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Journal articles on the topic 'Dehydrogenation'

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Author: Grafiati

Published: 4 June 2021

Last updated: 29 July 2024

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1

Maji, Biplab, and Milan Barman. "Recent Developments of Manganese Complexes for Catalytic Hydrogenation and Dehydrogenation Reactions." Synthesis 49, no. 15 (July 13, 2017): 3377–93. http://dx.doi.org/10.1055/s-0036-1590818.

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Being the third most abundant transition metal in the Earth’s crust (after iron and titanium) and less toxic, reactions catalyzed by manganese are becoming very important. A large number of manganese complexes have been synthesized using bidentate and tridentate ligands. Such manganese complexes display excellent catalytic activities for various important organic transformations, such as hydrogenation, dehydrogenation, dehydrogenative coupling, transfer hydrogenation reactions, etc. In this short review, recent developments of such manganese-catalyzed reactions are presented.1 Introduction2 Well-Defined Manganese-Complex-Catalyzed Hydrogenation Reactions2.1 Hydrogenation of Nitriles2.2 Hydrogenation of Aldehydes and Ketones2.3 Hydrogenation of Esters2.4 Hydrogenation of Amides2.5 Hydrogenation of Carbon Dioxide3 Manganese-Catalyzed Dehydrogenation Reactions3.1 Selective Dehydrogenation of Methanol3.2 Dehydrogenative N-Formylation of Amines by Methanol3.3 Dehydrogenative Coupling Reactions of Alcohols3.4 Imine Synthesis via Dehydrogenative Coupling of Alcohols and Amines3.5 Synthesis of N-Heterocycles via Dehydrogenative Coupling4 Manganese-Catalyzed Dehydrogenation–Hydrogenation Cascades4.1 N-Alkylation of Amines with Primary Alcohols4.2 α-Alkylation of Ketones with Primary Alcohols4.3 Transfer Hydrogenation of Ketones5 Conclusion

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2

Luo, Zheng, Huayou Hu, Chao Wang, Zhen Yang, and Yefei Wang. "A domino reaction for the synthesis of pyrrolo[2,1-a]isoquinolines from 2-aryl-pyrrolidines and alkynes promoted by a four-component catalytic system under aerobic conditions." RSC Advances 13, no. 50 (2023): 35617–20. http://dx.doi.org/10.1039/d3ra07653a.

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3

Bossola, Filippo, and Nicola Scotti. "Editorial: Special Issue on “Advances on Catalysts Based on Copper”." Catalysts 13, no. 4 (April 4, 2023): 700. http://dx.doi.org/10.3390/catal13040700.

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Copper-based catalysts are very active in a wide range of different reactions, such as methanol synthesis, steam reforming/WGS, hydrogenation/dehydrogenation/transfer hydrogenation, oxidation, dehydrogenative coupling, acid-base reactions, etc [...]

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4

Zhang, Chang-Wu, Jing Wen, Lei Wang, Xin-Ge Wang, and Lei Shi. "Iron doping boosts the reactivity and stability of the γ-Al2O3 nanosheet supported cobalt catalyst for propane dehydrogenation." New Journal of Chemistry 44, no. 18 (2020): 7450–59. http://dx.doi.org/10.1039/d0nj00381f.

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This study describes a new iron-doping strategy to improve both the reactivity and stability of a cobalt catalyst in propane dehydrogenation, meanwhile, the defective γ-Al₂O₃ nanosheet synergistically boosted the dehydrogenating activity of that.

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5

Teng, Qing-Hu, Yan-Yan Chen, Yan Yao, and Xiu-Jin Meng. "Electrochemical Synthesis of Quinazolinones by the Metal-Free and Acceptor-Free Dehydrogenation of 2-Aminobenzamides." Synlett 31, no. 18 (August 19, 2020): 1795–99. http://dx.doi.org/10.1055/s-0040-1707248.

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An efficient approach has been developed for the construction of quinazolin-4(3H)-ones by the selective anodic dehydrogenative oxidation/cyclization of benzylic chlorides and 2-aminobenzamides. The method features acceptor-free and metal-free dehydrogenation of amines to imines; a subsequent intermolecular addition provides the products in moderate to good yields.

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6

Wang, Wan-Qiang, Hua Cheng, Ye Yuan, Yu-Qing He, Hua-Jing Wang, Zhi-Qin Wang, Wei Sang, Cheng Chen, and Francis Verpoort. "Highly Efficient N-Heterocyclic Carbene/Ruthenium Catalytic Systems for the Acceptorless Dehydrogenation of Alcohols to Carboxylic Acids: Effects of Ancillary and Additional Ligands." Catalysts 10, no. 1 (December 19, 2019): 10. http://dx.doi.org/10.3390/catal10010010.

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The transition-metal-catalyzed alcohol dehydrogenation to carboxylic acids has been identified as an atom-economical and attractive process. Among various catalytic systems, Ru-based systems have been the most accessed and investigated ones. With our growing interest in the discovery of new Ru catalysts comprising N-heterocyclic carbene (NHC) ligands for the dehydrogenative reactions of alcohols, we designed and prepared five NHC/Ru complexes ([Ru]-1–[Ru]-5) bearing different ancillary NHC ligands. Moreover, the effects of ancillary and additional ligands on the alcohol dehydrogenation with KOH were thoroughly explored, followed by the screening of other parameters. Accordingly, a highly active catalytic system, which is composed of [Ru]-5 combined with an additional NHC precursor L5, was discovered, affording a variety of acid products in a highly efficient manner. Gratifyingly, an extremely low Ru loading (125 ppm) and the maximum TOF value until now (4800) were obtained.

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7

Guo, Jia Neng, Jin Zhi Lin, Xin Liu, Qi Wei Wang, Ge Gao, Xiang Zhang, Xin Ge Shi, Bei Yang, and Hai Bo Jin. "The Progress of Catalyst for Cyclohexane Dehydrogenation Processes." Advanced Materials Research 953-954 (June 2014): 1261–68. http://dx.doi.org/10.4028/www.scientific.net/amr.953-954.1261.

