thus dictating the selectivity of the process. The selectivity is also affected by the pretreatment of Fe-MSN, the more reduced the catalyst the higher the yield of hydrodeoxygenation product. Fe-MSN catalyzes the conversion of crude microalgal oil into diesel-range hydrocarbons.
- Kandel, Kapil,Anderegg, James W.,Nelson, Nicholas C.,Chaudhary, Umesh,Slowing, Igor I.
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- In situ hydrogenation and decarboxylation of oleic acid into heptadecane over a Cu-Ni alloy catalyst using methanol as a hydrogen carrier
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In this work, supported Cu-Ni bimetallic catalysts were synthesized and evaluated for the in situ hydrogenation and decarboxylation of oleic acid using methanol as a hydrogen donor. The supported Cu-Ni alloy exhibited a significant improvement in both activity and selectivity towards the production of heptadecane in comparison with monometallic Cu and Ni based catalysts. The formation of the Cu-Ni alloy is demonstrated by high-angle annular dark-field scanning transmission electron microscopy (HADDF-STEM), energy dispersive X-ray spectroscopy (EDS-mapping), X-ray diffraction (XRD) and temperature programmed reduction (TPR). A partially oxidized Cu in the Cu-Ni alloy is revealed by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) following CO adsorption and X-ray photoelectron spectroscopy (XPS). The temperature programmed desorption of ethylene and propane (ethylene/propane-TPD) suggested that the formation of the Cu-Ni alloy inhibited the cracking of C-C bonds compared to Ni, and remarkably increased the selectivity to heptadecane. The temperature programmed desorption of acetic acid (acetic acid-TPD) indicated that the bimetallic Cu-Ni alloy and Ni catalysts had a stronger adsorption of acetic acid than that of the Cu catalyst. The formation of the Cu-Ni alloy and a partially oxidized Cu facilitates the decarboxylation reaction and inhibits the cracking reaction of C-C bonds, leading to enhanced catalytic activity and selectivity.
- Zhang, Zihao,Yang, Qiwei,Chen, Hao,Chen, Kequan,Lu, Xiuyang,Ouyang, Pingkai,Fu, Jie,Chen, Jingguang G.
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- Controlling Hydrodeoxygenation of Stearic Acid to n-Heptadecane and n-Octadecane by Adjusting the Chemical Properties of Ni/SiO2–ZrO2 Catalyst
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A series of SiO2–ZrO2 mixed oxides with varying SiO2 concentrations were hydrothermally synthesized and used as support for Ni in the hydrodeoxygenation of stearic acid. ZrO2 provides a relatively low surface area and only Lewis acid sites, and Ni supported on ZrO2 produces n-heptadecane from stearic acid through hydrogenation and decarbonylation. The SiO2–ZrO2 mixed oxides have a higher specific surface area than ZrO2 as well as an unprecedented spherical and nanolayered morphology. Br?nsted acid sites were created by the incorporation of SiO2 into ZrO2, promoting the hydrodeoxygenation activity of Ni and specifically opening a new reaction route to n-octadecane through the dehydration of 1-octadecanol intermediate into 1-octadecene with subsequent hydrogenation.
- Foraita, Sebastian,Liu, Yue,Haller, Gary L.,Baráth, Eszter,Zhao, Chen,Lercher, Johannes A.
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- New bioactive sulfated metabolites from the Mediterranean tunicate Sidnyum turbinatum
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In addition to the known sodium 3,7,11,15-tetramethylhexadeca-1,19-diyl sulfate (4), the BuOH extract of the Mediterranean tunicate Sidnyum turbinatum was shown to contain four new metabolites: 1-heptadecanyl sulfate (1), 1-octadecanyl sulfate (2), sodium
- Aiello,Carbonelli,Fattorusso,Iuvone,Menna
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- Selective hydrogenation of fatty acids to alcohols over highly dispersed ReOx/TiO2 catalyst the paper is dedicated to the living memory of Dr. Haldor Topsoe.
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Production of fatty alcohols through selective hydrogenation of fatty acids was studied over a 4% ReOx/TiO2 catalyst. Stearic acid was hydrogenated to octadecanol at temperatures and pressures between 180-200°C and 2-4 MPa, with selectivity reaching 93%. A high yield of octadecanol was attributed to a strong adsorption of the acid compared to alcohol on the catalyst, which inhibits further alcohol transformation to alkanes. Low amounts (7%) of alkanes (mainly octadecane) were formed during the conversion of stearic acid. However, it was found that the catalyst could be tuned for the production of alkanes. The reaction intermediates were octadecanal and stearyl stearate. Based on the reaction products analysis and catalyst characterization, a reaction mechanism and possible pathways were proposed.
- Rozmyslowicz, Bartosz,Kirilin, Alexey,Aho, Atte,Manyar, Haresh,Hardacre, Christopher,W?rn?, Johan,Salmi, Tapio,Murzin, Dmitry Yu.
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- Catalytic conversion of Jatropha oil to alkanes under mild conditions with a Ru/La(OH)3 catalyst
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The long-chain alkanes obtained from the hydrodeoxygenation of plant oils are ideal substitutes for diesel. In this work, a new efficient catalytic system was established for the conversion of plant oil to long-chain alkanes under mild conditions with a bi-functional Ru/La(OH)3 catalyst. The hydrodeoxygenation of stearic acid was performed in an autoclave with Ru-based catalysts with different supports (HZSM-5, ZSM-5, SiO2-Al2O3, SiO2, ZrO2, Mg(OH)2, La(OH)3, and La2O3). Among these catalysts, Ru supported on basic La(OH)3 showed a remarkable catalytic performance for the reaction. Over 98% of long-chain alkanes were obtained with 100% conversion of stearic acid at 200 °C and 4 MPa H2. When crude Jatropha oil was hydrogenated, about 80.7 wt% of long chain alkanes were obtained under the optimized conditions (200 °C, 4 MPa H2, 8 h). The high efficiency of the Ru/La(OH)3 catalyst could be due to a co-effect of the high hydrogenation activity of Ru and the basic La(OH)3 support which can attract the acidic raw material. Additionally, the Ru/La(OH)3 catalyst was recycled four times and maintained a good activity and stability. The reaction pathway was also explored by using stearic acid as a model compound. Hydrogenation-decarbonylation could be the main pathway to produce n-heptadecane, which has one carbon atom less than stearic acid.
- Guo, Jian-Hua,Xu, Guang-Yue,Shen, Fei,Fu, Yao,Zhang, Ying,Guo, Qing-Xiang
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- Catalytic production of 1-octadecanol from octadecanoic acid by hydrotreating in a plug flow reactor
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1-Octadecanol (stearic alcohol) has uses ranging from lubricants to perfumes. The production of 1-octadecanol from octadecanoic acid (stearic acid) was investigated in a liquid-phase trickle-bed reactor by hydrogenating octadecanoic acid using a Ni/Co/Mo sulfide catalyst. The primary reactions occurring in the reactor were the desired conversion of octadecanoic acid to 1-octadecanol and the subsequent undesired conversion of 1-octadecanol to octadecane. A model was developed to predict these two reactions. The model found to be most useful for this system was a series-parallel reaction first order in octadecanoic acid and 1-octadecanol and pseudo-zero order in hydrogen for both reactions. The activation energies of the first and second reactions were 63.7.8 and 45.6 kJ/mol, respectively. From these values, the conversion of octadecanoic acid and the selectivity to the desired product as functions of temperature, space velocity, and inlet octadecanoic acid concentration were estimated. The model predicts the maximum productivity of 1-octadecanol occurs at higher temperatures with short residence times. Parametric plots show productivity to be ≥0.48 g 1-octadecanol/g octadecanoic acid at 566 °F and a 0.1 h residence time.
- Potts, Thomas M.,Durant, Keiron,Hestekin, Jamie,Beitle, Robert,Ackerson, Michael
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- Effective conversion of heteroatomic model compounds in microalgae-based bio-oils to hydrocarbons over β-Mo2C/CNTs catalyst
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Hydrotreatment of heteroatomic model compounds in microalgae-based bio-oils into diesel-like hydrocarbons was carried out over carbon nanotubes (CNTs)-supported β-Mo2C catalyst with superior activity and selectivity under a mild condition (≤200 °C). The results show that stearic acid and hexadecanamide can be completely converted into n-C15-C18 alkanes over β-Mo2C/CNTs catalyst. The β-Mo2CC/CNTs favors the pathway of hydrogenation-dehydration-hydrogenation to produce n-octadecane with an optimal yield of 91.24% at a lower temperature of 180 °C during hydrotreating process of stearic acid. The recycle tests demonstrate that the β-Mo2CC/CNTs exhibits excellent stability, and can be reused for seven times consecutively without reduction of catalytic stability. Based on the determined products, a brief reaction pathway is proposed. Therefore, a novel approach to produce diesel-like hydrocarbons via catalytic hydrotreatment of microalgae-based bio-oils over β-Mo2C/CNTs is introduced, which provides a basic research as well as technical parameters for its further industrialization.
- Liang, Junmei,Ding, Ranran,Wu, Yulong,Chen, Yu,Wu, Kejing,Meng, Yongqiang,Yang, Mingde,Wang, Yaowu
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- Hydrodeoxygenation of Palmitic and Stearic Acids on Phosphide Catalysts Obtained In Situ in Reaction Medium
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Abstract: Unsupported phosphide catalysts of composition Ni2P and CoP are prepared in situ in the reaction medium from oil-soluble precursors in the course of hydrodeoxygenation of palmitic and stearic acids. The obtained catalysts are characterized by X-ray powder diffraction and X-ray photoelectron spectroscopy; they show high activity in the hydrodeoxygenation of model substrates. After 6 h of the hydrodeoxygenation reactions, the conversion of palmitic acid reaches 93 and 92% and the conversion of stearic acid is as high as 94 and 91% in the presence of nickel phosphide and cobalt phosphide, respectively. It is shown that the catalyst formed in situ can be isolated and recycled.
- Golubeva,Maksimov
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- Balancing the efficacy vs. the toxicity of promiscuous natural products: Paclitaxel-based acid-labile lipophilic prodrugs as promising chemotherapeutics
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TumorSelect is an anticancer technology that combines cytotoxics, nanotechnology, and knowledge of human physiology to develop innovative therapeutic interventions with minimal undesirable side effects commonly observed in conventional chemotherapy. Tumors have a voracious appetite for cholesterol which facilitates tumor growth and fuels their proliferation. We have transformed this need into a stealth delivery system to disguise and deliver anticancer drugs with the assistance of both the human body and the tumor cell. Several designer prodrugs are incorporated within pseudo-LDL nanoparticles, which carry them to tumor tissues, are taken up, internalized, transformed into active drugs, and inhibit cancer cell proliferation. Highly lipophilic prodrug conjugates of paclitaxel suitable for incorporation into the pseudo-LDL nanoparticles of the TumorSelect delivery vehicle formulation were designed, synthesized, and evaluated in the panel of 24-h NCI-60 human tumor cell line screening to demonstrate the power of such an innovative approach. Taxane prodrugs, viz., ART-207 was synthesized by tethering paclitaxel to lipid moiety with the aid of a racemic solketal as a linker in cost-effective, simple, and straightforward synthetic transformations. In addition to the typical 24-h NCI screening protocol, these compounds were assessed for growth inhibition or killing of ovarian cell lines for 48 and 72h-time intervals and identified the long-lasting effectiveness of these lipophilic prodrugs. All possible, enantiomerically pure isomers of ART-207 were also synthesized, and cytotoxicities were biosimilar to racemic ART-207, suggesting that enantiopurity of linker has a negligible effect on cell proliferation. To substantiate further, ART-207 was evaluated for its in vivo tumor reduction efficacy by studying the xenograft model of ovarian cancer grown in SCID mice. Reduced weight loss (a measure of toxicity) in the ART-207 group was observed, even though it was dosed at 2.5x the paclitaxel equivalent of Abraxane. As a result, our delineated approach is anticipated to improve patient quality of life, patient retention in treatment regimes, post-treatment rapid recovery, and overall patient compliance without compromising the efficacy of the cytotoxic promiscuous natural products.
- Chittiboyina, Amar G.,Claudio, Pier Paolo,Haider, Saqlain,McChesney, James D.,Penfornis, Patrice
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- Redox-active ligand based Mn(i)-catalyst for hydrosilylative ester reduction
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Herein a Mn(i) catalyst bearing a redox-active phenalenyl (PLY) based ligand is reported for the efficient hydrosilylation of esters to alcohols using the inexpensive silane source polymethylhydrosiloxane (PMHS) under mild conditions. Mechanistic investigations suggest a strong ligand-metal cooperation where a ligand-based single electron transfer (SET) process initiates the reaction through Si-H bond activation.
- Chakraborty, Soumi,Das, Arpan,Mandal, Swadhin K.