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Cyclohexane dehydrogenation is an important process in the petrochemical industry, chemical raw material such as cyclohexanol, cyclohexanone,benzene and cyclohexene can be produced from which.Divided cyclohexane dehydrogenation into catalytic dehydrogenation or oxidative dehydrogenation, homogeneous or heterogeneous reaction. Summarized vary catalysts, active constituent and process conditions in dehydrogenation process.

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8

Möhrle, H., and M. Jeandrée. "1,3-Dioxolane von N-substituierten 4-Piperidonen als Dehydrierungssubstrat / 1,3-Dioxolanes of N-Substituted 4-Piperidones as Substrates for Dehydrogenations." Zeitschrift für Naturforschung B 52, no. 1 (January 1, 1997): 72–78. http://dx.doi.org/10.1515/znb-1997-0115.

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The applicability of ketals was examined for masking the carbonyl group in N-tertiary 4-piperidones during the dehydrogenation using mercury-edta. Various 1,3-dioxolanes showed a different behaviour in dependence on the N-substituent. With simple aliphatic moieties mainly dehydrogenated but hydrolyzed products were received. These enaminones were also available from the dehydrogenations of the corresponding 4-piperidones. Similar applied to para-acyl-aromatic substituted derivatives but with less yields. Aromatic substituents bearing a neighbour group on ortho-position with participation gave rise to different oxidation products partially with preservation of the ketal structure

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9

Zhang, Yanghuan, Meng Ji, Zeming Yuan, Wengang Bu, Yan Qi, and Shihai Guo. "Catalytic effect of MoS2 on hydrogen storage thermodynamics and kinetics of an as-milled YMg11Ni alloy." RSC Advances 7, no. 60 (2017): 37689–98. http://dx.doi.org/10.1039/c7ra05965e.

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10

Yuan, Zeming, Wei Zhang, Peilong Zhang, Yanghuan Zhang, Wengang Bu, Shihai Guo, and Dongliang Zhao. "Improvement in the hydrogen storage performance of the as-milled Sm–Mg alloys using MoS2 nano-particle catalysts." RSC Advances 7, no. 89 (2017): 56365–74. http://dx.doi.org/10.1039/c7ra10160k.

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11

Li, Tong, Kun Wang, and Jian-Guo Zhang. "Theoretical study of the structure and dehydrogenation mechanism of sodium hydrazinidoborane." Journal of Theoretical and Computational Chemistry 16, no. 03 (March 2, 2017): 1750020. http://dx.doi.org/10.1142/s0219633617500201.

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Alkali-metal hydrazinidoboranes have been recently investigated as a new stable high-capacity material for hydrogen storage, necessitating an exploration of the dehydrogenation mechanism for further developments in this field. Herein, we present a first systematic study of the structure and dehydrogenation mechanism of sodium hydrazinidoborane (NaHB) with three possible pathways considered: pathway A, corresponding to unimolecular dehydrogenation; pathway B, featuring dehydrogenation of the (NaHB)2 dimer via two different sub-pathways, and pathway C, corresponding to direct dehydrogenation (as compared to B). The calculated rate of the most probable dehydrogenation pathway (B, 3.28[Formula: see text]min[Formula: see text] is similar to that obtained experimentally (12.26[Formula: see text]min[Formula: see text], supporting the validity of our findings.

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12

Li, Xiuyi, and Chunyi Li. "Effect of Residence Time and Carrier Gas on the Dehydrogenation of n-Hexane over Alumina-supported Chromium Catalyst." Advances in Engineering Technology Research 9, no. 1 (January 18, 2024): 377. http://dx.doi.org/10.56028/aetr.9.1.377.2024.

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CrOx/γ-Al2O3 catalyst was prepared by incipient wetness impregnation method, and the influence of residence time and carrier gas on the dehydrogenation of n-hexane were studied. It is found that n-hexane dehydrogenation over CrOx/γ-Al2O3 catalyst with H2 as carrier gas exhibits totally different catalytic behaviors with that of diluting n-hexane with N2. When diluting feed with N2, the selectivity to dehydrogenation product is promoted while the cracking reaction is exhibited with reducing residence time. However, the selectivity to dehydrogenation product is significantly decreased while the isomerization of n-hexane is promoted when using H2 as carrier gas. It is proposed that H2 undergoes dissociation on the dehydrogenation active site, and further facilitates the olefinic dehydrogenation products to form carbocation, which performing isomerization reaction on the acid site on the γ-Al2O3 surface. Therefore, the isomerization of n-hexane is promoted in cost of the selectivity to dehydrogenation product when using H2 as carrier gas.

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13

Karimov, Eduard Kh, Oleg Kh Karimov, Liliya Z. Kasyanova, Eldar M. Movsumzade, and Yuri K. Dmitriev. "Dehydrogenation of Methylbutenes with Intermediate Oxidation of Hydrogen." Key Engineering Materials 685 (February 2016): 764–67. http://dx.doi.org/10.4028/www.scientific.net/kem.685.764.

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In the paper we study a method of increasing the yield of dehydrogenation products of methylbutenes by virtue of intermediate removal of the hydrogen formed during the dehydrogenation and partial compensation of heat losses. In the example of dehydrogenation of methylbutenes into the isoprene, the oxidation of hydrogen on the platinum catalyst [charged inside the layer of ferric potassium catalyst] for the dehydrogenation of olefins is considered.

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14

Yang, Xinchun, Dmitri A. Bulushev, Jun Yang, and Quan Zhang. "New Liquid Chemical Hydrogen Storage Technology." Energies 15, no. 17 (August 31, 2022): 6360. http://dx.doi.org/10.3390/en15176360.

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The liquid chemical hydrogen storage technology has great potentials for high-density hydrogen storage and transportation at ambient temperature and pressure. However, its commercial applications highly rely on the high-performance heterogeneous dehydrogenation catalysts, owing to the dehydrogenation difficulty of chemical hydrogen storage materials. In recent years, the chemists and materials scientists found that the supported metal nanoparticles (MNPs) can exhibit high catalytic activity, selectivity, and stability for the dehydrogenation of chemical hydrogen storage materials, which will clear the way for the commercial application of liquid chemical hydrogen storage technology. This review has summarized the recent important research progress in the MNP-catalyzed liquid chemical hydrogen storage technology, including formic acid dehydrogenation, hydrazine hydrate dehydrogenation and ammonia borane dehydrogenation, discussed the urgent challenges in the key field, and pointed out the future research trends.