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supporting information
p. 12671 - 12674
(2021/12/04)
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- MOF-derived hcp-Co nanoparticles encapsulated in ultrathin graphene for carboxylic acids hydrogenation to alcohols
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Highly efficient conversion of carboxylic acids to valuable alcohols is a great challenge for easily corroded non-noble metal catalysts. Here, a series of few-layer graphene encapsulated metastable hexagonal closed-packed (hcp) Co nanoparticles were fabricated by reductive pyrolysis of metal-organic framework precursor. The sample pyrolyzed at 400 °C (hcp-Co@G400) presented outstanding performance and stability for converting a variety of functional carboxylic acids and its turnover frequency was one magnitude higher than that of conventional facc-centered cubic (fcc) Co catalysts. In situ DRIFTS spectroscopy of model reaction acetic acid hydrogenation and DFT calculation results confirm that carboxylic acid initially undergoes dehydroxylation to RCH2CO* followed by consecutive hydrogenation to RCH2CH2OH through RCH2COH*. Acetic acid prefers to vertically adsorb at hcp-Co (0 0 2) facet with a much lower adsorption energy than parallel adsorption at fcc-Co (1 1 1) surface, which plays a key role in decreasing the activation barrier of the rate-determining step of acetic acid dehydroxylation.
- Dong, Mei,Fan, Weibin,Gao, Xiaoqing,Zhu, Shanhui
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p. 201 - 211
(2021/06/03)
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- Selective upgrading of biomass-derived benzylic ketones by (formic acid)–Pd/HPC–NH2 system with high efficiency under ambient conditions
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Upgrading biomass-derived phenolic compounds provides a valuable approach for the production of higher-value-added fuels and chemicals. However, most established catalytic systems display low hydrodeoxygenation (HDO) activities even under harsh reaction conditions. Here, we found that Pd supported on –NH2-modified hierarchically porous carbon (Pd/HPC–NH2) with formic acid (FA) as hydrogen source exhibits unprecedented performance for the selective HDO of benzylic ketones from crude lignin-derived oxygenates. Designed experiments and theoretical calculations reveal that the H+/H? species generated from FA decomposition accelerates nucleophilic attack on carbonyl carbon in benzylic ketones and the formate species formed via the esterification of intermediate alcohol with FA expedites the cleavage of C–O bonds, achieving a TOF of 152.5 h?1 at 30°C for vanillin upgrading, 15 times higher than that in traditional HDO processes (～10 h?1, 100°C–300°C). This work provides an intriguing green route to produce transportation fuels or valuable chemicals from only biomass under mild conditions.
- Chen, Yuzhuo,Chen, Zhirong,Gong, Yutong,Mao, Shanjun,Ning, Honghui,Wang, Yong,Wang, Zhenzhen
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p. 3069 - 3084
(2021/11/16)
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- Enantiomeric synthesis of natural alkylglycerols and their antibacterial and antibiofilm activities
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Alkylglycerols (AKGs) are bioactive natural compounds that vary by alkyl chain length and degree of unsaturation, and their absolute configuration is 2S. Three AKGs (5l–5n) were synthesised in enantiomerically pure form, and were characterised for the first time together with 12 other known and naturally occurring AKGs (5a–5k, 5o). Their structures were established using 1H and 13C APT NMR with 2D-NMR, ESI-MS or HRESI-MS and optical rotation data, and they were tested for their antibacterial and antibiofilm activities. AKGs 5a–5m and 5o showed activity against five clinical isolates and P. aeruginosa ATCC 15442, with MIC values in the range of 15–125 μg/mL. In addition, at half of the MIC, most of the AKGs reduced S. aureus biofilm formation in the range of 23%–99% and P. aeruginosa ATCC 15442 biofilm formation in the range of 14%–64%. The antibiofilm activity of the AKGs assessed in this work had not previously been studied.
- Fernández Montoya, Deicy J.,Contreras Jordan, Luis A.,Moreno-Murillo, Bárbara,Silva-Gómez, Edelberto,Mayorga-Wandurraga, Humberto
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supporting information
p. 2544 - 2550
(2019/11/13)
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- Method for preparing fatty alcohols with same carbon number by catalytic hydrodeoxygenation from fatty acid and/or fatty acid ester
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The invention provides a method for preparing fatty alcohols with the same carbon number by catalytic hydrodeoxygenation from fatty acid and/or fatty acid ester. The method comprises the following step: in a reaction vessel, carrying out hydrodeoxygenation reaction on the fatty acid and/or fatty acid ester and hydrogen in the presence of a catalyst at a low temperature of 100-240 DEG C and under alow hydrogen pressure of 0.1-5 MPa to obtain desired fatty alcohol products with the same carbon number. According to the invention, the fatty alcohols with the same carbon number is prepared from the fatty acid and/or fatty acid ester through an active metal modified MeaXbAlc composite catalyst as defined herein. The method has the advantages of high conversion rate, good selectivity, mild reaction conditions, stable catalyst and the like, and has quite good industrial application prospect.
- -
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Paragraph 0060; 0061; 0062; 0066; 0069; 0078; 0079; 0081
(2019/05/08)
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- Diaminodiphosphine tetradentate ligand and ruthenium complex thereof, and preparation methods and applications of ligand and complex
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The invention discloses a diaminodiphosphine tetradentate ligand and a ruthenium complex thereof, and preparation methods and applications of the ligand and the complex, and provides a ruthenium complex represented by a formula I, wherein L is a diaminodiphosphine tetradentate ligand represented by a formula II, and X and Y are respectively and independently chlorine ion, bromine ion, iodine ion,hydrogen negative ion or BH4. According to the present invention, the ruthenium complex exhibits excellent catalytic activity in the catalytic hydrogenation reactions of ester compounds, has high yield and high chemical selectivity, is compatible with conjugated and non-conjugated carbon-carbon double bond, carbon-carbon triple bond, epoxy, halogen, carbonyl and other functional groups, and hasgreat application prospects.
- -
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Paragraph 0301-0303; 0305
(2019/11/04)
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- Borohydride reduction stabilizing system and method for reducing ester into alcohol
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The invention provides a borohydride reduction stabilizing system and a method for reducing ester into alcohol. The borohydride reduction stabilizing system comprises a borohydride reducing agent anda stabilizer for stabilizing the borohydride reducing agent, wherein the borohydride reducing agent is sodium borohydride or potassium borohydride, and the stabilizer is an alkali metal salt of alcohol. On the basis of an existing sodium borohydride/potassium reducing agent, an alcohol alkali metal salt (such as sodium alcoholate or potassium alcoholate) is added, and then the sodium borohydride/potassium reducing agent can keep stable and is not decomposed under a heating condition, so that on one hand, reduction activity is maintained in a relatively high state and the situation of excessiveuse is reduced, and on the other hand, generation of hydrogen is reduced and the process risk is reduced.
- -
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Paragraph 0140; 0141; 0142; 0143; 0144; 0145
(2019/09/13)
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- Novel clamp metal complex and application thereof
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The invention discloses a method for preparing a novel clamp-shaped complex and application of the novel clamp-shaped complex in the reaction of catalytic hydrogenation of carboxylic acid ester compounds to produce corresponding alcohols and reaction of carbon dioxide catalytic hydrogenation to form formamide compounds. Carboxylic acid esters and hydrogen as raw materials or carbon dioxide, hydrogen and amine compounds as raw materials are reacted in an organic solvent condition or a solvent-free condition in the presence of a transition metal complex as a catalyst to respectively form the corresponding alcohol compounds and/or corresponding formamide compounds. The method has the advantages of being high in reaction efficiency, good in selectivity, mild in conditions, economical, environmentally-friendly, and simple in operation, and has good promotion and application prospects.
- -
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Paragraph 0410-0412; 0442-0445
(2019/04/26)
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- General and Phosphine-Free Cobalt-Catalyzed Hydrogenation of Esters to Alcohols
-
Catalytic hydrogenation of esters is essential for the sustainable production of alcohols in organic synthesis and chemical industry. Herein, we describe the first non-noble metal catalytic system that enables an efficient hydrogenation of non-activated esters to alcohols in the absence of phosphine ligands (with a maximum turnover number of 2391). The general applicability of this protocol was demonstrated by the high-yielding hydrogenation of 39 ester substrates including aromatic/aliphatic esters, lactones, polyesters and various pharmaceutical molecules.
- Shao, Zhihui,Zhong, Rui,Ferraccioli, Raffaella,Li, Yibiao,Liu, Qiang
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supporting information
p. 1125 - 1130
(2019/10/22)
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- Catalytic transfer hydrogenation of oleic acid to octadecanol over magnetic recoverable cobalt catalysts
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Efficient transformation of biomass into fuel and chemicals under mild conditions with cost-effective and environmentally friendly characters is highly desirable but still challenging. Herein, a scalable and Earth-abundant cobalt catalyst was used for selective catalytic transfer hydrogenation (CTH) of unsaturated fatty acids to fatty alcohols with sustainable isopropanol as a hydrogen donor. By tuning the surface Co composition by varying the reduction temperature, the catalytic performance could be easily boosted. At 200 °C in 4 h, the optimal catalyst Co-350 (reduced at 350 °C) gives 100% oleic acid conversion with 91.9% octadecanol selectivity. Various characterization studies reveal that the co-existence of Coδ+ and Co0 over the cobalt core might be responsible for its high performance for CTH of oleic acid. This catalyst could be magnetically separated and is highly stable for reusing ten times. Moreover, this cobalt catalyst is relatively cheap and easy to scale-up, thus achieving a low-cost transformation of biomass into high value-added chemicals.
- Wang, Juncheng,Nie, Renfeng,Xu, Ling,Lyu, Xilei,Lu, Xiuyang
-
supporting information
p. 314 - 320
(2019/01/28)
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- Chemoselective Hydrodeoxygenation of Carboxylic Acids to Hydrocarbons over Nitrogen-Doped Carbon-Alumina Hybrid Supported Iron Catalysts
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The establishment of catalyst systems for the chemoselective hydrodeoxygenation (HDO) of carboxylic acids to hydrocarbons, such as the HDO of long-chain fatty acids to alkanes, is important for biomass to biofuel conversion. As the most abundant and probably the cheapest transition metal on the earth, iron is a promising non-noble-metal alternative to precious metals for large-scale conversion of biomass. However, it usually suffers from unsatisfactory activity. In this work, a nitrogen-doped carbon-alumina hybrid supported iron (Fe-N-C@Al2O3) catalyst is established for chemoselective HDO of carboxylic acids to hydrocarbons. By using stearic acid HDO as the model reaction, n-octadecane and n-heptadecane are produced with yields of 91.9% and 6.0%, respectively. Triglycerides can also be converted into liquid alkanes with a total molar yield of >92%. In addition, the iron catalyst can chemoselectively catalyze the HDO of the carboxylic acid group in the presence of other functional groups such as an aromatic ring. This chemoselectivity has rarely been seen before because the aromatic ring is usually more easily hydrogenated in comparison to HDO of the carboxylic acid group. The characterization results showed that both the formation of a nitrogen-doped carbon-alumina hybrid and the iron loading are important for the Lewis basicity of these catalysts, in order to adsorb the acid substrates. The addition of melamine as the nitrogen precursor during pyrolysis eliminates undesired reactions between the iron precursor and alumina support to form an inactive hercynite phase, leading to the formation of an Fe3C active phase for the hydrogenation of -COOH to -CH2OH and the hybrid of N-C and alumina for the HDO of -CH2OH to -CH3.
- Li, Jiang,Zhang, Junjie,Wang, Shuai,Xu, Guangyue,Wang, Hao,Vlachos, Dionisios G.
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p. 1564 - 1577
(2019/02/03)
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- Biphenyl tridentate ligand ruthenium complex and production method and application thereof
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The invention relates to production methods of a novel biphenyl tridentate ligand and a ruthenium complex of the novel biphenyl tridentate ligand and application of the ruthenium complex of the novelbiphenyl tridentate ligand in reaction of hydrogenation of an ester compound to an alcohol compound. A method for using the biphenyl tridentate ligand ruthenium complex for catalyzing hydrogenation ofthe ester compound to the alcohol compound is characterized by comprising the steps of using the biphenyl tridentate ligand ruthenium complex which is 0.001-0.1 mol% of the amount of substance of theester compound as a catalyst, adding alkali which is 1-10 mol% of the amount of substance of the ester compound, and catalyzing hydrogenation of the ester compound to the corresponding alcohol compound under conditions of 60-100 DEG C and 30-70 MPa hydrogen pressure. The biphenyl tridentate ligand and the ruthenium complex of the biphenyl tridentate ligand are convenient to produce and stable instructure, and the ruthenium complex of the biphenyl tridentate ligand shows excellent catalytic activity in the hydrogenation reaction of the ester compound. The defects of rigorous reaction conditions of high temperature, high pressure and the like needed by existing homogeneous or heterogeneous catalytic system hydrogenated fat compounds and high dosages of catalysts are overcome, the dosage ofthe catalyst is little, the reaction conditions are mild, the selectivity of the reaction is good, and the economical efficiency and the safety of the production system are improved.