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15

Bonitatibus, Peter J., Sumit Chakraborty, Mark D. Doherty, Oltea Siclovan, William D. Jones, and Grigorii L. Soloveichik. "Reversible catalytic dehydrogenation of alcohols for energy storage." Proceedings of the National Academy of Sciences 112, no. 6 (January 14, 2015): 1687–92. http://dx.doi.org/10.1073/pnas.1420199112.

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Reversibility of a dehydrogenation/hydrogenation catalytic reaction has been an elusive target for homogeneous catalysis. In this report, reversible acceptorless dehydrogenation of secondary alcohols and diols on iron pincer complexes and reversible oxidative dehydrogenation of primary alcohols/reduction of aldehydes with separate transfer of protons and electrons on iridium complexes are shown. This reactivity suggests a strategy for the development of reversible fuel cell electrocatalysts for partial oxidation (dehydrogenation) of hydroxyl-containing fuels.

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16

Rioux, R. M., and M. A. Vannice. "Hydrogenation/dehydrogenation reactions: isopropanol dehydrogenation over copper catalysts." Journal of Catalysis 216, no. 1-2 (May 2003): 362–76. http://dx.doi.org/10.1016/s0021-9517(02)00035-0.

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17

Xie, Lin-Jie, Jun-Cheng Jiang, An-Chi Huang, Yan Tang, Ye-Cheng Liu, Hai-Lin Zhou, and Zhi-Xiang Xing. "Calorimetric Evaluation of Thermal Stability of Organic Liquid Hydrogen Storage Materials and Metal Oxide Additives." Energies 15, no. 6 (March 18, 2022): 2236. http://dx.doi.org/10.3390/en15062236.

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The effects of two different metal oxide catalysts, SnO and Li2O, on the dehydrogenation temperature of Carbazole and N-Ethylcarbazole (NE), respectively, were investigated by the Thermogravimetric analyzer and Differential Scanning Calorimetry. Thermogravimetric experiments were performed with 10wt% SnO and Li2O added to Carbazole and N-Ethylcarbazole, respectively, and compared to pure Carbazole and N-Ethylcarbazole. The results showed that the dehydrogenation temperature of N-Ethylcarbazole was lower than that of Carbazole, and the dehydrogenation temperature of N-Ethylcarbazole +SnO was the lowest, and SnO is an ideal dehydrogenation catalyst for N-Ethylcarbazole. Experiments using Differential Scanning Calorimetry and a Thermogravimetric analyzer showed that with the addition of catalyst, the activation energy of the mixture was more significant and stable, and the thermal hazard was reduced, whereas the relative dehydrogenation temperature was increased. This study provides important information for improving the design of dehydrogenation catalysts for organic liquid hydrogen storage processes.

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18

Zuo, Cheng, and Qian Su. "Research Progress on Propylene Preparation by Propane Dehydrogenation." Molecules 28, no. 8 (April 20, 2023): 3594. http://dx.doi.org/10.3390/molecules28083594.

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At present, the production of propylene falls short of the demand, and, as the global economy grows, the demand for propylene is anticipated to increase even further. As such, there is an urgent requirement to identify a novel method for producing propylene that is both practical and reliable. The primary approaches for preparing propylene are anaerobic and oxidative dehydrogenation, both of which present issues that are challenging to overcome. In contrast, chemical looping oxidative dehydrogenation circumvents the limitations of the aforementioned methods, and the performance of the oxygen carrier cycle in this method is superior and meets the criteria for industrialization. Consequently, there is considerable potential for the development of propylene production by means of chemical looping oxidative dehydrogenation. This paper provides a review of the catalysts and oxygen carriers employed in anaerobic dehydrogenation, oxidative dehydrogenation, and chemical looping oxidative dehydrogenation. Additionally, it outlines current directions and future opportunities for the advancement of oxygen carriers.

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19

Aliyev, A. M., G. A. Ali-zade, M. Q. Aliyeva, A. R. Safarov, V. M. Yariyev, and R. A. Ahmedov. "RESEARCH INTO REACTION ABILITY OF CYCLOHEXANOL AND METHYLCYCLOHEXANOLS IN THE OXIDATIVE DEHYDRATION REACTION OVER MODIFIED ZEOLITE CATALYSTS." Chemical Problems 19, no. 2 (2021): 101–6. http://dx.doi.org/10.32737/2221-8688-2021-2-101-106.

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The article studied and compared the reactivity of cyclohexanol and methylcyclohexanol isomers in the oxidative dehydrogenation reaction over modified zeolite catalysts. It found that rates of oxidative dehydrogenation of all methylcyclohexanol isomers are practically the same and exceed rates of oxidative dehydrogenation of cyclohexanol into cyclohexanone.

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20

He, Qing, Dongdong Zhu, Xiaocheng Wu, Duo Dong, Meng Xu, and Zhaofei Tong. "Hydrogen Desorption Properties of LiBH4/xLiAlH4 (x = 0.5, 1, 2) Composites." Molecules 24, no. 10 (May 15, 2019): 1861. http://dx.doi.org/10.3390/molecules24101861.

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A detailed analysis of the dehydrogenation mechanism of LiBH4/xLiAlH4 (x = 0.5, 1, 2) composites was performed by thermogravimetry (TG), differential scanning calorimetry (DSC), mass spectral analysis (MS), powder X-ray diffraction (XRD) and scanning electronic microscopy (SEM), along with kinetic investigations using a Sievert-type apparatus. The results show that the dehydrogenation pathway of LiBH4/xLiAlH4 had a four-step character. The experimental dehydrogenation amount did not reach the theoretical expectations, because the products such as AlB2 and LiAl formed a passivation layer on the surface of Al and the dehydrogenation reactions associated with Al could not be sufficiently carried out. Kinetic investigations discovered a nonlinear relationship between the activation energy (Ea) of dehydrogenation reactions associated with Al and the ratio x, indicating that the Ea was determined both by the concentration of Al produced by the decomposition of LiAlH4 and the amount of free surface of it. Therefore, the amount of effective contact surface of Al is the rate-determining factor for the overall dehydrogenation of the LiBH4/xLiAlH4 composites.