- -
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Paragraph 0108-0114
(2019/07/17)
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- Selective Hydroboration of Carboxylic Acids with a Homogeneous Manganese Catalyst
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Catalytic reduction of carboxylic acid to the corresponding alcohol is a challenging task of great importance for the production of a variety of value-added chemicals. Herein, a manganese-catalyzed chemoselective hydroboration of carboxylic acids has been developed with a high turnover number (>99?000) and turnover frequency (>2000 h-1) at 25 °C. This method displayed tolerance of electronically and sterically differentiated substrates with high chemoselectivity. Importantly, aliphatic long-chain fatty acids, including biomass-derived compounds, can efficiently be reduced. Mechanistic studies revealed that the reaction occurs through the formation of active manganese-hydride species via an insertion and bond metathesis type mechanism.
- Barman, Milan K.,Das, Kuhali,Maji, Biplab
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p. 1570 - 1579
(2019/01/30)
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- Mechanistic study of the selective hydrogenation of carboxylic acid derivatives over supported rhenium catalysts
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The structure and performance of TiO2-supported Re (Re/TiO2) catalysts for selective hydrogenation of carboxylic acid derivatives have been investigated. Re/TiO2 promotes selective hydrogenation reactions of carboxylic acids and esters that form the corresponding alcohols, and of amides that generate the corresponding amines. These processes are not accompanied by reduction of aromatic moieties. A Re loading amount of 5 wt% and a catalyst pretreatment with H2 at 500 °C were identified as being optimal to obtain the highest catalytic activity for the hydrogenation processes. The results of studies using various characterization methods, including X-ray diffraction (XRD), X-ray absorption fine structure (XAFS), X-ray photoelectron spectroscopy (XPS), and scanning transmission electron microscopy (STEM), indicate that the Re species responsible for the catalytic hydrogenation processes have sub-nanometer to a few nanometer sizes and average oxidation states higher than 0 and below +4. The presence of either a carboxylic acid and/or its corresponding alcohol is critical for preventing the Re/TiO2 catalyst from promoting production of dearomatized byproducts. Although Re/TiO2 is intrinsically capable of hydrogenating aromatic rings, carboxylic acids, alcohols, amides, and amines strongly adsorb on the Re species, which leads to suppression of this process. Moreover, the developed catalytic system was applied to selective hydrogenation of triglycerides that form the corresponding alcohols.
- Toyao, Takashi,Ting, Kah Wei,Siddiki, S. M. A. Hakim,Touchy, Abeda S.,Onodera, Wataru,Maeno, Zen,Ariga-Miwa, Hiroko,Kanda, Yasuharu,Asakura, Kiyotaka,Shimizu, Ken-ichi
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p. 5413 - 5424
(2019/10/29)
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- Robust cobalt oxide catalysts for controllable hydrogenation of carboxylic acids to alcohols
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The selective catalytic hydrogenation of carboxylic acids is an important process for alcohol production, while efficient heterogeneous catalyst systems are still being explored. Here, we report the selective hydrogenation of carboxylic acids using earth-abundant cobalt oxides through a reaction-controlled catalysis process. The further reaction of the alcohols is completely hindered by the presence of carboxylic acids in the reaction system. The partial reduction of cobalt oxides by hydrogen at designated temperatures can dramatically enhance the catalytic activity of pristine samples. A wide range of carboxylic acids with a variety of functional groups can be converted to the corresponding alcohols at a yield level applicable to large-scale production. Cobalt monoxide was established as the preferred active phase for the selective hydrogenation of carboxylic acids.
- Song, Song,Wang, Dong,Di, Lu,Wang, Chuanming,Dai, Weili,Wu, Guangjun,Guan, Naijia,Li, Landong
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p. 250 - 257
(2018/02/20)
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- Selective Hydrogenation of Carboxylic Acids to Alcohols or Alkanes Employing a Heterogeneous Catalyst
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The chemoselective hydrogenation of carboxylic acids to either alcohols or alkanes is reported, employing a heterogeneous bimetallic catalyst consisting of rhenium and palladium supported on graphite. α-Chiral carboxylic acids were hydrogenated without loss of optical purity. The catalyst displays a reverse order of reactivity upon hydrogenation of different carboxylic functions with esters being less reactive than amides and carboxylic acids. This allows for chemoselective hydrogenation of an acid in the presence of an ester or an amide function.
- Ullrich, Johannes,Breit, Bernhard
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p. 785 - 789
(2018/02/14)
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- Mechanism of supported Ru3Sn7 nanocluster-catalyzed selective hydrogenation of coconut oil to fatty alcohols
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As a promising hydrotreating catalyst, it was previously reported that Ru?OSn (Ru electronically interacts with Sn oxides) on RuSn/SiO2 was the active site for fatty acid hydrogenation, but here in this work we found that Ru3Sn7 nanoclusters on RuSn/SiO2 were responsible for the selective hydrogenation of diverse fatty acids and coconut oil to fatty alcohols. The XPS results indicated no interaction between Snδ+ and Ru0, suggesting that SnOx may exist as isolated species. In contrast, the binding energy shifts of Ru0 and Sn0 in the XPS spectra demonstrated a strong interaction, as a result of the formation of Ru3Sn7 alloy nanoclusters. It was demonstrated that the highest yield of fatty alcohol was obtained with a Sn/Ru ratio of 7/3 (hydrogenation rate: 2.45 g g-1 h-1), and the careful selection of the Sn/Ru ratio and reduction temperatures greatly suppressed the formation of Sn and SnO2 phases. The ratio of the stearyl alcohol formation rate to its consumption rate was 40.8 with Ru3Sn7/SiO2 under the selected conditions. In catalysts with a Sn/Ru ratio higher than 7/3, the presence of additional SnO2 catalyzes the formation of undesired esters at a rate of 0.31 g g-1 h-1. Excess SnO2 would be reduced to Sn at temperatures higher than 600 °C, while Sn can catalyze ester by-product formation at a rate of 0.88 g g-1 h-1. The DFT calculations showed that CH3COOH adsorbs on the Ru3Sn7 (111) surface via Sn-O interactions at the two top sites of adjacent surface Sn atoms, and such adsorption was mainly due to the electrostatic interactions between the molecule and the positively charged surface Sn atoms. The charge density difference (CDD) plots of co-adsorbed CH3CO? and OH? intermediates indicated the bonding relationships between Sn-O and Ru-α-C, suggesting that the surface Sn atoms also took part in the catalytic reaction as an important surface sorption site as well as a Ru3Sn7 structure component, while Ru atoms bonded with α-C and hydrogenated the adsorbed intermediate species with the adsorbed H? to the final alcohol. A further indication that Ru3Sn7 was the active species in the bimetallic Ru-Sn catalyst was given by the much lower energy barrier for hydrogenation of acetic acid in Ru3Sn7 (111) (81.0 kJ mol-1) compared to Ru (0001) (123.5 kJ mol-1).
- Luo, Zhicheng,Bing, Qiming,Kong, Jiechen,Liu, Jing-Yao,Zhao, Chen
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p. 1322 - 1332
(2018/03/13)
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- Construction of bifunctional co/h-zsm-5 catalysts for the hydrodeoxygenation of stearic acid to diesel-range alkanes
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Bifunctional Co/H-ZSM-5 zeolites were prepared by a surface organometallic chemistry grafting route, namely, by the stoichiometric reaction between cobaltocene and the Br?nsted acid sites in zeolites. The catalyst was applied to a model reaction of the catalytic hydrodeoxygenation of stearic acid (SA). The cobalt species existed in the form of isolated Co2 + ions at the exchange positions after grafting, transformed to CoO species on the surface of the zeolite, stabilized inside the zeolite channels upon calcination in air, and finally reduced by hydrogen to homogeneous clusters of metallic cobalt species approximately 1.5 nm in size. During this process, the Br?nsted acid sites of the H-ZSM-5 zeolites were preserved with a slight-ly reduced acid strength. The as-prepared bifunctional catalyst exhibited an approximately 16 times higher activity for the hydrodeoxygenation of SA (2.11 gSA gcat1 h1) than the reference catalyst (0.13 gSA gcat1 h1) prepared by solid-state ion exchange and a high C18 /C17 ratio of approximately 24. The remarkable hydrodeoxygenation performance of the bifunctional Co/H-ZSM-5 was owed to the effective synergy between the uniformed metallic cobalt clusters and the Br?nsted acid sites in H-ZSM-5. The simplified reaction network and kinetics of the SA hydrodeoxygenation catalyzed by the as-prepared bifunctional Co/H-ZSM-5 zeolites were also investigated.
- Wu, Guangjun,Zhang, Nan,Dai, Weili,Guan, Naijia,Li, Landong
-
-
- Direct Synthesis of Polysubstituted Aldehydes via Visible-Light Catalysis
-
Aldehydes are among the most versatile functional groups for synthetic chemistry. However, access to polysubstituted alkyl aldehydes is very limited and requires lengthy synthetic routes that involve multiple-step functional-group conversion. This paper reports a one-step synthesis of polysubstituted aldehydes from readily available olefin substrates using visible-light photoredox catalysis. Despite a number of competing reaction pathways, commercial styrenes react with vinyl ethers selectively in the presence of an acridinium salt photooxidant and a disulfide hydrogen-atom-transfer catalyst under blue LED irradiation. Alkyl aldehydes with different substitution patterns are prepared in good yields. This strategy can be applied to structurally sophisticated substrates.
- Wu, Fengjin,Wang, Leifeng,Chen, Jiean,Nicewicz, David A.,Huang, Yong
-
supporting information
p. 2174 - 2178
(2018/02/06)
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- Selective conversion of coconut oil to fatty alcohols in methanol over a hydrothermally prepared Cu/SiO2 catalyst without extraneous hydrogen
-
A novel one-pot approach selects a hydrothermally synthesized Cu/SiO2 catalyst (consisting of Cu2O·SiO2 and Cu0 surface species) to catalyze the reduction of a series of fatty esters, fatty acids, and coconut oil to fatty alcohols at 240 °C in methanol without extraneous hydrogen, attaining around 85% conversion and 100% selectivity.
- Wu, Liubi,Li, Lulu,Li, Bolong,Zhao, Chen
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p. 6152 - 6155
(2017/07/10)
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- Rhenium-Loaded TiO2: A Highly Versatile and Chemoselective Catalyst for the Hydrogenation of Carboxylic Acid Derivatives and the N-Methylation of Amines Using H2 and CO2
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Herein, we report a heterogeneous TiO2-supported Re catalyst (Re/TiO2) that promotes various selective hydrogenation reactions, which includes the hydrogenation of esters to alcohols, the hydrogenation of amides to amines, and the N-methylation of amines, by using H2 and CO2. Initially, Re/TiO2 was evaluated in the context of the selective hydrogenation of 3-phenylpropionic acid methyl ester to afford 3-phenylpropanol (pH2 =5 MPa, =5 MPa, T=180 °C), which revealed a superior performance over other catalysts that we tested in this study. In contrast to other typical heterogeneous catalysts, hydrogenation reactions with Re/TiO2 did not produce dearomatized byproducts. DFT studies suggested that the high selectivity for the formation of alcohols in favor of the hydrogenation of aromatic rings is ascribed to the higher affinity of Re towards the COOCH3 group than to the benzene ring. Moreover, Re/TiO2 showed a wide substrate scope for the hydrogenation reaction (19 examples). Subsequently, this Re/TiO2 catalyst was applied to the hydrogenation of amides, the N-methylation of amines, and the N-alkylation of amines with carboxylic acids or esters.
- Toyao, Takashi,Siddiki,Morita, Yoshitsugu,Kamachi, Takashi,Touchy, Abeda S.,Onodera, Wataru,Kon, Kenichi,Furukawa, Shinya,Ariga, Hiroko,Asakura, Kiyotaka,Yoshizawa, Kazunari,Shimizu, Ken-Ichi
-
supporting information
p. 14848 - 14859
(2017/10/27)
-
- Mechanistic insights into catalytic carboxylic ester hydrogenation with cooperative Ru(II)-bis{1,2,3-triazolylidene}pyridine pincer complexes
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Transmetallation of newly designed lutidine-based CNC or CNN ligands L, featuring flanking 1,2,3-triazolylidene (tzNHCs) moieties, from Ag(I) to Ru(II) provided access to well-defined cationic [RuII(CO)(H)(L)(PPh3)]+ complexes 2 and 5. Spectroscopic investigations confirm that, in both complexes, the tridentate ligand binds in a rare facial mode to the metal center. The complexes, that exhibit ligand-based reversible deprotonation/dearomatization reactivity, are active in catalytic ester hydrogenation in the presence of KOtBu (≥20 mol%) as an exogenous base. The beneficial effect of the base on catalytic activity relates to transesterification of substrates to the corresponding tert-butyl ester derivatives, which are hydrogenated considerably faster than methyl esters. The mechanistic findings in this work confirm that this transformation is very complex, with this transesterification, metal-ligand cooperative reactivity, base strength and possibly product inhibition all playing a role. Furthermore, relevant Ru(CNC)(hydride) species have been observed by NMR spectroscopy under near-catalytic conditions.