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21

Wang, Haiou, Qiusheng Yang, Yucong Song, and Yanji Wang. "Thermodynamic Analysis and Experimental Study of Selective Dehydrogenation of 1,2-cyclohexanediol over Cu2+1O/MgO Catalysts." Sustainability 11, no. 3 (February 10, 2019): 902. http://dx.doi.org/10.3390/su11030902.

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The dehydrogenation of 1,2-cyclohexanediol (CHD) helps in the effective utilization of not only fossil derivatives but also vicinal diols and polyols from sustainable biomass-derived resources. A thermodynamic analysis of CHD dehydrogenation was computed with density functional theory (DFT) calculation using Gaussian 09. The result indicates that CHD can be converted to 2-hydroxy cyclohexanone (HCO), 2-hydroxy-2-cyclohexen-1-one (HCEO) and pyrocatechol depending on the degree of dehydrogenation. HCO and HCEO are the stable products of the primary and secondary dehydrogenation. Experimentally, Cu/MgO catalysts were prepared using glucose as a reductant, and were characterized by SEM, TEM, XRD, XPS, TPR, BET and ICP. Furthermore, their catalytic performance regarding the oxygen-free dehydrogenation of CHD was investigated. The results indicate that the primary active crystalline phase of Cu/MgO was Cu2+1O, and that the dehydrogenation products were mainly HCO and HCEO, in accordance with thermodynamic predictions. Upon optimizing the reaction conditions, the total selectivity of HCO and HCEO exceeded 90% and the conversion of CHD was approximately 95%.

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22

Morales-Morales, David, Rocío Redón, Zhaohui Wang, Do W. Lee, Cathleen Yung, Kevin Magnuson, and Craig M. Jensen. "Selective dehydrogenation of alcohols and diols catalyzed by a dihydrido iridium PCP pincer complex." Canadian Journal of Chemistry 79, no. 5-6 (May 1, 2001): 823–29. http://dx.doi.org/10.1139/v01-070.

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The PCP pincer complex, IrH2{C6H3-2,6-(CH2P-t-Bu2)2} (1) catalyzes the transfer dehydrogenation of primary and secondary alcohols. Dehydrogenation occurs across the CO bond rather than the CC bonds and the corresponding aldehydes or ketones are obtained as the sole products arising from the dehydrogenation reactions. Methanol is an exception to this pattern of reactivity and undergoes only stoichiometric dehydrogenation with 1 to give the carbonyl complex, Ir(CO){C6H3-2,6-(CH2P-t-Bu2)2} (2). The products are obtained in nearly quantitative yields when the reactions are carried out in toluene solutions. Under the same conditions, 2,5-hexanediol is converted to the annulated product, 3-methyl-2-cyclopenten-1-one which has been isolated in 91% yield in a preparative scale reaction.Key words: alcohol, dehydrogenation, ketones, iridium pincer complex, annulation.

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23

Belomestnykh, I. P., N. N. Rozhdestvenskaya, and G. V. Isogulyants. "Oxidative dehydrogenation of alkylheteroaromatic compounds. 2*. Dehydrogenation of alkylthiophenes." Chemistry of Heterocyclic Compounds 30, no. 8 (August 1994): 888–91. http://dx.doi.org/10.1007/bf01165024.

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24

Echevsky, G. V. "Bifunctional Zeolite- and Aluminophosphate-Based Catalysts for Hydrocracking and Hydroisodeparaffinization. Part 1. The Influence of the Nature and Activity of the Hydrogenating and Acidic Components on the Activity and Selectivity of Hydrocracking Cataly." Kataliz v promyshlennosti 19, no. 3 (May 17, 2019): 235–39. http://dx.doi.org/10.18412/1816-0387-2019-3-235-239.

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Sulfur resistance of nickel, platinum and palladium metals on acid supports was studied depending on the support nature. Catalysts comprising nickel, platinum, palladium metals and sulfides as hydro-dehydrogenating components were examined for hydrocracking of n-octane. HY, ZSM-5, ZSM-23, ZSM-12, as well as silicoaluminophosphates SAPO-11 and SAPO-31 were used as the supports. The sulfur resistance of the supported metals in the catalysts was shown different and independent of the properties of the acidic support under the reaction conditions. Hydrocracking follows two different pathways depending on the activity and nature of the hydro-, dehydrogenating component (a metal or the sulfide), as well as on the ratio of activities of the acidic and hydrogenating components. The first pathway is preferable cracking of the initial paraffin at the early stage, and the second is dehydrogenation of the initial paraffin.

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25

Tobimatsu, Yuki, Toshiyuki Takano, Hiroshi Kamitakahara, and Fumiaki Nakatsubo. "Studies on the dehydrogenative polymerizations of monolignol β-glycosides. Part 2: Horseradish peroxidase-catalyzed dehydrogenative polymerization of isoconiferin." Holzforschung 60, no. 5 (August 1, 2006): 513–18. http://dx.doi.org/10.1515/hf.2006.085.

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Abstract Dehydrogenative polymerization of isoconiferin (IC; coniferyl alcohol γ-O-β-D-glucopyranoside) catalyzed by horseradish peroxidase (HRP) was carried out. The polymerization of IC proceeded in a homogeneous system, resulting in a water-soluble dehydrogenation polymer (IC-DHP). The degree of polymerization (DP) of IC-DHP was significantly higher than that of a standard dehydrogenative polymer (CA-DHP) obtained from coniferyl alcohol (CA) in a heterogeneous system. Under optimum conditions, the DP of IC-DHP was 44 (M n=1.5×104), whereas that for CA-DHP was only 11 (M n=3.0×103, as acetate). Spectroscopic analyses confirmed that IC-DHP has a lignin-like structure containing D-glucose moieties attached to the lignin side-chains. The D-glucose unit introduced into γ-O position of CA essentially influenced the water solubility and molecular mass of the resulting DHP.

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26

Wang, Jian, He Liu, Shiguang Fan, Shuai Wang, Guanjun Xu, Aijun Guo, and Zongxian Wang. "Dehydrogenation of Cycloalkanes over N-Doped Carbon-Supported Catalysts: The Effects of Active Component and Molecular Structure of the Substrate." Nanomaterials 11, no. 11 (October 26, 2021): 2846. http://dx.doi.org/10.3390/nano11112846.