- Sluijter, Soraya N.,Korstanje, Ties J.,van der Vlugt, Jarl Ivar,Elsevier, Cornelis J.
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supporting information
p. 30 - 37
(2017/07/22)
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- SELECTIVE REDUCTION OF ESTERS TO ALCOHOLS
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The present invention relates to a selective reduction of esters to their corresponding alcohols.
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Page/Page column 39
(2017/12/01)
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- Bipyridine ligand ruthenium complex is carried and its preparation method and application (by machine translation)
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The invention relates to a novel bipyridine is carried ligand ruthenium complex and its preparation method and in the ester compound hydrogenation is the application of the alcohol compound in the reaction. The use of the bipyridine ligand ruthenium complex catalytic hydrogenation is carried ester compound alcohol compound method is characterized in that: in order to ester compound material in an amount of 0.001 - 0.3 μM % bipyridyl is carried ligand ruthenium complex as catalyst, adding esters compound material in an amount of 1 - 10mol % alkali, in the 25 - 100 °C and 1 - 10MPa hydrogen pressure catalytic hydrogenation under the conditions of ester compound corresponding alcohol compound. The invention of the bipyridine ligand ruthenium complex is carried is convenient to prepare, stable structure, in the ester compound in hydrogenation reaction exhibits excellent catalytic activity. This invention has overcome the ester compound or a non-homogeneous phase catalytic hydrogenation system requires high-temperature high-pressure reaction conditions and high defects of the catalyst amount, catalyst consumption is small, mild reaction conditions, the reaction selectivity is good, improves the economy and the safety of the production system. (by machine translation)
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-
Paragraph 0098; 0099; 0100; 0101; 0102; 0104
(2017/04/28)
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- TiO2-Supported Re as a General and Chemoselective Heterogeneous Catalyst for Hydrogenation of Carboxylic Acids to Alcohols
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TiO2-supported Re, Re/TiO2, was found to promote selective hydrogenation of carboxylic acids having aromatic and aliphatic moieties to the corresponding alcohols. Re/TiO2showed superior results compared to other transition-metal-loaded TiO2and supported Re catalysts for selective hydrogenation of 3-phenylpropionic acid. 3-phenylpropanol was produced in 97 % yield under mild conditions (5 MPa H2at 140 °C). Contrary to typical heterogeneous catalysts, Re/TiO2does not lead to the formation of dearomatized byproducts. The catalyst is recyclable and shows a wide substrate scope in the synthesis of alcohols (22 examples; up to 97 % isolated yield).
- Toyao, Takashi,Siddiki, S. M. A. Hakim,Touchy, Abeda S.,Onodera, Wataru,Kon, Kenichi,Morita, Yoshitsugu,Kamachi, Takashi,Yoshizawa, Kazunari,Shimizu, Ken-Ichi
-
supporting information
p. 1001 - 1006
(2017/02/05)
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- Long-chain α-ω Diols from renewable fatty acids via tandem olefin metathesis-ester hydrogenation
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Long chain α-ω diols were readily accessed from renewable fatty acid methyl esters following an orthogonal tandem self-metathesis-ester hydrogenation protocol. By adding a base and a bidentate ligand, the metathesis catalysts were transformed in situ into efficient ester hydrogenation catalysts. The selectivity of the hydrogenation reaction was tuned towards the exclusive formation of either the unsaturated or the saturated diol by modifying the ligand/catalyst ratio. An orthogonal tandem cross-metathesis-ester hydrogenation reaction was also applied for the synthesis of a fragrance compound.
- Gonzalez-De-Castro, Angela,Cosimi, Elena,Aguila, Mae Joanne B.,Gajewski, Piotr,Schmitkamp, Mike,De Vries, Johannes G.,Lefort, Laurent
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supporting information
p. 1678 - 1684
(2017/06/07)
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- A mild copper catalyzed method for the selective deprotection of aryl allyl ethers
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Copper boryl reagents enable the selective cleavage of aryl allyl ethers to the corresponding phenols in good to moderate yields.
- Hemming, David S.,Talbot, Eric P.,Steel, Patrick G.
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supporting information
p. 17 - 20
(2016/12/23)
-
- LiCl-mediated, easy, and low-cost removal of the trityl group from protected alcohols and diols: Dedicated to Professor Joaquín Plumet on occasion of his retirement
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The reaction of primary, secondary, phenyl, allyl, and benzyl trityl ethers with lithium chloride in methanol at reflux led to deprotection of the trityl group affording the corresponding alcohol in good to excellent yields under mild reaction conditions.
- Behloul, Cherif,Chouti, Aicha,Chabour, Ihssene,Bey, Hind Bengliz,Guijarro, David,Foubelo, Francisco,Nájera, Carmen,Yus, Miguel
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p. 3526 - 3528
(2016/07/18)
-
- Hydrogenation of dicarboxylic acids to diols over Re-Pd catalysts
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A Re-Pd/SiO2 (Re/Pd = 8) catalyst was applied to hydrogenation of dicarboxylic acids (succinic acid, glutaric acid and adipic acid) to diols. In the hydrogenation of dicarboxylic acids, ex situ liquid-phase (in only 1,4-dioxane solvent) reduced Re-Pd/SiO2 showed much higher activity than in situ liquid-phase (in the mixture of dicarboxylic acid and 1,4-dioxane) and gas-phase reduced ones, in which the in situ liquid-phase reduced catalyst has been reported to show good activity in the hydrogenation of monocarboxylic acids. High diol yields (71-89%) were achieved in the hydrogenation of dicarboxylic acids on the ex situ liquid-phase reduced catalyst at 413 K. Lactones and hydroxycarboxylic acids were first formed as intermediates in the reaction of C4-C5 and ≥C6 dicarboxylic acids, respectively. Characterization using XRD, XPS and XAS indicates that ex situ liquid-phase reduced catalysts with high activity contains comparable amounts of Re0 and Ren+ species, both of which have been reported to be necessary for good performance. The amount of Ren+ species on the in situ liquid-phase reduced catalysts is much larger than that of surface Re0 species. This result suggests that the presence of dicarboxylic acids suppresses the reduction of Re species to Re0 on the calcined catalysts while that of monocarboxylic acids does not, which leads to the low activity in the hydrogenation of dicarboxylic acids on in situ liquid-phase reduced catalysts.