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Efficient dehydrogenation of cycloalkanes under mild conditions is the key to large-scale application of cycloalkanes as a hydrogen storage medium. In this paper, a series of active metals loaded on nitrogen-doped carbon (M/CN, M = Pt, Pd, Ir, Rh, Au, Ru, Ag, Ni, Cu) were prepared to learn the role of active metals in cycloalkane dehydrogenation with cyclohexane as the model reactant. Only Pt/CN, Pd/CN, Rh/CN and Ir/CN can catalyze the dehydrogenation of cyclohexane under the set conditions. Among them, Pt/CN exhibited the best catalytic activity with the TOF value of 269.32 h−1 at 180 °C, followed by Pd/CN, Rh/CN and Ir/CN successively. More importantly, the difference of catalytic activity between these active metals diminishes with the increase in temperature. This implies that there is a thermodynamic effect of cyclohexane dehydrogenation with the synthetic catalysts, which was evidenced by the study on the activation energy. In addition, the effects of molecular structure on cycloalkane dehydrogenation catalyzed by Pt/CN were studied. The results reveal that cycloalkane dehydrogenation activity and hydrogen production rate can be enhanced by optimizing the type, quantity and position of alkyl substituents on cyclohexane.

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27

Li, Chunyi, and Guowei Wang. "Dehydrogenation of light alkanes to mono-olefins." Chemical Society Reviews 50, no. 7 (2021): 4359–81. http://dx.doi.org/10.1039/d0cs00983k.

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28

Zhao, Ning, Jianxin Zou, Xiaoqin Zeng, and Wenjiang Ding. "Mechanisms of partial hydrogen sorption reversibility in a 3NaBH4/ScF3 composite." RSC Advances 8, no. 17 (2018): 9211–17. http://dx.doi.org/10.1039/c8ra00429c.

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29

Choudhuri, Indrani, Arup Mahata, and Biswarup Pathak. "Additives in protic–hydridic hydrogen storage compounds: a molecular study." RSC Adv. 4, no. 95 (2014): 52785–95. http://dx.doi.org/10.1039/c4ra09778e.

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30

Garidzirai, Rudaviro, Phillimon Modisha, and Dmitri Bessarabov. "Assessment of Reaction Kinetics for the Dehydrogenation of Perhydro-Dibenzyltoluene Using Mg- and Zn-Modified Pt/Al2O3 Catalysts." Catalysts 14, no. 1 (December 29, 2023): 32. http://dx.doi.org/10.3390/catal14010032.

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The catalysts utilized for the dehydrogenation of dibenzyltoluene-based liquid organic hydrogen carriers (LOHCs) remain crucial. The state-of-the-art catalyst for dehydrogenation of dibenzyltoluene-based LOHC still suffers from deactivation and by-product formation. This is crucial in terms of the efficiency of the industrial dehydrogenation plant for hydrogen production, cyclability as well as the cost of replacing the catalyst. The development of catalysts with optimum performance, minimum deactivation and low by-product formation is required to attain the full benefits of the LOHC technology. Therefore, in this study, the effect of Mg and Zn modification on Pt/Al2O3 catalyst is investigated for the catalytic dehydrogenation of perhydro-dibenzyltoluene (H18-DBT). In addition, an assessment of reaction kinetics is also conducted. High dehydrogenation performance was obtained for Mg-doped Pt/Al2O3 using a batch reactor at 300 °C and 6 h reaction time. In this case, the degree of dehydrogenation (dod), productivity and conversion obtained are 100%, 1.84 gH2/gPt/min and 99.9%, respectively. Moreover, the Mg-doped catalyst has resulted in a high turnover frequency (TOF) of 586 min−1 compared to the Zn-doped catalyst (269 min−1) and the undoped catalyst (202 min−1) at the reaction temperature of 300 °C. The amount of by-products increased with an increase in the catalytic activity, with the Pt/Mg-Al2O3 catalyst possessing the highest amount of by-products. The dehydrogenation of H18-DBT followed first-order reaction kinetics. In addition, the activation energy obtained using the Arrhenius model is 102, 130 and 151 kJ/mol for Pt/Al2O3, Pt/Zn-Al2O3 and Pt/Mg-Al2O3, respectively. Although the Mg-doped Pt/Al2O3 shows high activation energy, the higher performance of the catalyst suggests that mass transfer limitations have no major effect on the dehydrogenation reaction under the conditions used.

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31

Sun, Yujie, Xia Yang, Yue Huang, Jianquan Li, Xinghua Cen, Wenlong Cen, Yongpeng Xia, Sheng Wei, Fen Xu, and Lixian Sun. "Sodium Alanate Dehydrogenation Properties Enhanced by MnTiO3 Nanoparticles." Journal of Nanoelectronics and Optoelectronics 15, no. 2 (February 1, 2020): 197–203. http://dx.doi.org/10.1166/jno.2020.2706.

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In this study, we investigated the influence of MnTiO3 nanoparticles additive on hydrogen released performance of NaAlH4 for the first time. The MnTiO3 nanoparticles were successfully synthesized using conventional solid-state ceramic route. It was found that the hydrogen released performance of NaAlH4 can be significantly improved by the addition of MnTiO3 nanoparticles. Meantime, the composite of NaAlH4 doped 5 wt% MnTiO3 possessed excellent dehydrogenation properties, the onset dehydrogenation temperature was only 70.6 °C, reduced by about 105 °C in comparison with the pristine NaAlH4, and approximately 5.01 wt% of hydrogen could be released from composite with temperature heated to 220 °C. The isothermal dehydrogenation test results indicated that the amount of hydrogen released by NaAlH4-5 wt% MnTiO3 composite could reach 4.4 wt% under 200 °C within 25 min. According to the analysis of X-ray diffraction, the presence of MnTiO3 nanoparticles did not alter the overall dehydrogenation pathway of NaAlH4, and the Al3 Ti phases formed after dehydrogenation, which enhanced hydrogen desorption performances of NaAlH4 .

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32

Yang, Zhuxian, Dan Zhou, Binling Chen, Zongjian Liu, Qinghua Xia, Yanqiu Zhu, and Yongde Xia. "Improved hydrogen release from ammonia borane confined in microporous carbon with narrow pore size distribution." Journal of Materials Chemistry A 5, no. 29 (2017): 15395–400. http://dx.doi.org/10.1039/c7ta02461d.

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33

Dai, Bing, Mingming Li, Yu Yang, Lei Shao, and Zongshu Zou. "Efficiently Removing Hydrogen of H-Supersaturated Liquid Steel in the Vacuum Degasser with Various Gas Injection Modes." Metals 13, no. 7 (July 3, 2023): 1229. http://dx.doi.org/10.3390/met13071229.

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Hydrogen removal of H-supersaturated liquid steel produced in a hydrogen-rich environment in an industrial vacuum degasser (VD) is simulated here using a two-phase (argon–steel) Eulerian model. The dehydrogenation efficiency is evaluated for a series of ladle plug layouts and argon-purging modes. Increasing the plug number from the prototype double-plug of the ladle to four or slightly prolonging the degassing time of a triple-plug ladle enables to obtain the specified dehydrogenation efficiency and the end-point hydrogen level. Varying the plug position of the triple-plug ladle makes no significant difference in the dehydrogenation efficiency, which, however, is improved by adjusting the plug angle. For the triple-plug ladle, the non-uniform argon-purging mode improves the melt hydrodynamic conditions, but the optimal dehydrogenation performance is achieved in the uniform mode. The plug number has the greatest impact on the dehydrogenation efficiency compared to the other ladle designs considered. The high-efficiency dehydrogenation of H-supersaturated liquid steel in the VD can be achieved through using the quadruple plugs, or by using the triple plugs positioned at 0.57R, 0.57R, and 0.41R and the angles of 108.6° and 71.4°, with the uniform argon-purging flow rate.

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Sun, He, Juping Zhang, Kongzhai Li, Hua Wang, and Xing Zhu. "Efficient Oxidative Dehydrogenation of Ethylbenzene over K/CeO2 with Exceptional Styrene Yield." Catalysts 13, no. 4 (April 21, 2023): 781. http://dx.doi.org/10.3390/catal13040781.

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Oxidative dehydrogenation (ODH) is an alternative for styrene (ST) production compared to the direct dehydrogenation process. However, ODH with O2 or CO2 suffers from either over-oxidation or endothermic property/low ethylbenzene conversion. Herein, we proposed an ODH process with a CO2-O2 mixture atmosphere for the efficient conversion of ethylbenzene (EB) into styrene. A thermoneutral ODH is possible by the rationalizing of CO2/O2 molar ratios from 0.65 to 0.66 in the temperature range of 300 to 650 °C. K modification is favorable for ethylbenzene dehydrogenation, and 10%K/CeO2 achieved the highest ethylbenzene dehydrogenation activity due to the enhanced oxygen mobility and CO2 adsorbability. The catalyst achieved 90.8% ethylbenzene conversion and 97.5% styrene selectivity under optimized conditions of CO2-4O2 oxidation atmosphere, a temperature of 500 °C, and a space velocity of 5.0 h−1. It exhibited excellent catalytic and structural stability during a 50 h long-term test. CO2 induces oxygen vacancies in ceria and promotes oxygen exchange between gaseous oxygen and ceria. The ethylbenzene dehydrogenation in CO2-O2 follows a Mars-van Krevelen (MvK) reaction mechanism via Ce3+/Ce4+ redox pairs. The proposed ODH strategy by using oxygen vacancies enriched catalysts offers an important insight into the efficient dehydrogenation of ethylbenzene at mild conditions.

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35

Zhang, Yi, Yongfeng Liu, Xin Zhang, You Li, Mingxia Gao, and Hongge Pan. "Mechanistic understanding of CoO-catalyzed hydrogen desorption from a LiBH4·NH3–3LiH system." Dalton Transactions 44, no. 32 (2015): 14514–22. http://dx.doi.org/10.1039/c5dt02148k.

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36

Fairuzov, Danis, Ilias Gerzeliev, Anton Maximov, and Evgeny Naranov. "Catalytic Dehydrogenation of Ethane: A Mini Review of Recent Advances and Perspective of Chemical Looping Technology." Catalysts 11, no. 7 (July 9, 2021): 833. http://dx.doi.org/10.3390/catal11070833.

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Dehydrogenation processes play an important role in the petrochemical industry. High selectivity towards olefins is usually hindered by numerous side reactions in a conventional cracking/pyrolysis technology. Herein, we show recent studies devoted to selective ethylene production via oxidative and non-oxidative reactions. This review summarizes the progress that has been achieved with ethane conversion in terms of the process effectivity. Briefly, steam cracking, catalytic dehydrogenation, oxidative dehydrogenation (with CO2/O2), membrane technology, and chemical looping are reviewed.

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37

Wong, Siew Hoon, Stephen G. Bell, and James J. De Voss. "P450 catalysed dehydrogenation." Pure and Applied Chemistry 89, no. 6 (June 27, 2017): 841–52. http://dx.doi.org/10.1515/pac-2016-1216.

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Abstract Cytochrome P450s belong to a superfamily of enzymes that catalyse a wide variety of oxidative transformations. Hydroxylation is one the most thoroughly investigated of all identified P450-catalysed reactions whilst dehydrogenation has been relatively much less explored to date. P450-catalysed dehydrogenation is often found to occur with hydroxylation and thus, it was initially suspected to be a stepwise process consisting of hydroxylation and subsequent dehydration to yield the final olefin product. This theory has been proven to be invalid and the olefin was shown to be the direct product of a P450-catalysed reaction. This interesting reaction plays a vital role in the metabolism of xenobiotics and the biosynthesis of endogenous compounds, including a number of steroids. A number of well-known examples of P450 mediated dehydrogenation, including those in the metabolism of valproic acid, capsaicin and 3-methylindole and those in the biosynthesis of plant and fungal sterols are discussed in this review.

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38

Bhosle, V., E. G. Baburaj, M. Miranova, and K. Salama. "Dehydrogenation of TiH2." Materials Science and Engineering: A 356, no. 1-2 (September 2003): 190–99. http://dx.doi.org/10.1016/s0921-5093(03)00117-5.