- Takeda, Yasuyuki,Tamura, Masazumi,Nakagawa, Yoshinao,Okumura, Kazu,Tomishige, Keiichi
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p. 5668 - 5683
(2016/07/21)
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- METHOD FOR PRODUCING ALCOHOL BY HYDROGENATION OF CARBOXYLIC ACID COMPOUND, AND RUTHENIUM COMPLEX FOR USE IN THE PRODUCTION METHOD
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PROBLEM TO BE SOLVED: To provide a method of obtaining an alcohol by efficiently hydrogenating a variety of carboxylic acid compounds under mild conditions using a homogeneous catalyst. SOLUTION: The present invention provides a method of hydrogenating a carboxylic acid compound, in the presence of a ruthenium complex represented by RuXnYpZq, in an atmosphere of hydrogen [X is a group represented by the following formula; Y is a phosphine ligand having a substituted/unsubstituted alkyl group or a substituted/unsubstituted aryl group; Z is a ligand other than X and Y; n is 1 or 2; p is an integer of 1-4; q is an integer of 0-2] {R1 is H, a substituted/unsubstituted alkyl group or a substituted/unsubstituted aryl group; A1 and A2 independently represent O, NR4 (R4 is H, a substituted/unsubstituted alkyl group or a substituted/unsubstituted aryl group) or S; m is an integer of 1 or more; a solid line and a dashed line both represent a single bond or a double bond}]. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
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-
Paragraph 0133; 0137; 0138
(2017/02/02)
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- Indium-mediated cleavage of the trityl group from protected alcohols and diols
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The reaction of primary, secondary, allylic and benzylic trityl ethers with indium powder in MeOH/NH4Cl led to reductive cleavage of the trityl-oxygen bond, affording the corresponding alcohols in good to excellent yield under very mild reaction conditions. The detritylation process could successfully be extended to mono and detritylated diols. This methodology represents a new and efficient detritylation procedure under mild reaction conditions.
- Behloul, Cherif,Chouti, Aicha,Guijarro, David,Foubelo, Francisco,Nájera, Carmen,Yus, Miguel
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p. 7937 - 7941
(2016/11/19)
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- METHOD OF PRODUCING ESTOLIDE HAVING HIGH STRUCTURAL STABILITY
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Disclosed is a method of producing an estolide having high structural stability, including: a) preparing a fatty acid mixture from biomass-derived oil; b) separating the fatty acid mixture into a C16 fatty acid and a C18 fatty acid; c) converting the C18 fatty acid into a C18 or C17 linear internal olefin; and d) subjecting the C18 or C17 linear internal olefin and the C16 fatty acid to an estolide reaction, thus obtaining an estolide.
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Paragraph 0092-0093
(2016/05/24)
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- Highly efficient tetradentate ruthenium catalyst for ester reduction: Especially for hydrogenation of fatty acid esters
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A new tetradentate ruthenium complex has been developed for hydrogenation of esters. The catalysts structure features a pyridinemethanamino group and three tight chelating five-membered rings. The structure character is believed to be responsible for its high stability and high carbonylation-resistant properties. Thus, this catalyst shows outstanding performance in the catalytic hydrogenation of a variety of esters, especially for fatty acid esters, which may be used in practical applications. New insight on designing hydrogenation catalyst for reducing esters to alcohols has been provided through theoretical calculations.
- Tan, Xuefeng,Wang, Yan,Liu, Yuanhua,Wang, Fangyuan,Shi, Liyang,Lee, Ka-Ho,Lin, Zhenyang,Lv, Hui,Zhang, Xumu
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supporting information
p. 454 - 457
(2015/03/05)
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- A new designed hydrazine group-containing ruthenium complex used for catalytic hydrogenation of esters
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A hydrazine group-containing nitrogen-phosphine ligand and corresponding ruthenium complexes were synthesized. When these complexes were used for hydrogenation of esters, excellent performance was observed (TON up to 17 200). A wide substrate scope was suitable for this catalytic system.
- Tan, Xuefeng,Wang, Qingli,Liu, Yuanhua,Wang, Fangyuan,Lv, Hui,Zhang, Xumu
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p. 12193 - 12196
(2015/07/27)
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- Hydrogenation of carboxylic acids with a homogeneous cobalt catalyst
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The reduction of esters and carboxylic acids to alcohols is a highly relevant conversion for the pharmaceutical and fine-chemical industries and for biomass conversion. It is commonly performed using stoichiometric reagents, and the catalytic hydrogenation of the acids previously required precious metals. Here we report the homogeneously catalyzed hydrogenation of carboxylic acids to alcohols using earth-abundant cobalt. This system, which pairs Co(BF4)2·6H2O with a tridentate phosphine ligand, can reduce a wide range of esters and carboxylic acids under relatively mild conditions (100°C, 80 bar H2) and reaches turnover numbers of up to 8000.
- Korstanje, Ties J.,Van Der Vlugt, Jarl Ivar,Elsevier, Cornelis J.,De Bruin, Bas
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p. 298 - 302
(2015/10/29)
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- Direct Ruthenium-Catalyzed Hydrogenation of Carboxylic Acids to Alcohols
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The "green" reduction of carboxylic acids to alcohols is a challenging task in organic chemistry. Herein, we describe a general protocol for generation of alcohols by catalytic hydrogenation of carboxylic acids. Key to success is the use of a combination of Ru(acac)3, triphos and Lewis acids. The novel method showed broad substrate tolerance and a variety of aliphatic carboxylic acids including biomass-derived compounds can be smoothly reduced.
- Cui, Xinjiang,Li, Yuehui,Topf, Christoph,Junge, Kathrin,Beller, Matthias
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supporting information
p. 10596 - 10599
(2015/09/02)
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- Design and synthesis of protein kinase C epsilon selective diacylglycerol lactones (DAG-lactones)
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DAG-lactones afford a synthetically accessible, high affinity platform for probing structure activity relationships at the C1 regulatory domain of protein kinase C (PKC). Given the central role of PKC isoforms in cellular signaling, along with their differential biological activities, a critical objective is the design of isoform selective ligands. Here, we report the synthesis of a series of DAG-lactones varying in their side chains, with a particular focus on linoleic acid derivatives. We evaluated their selectivity for PKC epsilon versus PKC alpha both under standard lipid conditions (100% phosphatidylserine, PS) as well as in the presence of a nuclear membrane mimetic lipid mixture (NML). We find that selectivity for PKC epsilon versus PKC alpha tended to be enhanced in the presence of the nuclear membrane mimetic lipid mixture and, for our lead compound, report a selectivity of 32-fold.
- Ann, Jihyae,Yoon, Suyoung,Baek, Jisoo,Kim, Da Hye,Lewin, Nancy E.,Hill, Colin S.,Blumberg, Peter M.,Lee, Jeewoo
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p. 332 - 341
(2015/05/04)
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