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39

Dasireddy, Venkata D. B. C., Faiza B. Khan, K. Bharuth-Ram, Sooboo Singh, and Holger B. Friedrich. "Non oxidative and oxidative dehydrogenation of n-octane using FePO4: effect of different FePO4 phases on the product selectivity." Catalysis Science & Technology 10, no. 22 (2020): 7591–600. http://dx.doi.org/10.1039/d0cy01585g.

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40

Wallis, Christopher J., Hellen Dyer, Laure Vendier, Gilles Alcaraz, and Sylviane Sabo-Etienne. "Dehydrogenation of Diamine-Monoboranes to Cyclic Diaminoboranes: Efficient Ruthenium-Catalyzed Dehydrogenative Cyclization." Angewandte Chemie International Edition 51, no. 15 (February 15, 2012): 3646–48. http://dx.doi.org/10.1002/anie.201108874.

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41

Wallis, Christopher J., Hellen Dyer, Laure Vendier, Gilles Alcaraz, and Sylviane Sabo-Etienne. "Dehydrogenation of Diamine-Monoboranes to Cyclic Diaminoboranes: Efficient Ruthenium-Catalyzed Dehydrogenative Cyclization." Angewandte Chemie 124, no. 15 (February 15, 2012): 3706–8. http://dx.doi.org/10.1002/ange.201108874.

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42

Klein, Robert F. X., Václav Horák, and Godfrey A. S. Baker. "Novel Dehydrogenation of 2,5-Diaryl Substituted ∆2-Oxazolines to Oxazoles." Collection of Czechoslovak Chemical Communications 58, no. 7 (1993): 1631–35. http://dx.doi.org/10.1135/cccc19931631.

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The dehydrogenation of various 2,5-diaryl substituted ∆2-oxazolines with either Br2/LiBr/CaCO3 (molar ratio 1.05 : 2 : 3) or CuBr2/LiBr/CaCO3 (molar ratio 2 : 1 : 3) in refluxing o-dichlorobenzene gives the corresponding oxazole up to 87% yield. Free radical benzylic bromination followed by dehydrobromination is the expected dehydrogenation mechanism. The successful application of the reagent combination for this transformation is in contrast to standard dehydrogenation reagents, including N-bromosuccinimide, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone, chloranil, NiO2 and active γ-MnO2.

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43

Yao, Suyang, Yanxi Pu, Lulu Ren, Manli Cao, and Baohui Ye. "Photooxidative Dehydrogenation of Chiral Ir (III) Amino Acid Complexes Based on [Λ-Ir(ppy)2(MeCN)2](PF6)." Inorganics 11, no. 10 (September 25, 2023): 380. http://dx.doi.org/10.3390/inorganics11100380.

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Octahedral chiral-at-metal Ir(III) complexes exhibit excellent structural stability and stereoselectivity in asymmetric synthesis. Selectively oxidative dehydrogenation of amino acids could be achieved by exploiting such complexes as chiral templates. The obtaining stable imine complexes can then be utilized in nucleophilic additions to generate corresponding chiral amine compounds. In this study, a conveniently synthesized [Λ-Ir(ppy)2(MeCN)2](PF6) chiral complex (ppy is 2-phenylpyridine) was utilized as a chiral template. A series of chiral amino acid complexes Λ-[Ir(ppy)2(D/L-AA)] (AA is amino acid) were prepared in high yield and optical purity. The above amino acid complexes were then oxidized to their corresponding imino acid complexes Λ-[Ir(ppy)2(AA-2H)] under visible light. All these complexes exhibited high selectivity during the dehydrogenation process without the formation of C-N bond coupling byproducts. The photooxidative dehydrogenation rates of these complexes were studied, which show that D-configured amino acids exhibited faster dehydrogenation rates when using the Λ-configured complex as a chiral template and the substitution of electron-donating or bulky groups in the N-α position of the amino acid decreased their dehydrogenation rates. The crystal structures of Λ-Ir(ppy)2(D-Thr) (Thr is threonine) and its dehydrogenated complex Λ-Ir(ppy)2(Thr-2H) indicate the process of photooxidative dehydrogenation and the configuration stability of metal center throughout the process.

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44

Aghayeva, N. I., and S. A. Mammadkhanova. "DEPENDENCE OF ACTIVITY OF BINARY Mo-V-O CATALYSTS IN THE REACTION OF DEHYDROGENATION AND OXIDATION OF ISOPROPYL ALCOHOL ON ACIDIC SURFACE PROPERTIES." Chemical Problems 21, no. 4 (2023): 388–95. http://dx.doi.org/10.32737/2221-8688-2023-4-388-395.

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The reaction of dehydrogenation and oxidative dehydrogenation of isopropyl alcohol on molybdenum-vanadium oxide catalysts has been studied. It found that the dependences of isopropyl alcohol conversion and propylene yields on the atomic ratio of molybdenum to vanadium in reaction of dehydrogenation of isopropyl alcohol have the form of a curve with two maxima on samples Mo-V=2-8 and Mo-V=6-4. To characterize the acidic properties of the surface of molybdenum-vanadium oxide catalysts, their activity in the reaction of butene-1 isomerization into butenes-2 was also studied. It showed that on molybdenum-vanadium catalysts the dependence of the yield of 2-butenes on the ratio of molybdenum to vanadium also had the form of a curve with two maxima. The activities of molybdenumvanadium oxide catalysts were compared with their acidic properties. It revealed that on binary molybdenum-vanadium oxide catalysts in the reaction of isopropyl alcohol dehydrogenation the increase of surface acidity led to the increase in acetone yield and the decrease in propylene yield. In the reaction of oxidative dehydrogenation of isopropyl alcohol, the increase in surface acidity led to the increase in acetone yield, while propylene yield practically did not change.

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45

Nguyen, Thu D., Weiqing Zheng, Fuat E. Celik, and George Tsilomelekis. "CO2-assisted ethane oxidative dehydrogenation over MoOx catalysts supported on reducible CeO2–TiO2." Catalysis Science & Technology 11, no. 17 (2021): 5791–801. http://dx.doi.org/10.1039/d1cy00362c.

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Supported MoOx catalysts on mixed CeO2–TiO2 were investigated for the oxidative dehydrogenation of ethane (ODHE) using CO2 as a mild oxidant. The reducibility of the support and nature of MoOx affect the relative dehydrogenation pathways.

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46

Wu, Zhenwei, Evan C. Wegener, Han-Ting Tseng, James R. Gallagher, James W. Harris, Rosa E. Diaz, Yang Ren, Fabio H. Ribeiro, and Jeffrey T. Miller. "Pd–In intermetallic alloy nanoparticles: highly selective ethane dehydrogenation catalysts." Catalysis Science & Technology 6, no. 18 (2016): 6965–76. http://dx.doi.org/10.1039/c6cy00491a.

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2 nm PdIn intermetallic alloy (cubic, CsCl type) nanoparticle catalyst was near 100% selective to ethane dehydrogenation at 600 °C (at 15% conversion) with a dehydrogenation TOR almost 10 times higher than that of monometallic Pd.

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47

BARNES, C. J., M. VALDEN, and M. PESSA. "THE UNUSUAL ADSORPTION BEHAVIOUR OF BENZENE ON ${\rm Co}(10{\bar 1}0)$." Surface Review and Letters 07, no. 01n02 (February 2000): 67–74. http://dx.doi.org/10.1142/s0218625x00000105.

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Adsorption of benzene on (10[Formula: see text] leads to formation of an ordered p(3 × 1) monolayer. ARPES measurements combined with adlayer density considerations indicate that the [Formula: see text] monolayer consists of molecules whose symmetry has been reduced to C1 consistent with a partially dehydrogenated tilted cyclic C6 intermediate (phenyl or C6H4). Desorption measurements in conjunction with ARPES indicate that a stepwise dehydrogenation of the ring occurs with the dehydrogenation step above room temperature at ~ 380 K corresponding to formation of small well-oriented CxHy (x, y = 1 or 2) hydrocarbon fragment(s) (possibly C2H and CH) resulting from ring opening. Complete dehydrogenation occurs for temperatures above 550 K, leaving a carbonaceous residue. The low dehydrogenation and decomposition temperatures indicate [Formula: see text]0) to be particularly active towards both C–H bond scission and ring opening.

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48

Lee, Gil Jae, Jae Hyeok Shim, Young Whan Cho, and Kyung Sub Lee. "Catalytic Effect of Ti₅Si₃ on Dehydrogenation of NaAlH₄." Solid State Phenomena 124-126 (June 2007): 951–54. http://dx.doi.org/10.4028/www.scientific.net/ssp.124-126.951.

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Fine Ti5Si3 powder has been synthesized from a mixture of elemental Ti and Si powders using a mechanochemical method. It shows a good catalytic effect on NaAlH4 by reducing the dehydrogenation temperature and improving the dehydrogenation kinetics. Although the catalytic effect of Ti5Si3 is not better than that of TiCl3, the Ti5Si3 catalyst has an advantage over TiCl3 in terms of hydrogen capacity by releasing more hydrogen than TiCl3 during dehydrogenation. NaAlH4 catalyzed with Ti5Si3 shows reversible hydrogen storage by being hydrogenated at moderate conditions, although the hydrogenation kinetics is rather slow.

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49

Pal, Tanay, Premananda Ghosh, Minhajul Islam, Srimanta Guin, Suman Maji, Suparna Dutta, Jayabrata Das, Haibo Ge, and Debabrata Maiti. "Tandem dehydrogenation-olefination-decarboxylation of cycloalkyl carboxylic acids via multifold C–H activation." Nature Communications 15, no. 1 (June 25, 2024). http://dx.doi.org/10.1038/s41467-024-49359-x.

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AbstractDehydrogenation chemistry has long been established as a fundamental aspect of organic synthesis, commonly encountered in carbonyl compounds. Transition metal catalysis revolutionized it, with strategies like transfer-dehydrogenation, single electron transfer and C–H activation. These approaches, extended to multiple dehydrogenations, can lead to aromatization. Dehydrogenative transformations of aliphatic carboxylic acids pose challenges, yet engineered ligands and metal catalysis can initiate dehydrogenation via C–H activation, though outcomes vary based on substrate structures. Herein, we have developed a catalytic system enabling cyclohexane carboxylic acids to undergo multifold C–H activation to furnish olefinated arenes, bypassing lactone formation. This showcases unique reactivity in aliphatic carboxylic acids, involving tandem dehydrogenation-olefination-decarboxylation-aromatization sequences, validated by control experiments and key intermediate isolation. For cyclopentane carboxylic acids, reluctant to aromatization, the catalytic system facilitates controlled dehydrogenation, providing difunctionalized cyclopentenes through tandem dehydrogenation-olefination-decarboxylation-allylic acyloxylation sequences. This transformation expands carboxylic acids into diverse molecular entities with wide applications, underscoring its importance.

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50

Gao, Shuo, Wentao Hao, Yuqi Ji, Xiulin Li, Chunyan Zhang, and Guoying Zhang. "Co‐Catalyzed Dehydrogenation Claisen Condensation of Secondary Alcohols with Esters^†." Chinese Journal of Chemistry, July 17, 2024. http://dx.doi.org/10.1002/cjoc.202400481.

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Comprehensive SummaryCatalytic dehydrogenation, with its exceptional atom economy and chemoselectivity, offers a highly desirable yet challenging approach for converting multiple environmentally friendly alcohols into crucial molecules. Furthermore, the utilization of catalysts based on abundant elements found on Earth for alcohol dehydrogenation to produce acryl ketone holds significant promise as a versatile strategy in synthesizing key building blocks for numerous pharmaceutical applications. The present study describes a practical Co‐catalyzed cascade dehydrogenative Claisen condensation of secondary alcohols with esters, facilitating the synthesis of a wide range of 3‐hydroxy‐prop‐2‐en‐1‐ones. We introduce a catalytic system based on novel and scalable indazole NNP‐ligands coordinated to cobalt for efficient dehydrogenations of secondary alcohols, and propose a plausible reaction mechanism supported by control experiments and labeling studies. Notably, it allows for the streamlined synthesis of multiple pharmaceuticals in one‐pot.

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