20664-46-4Relevant academic research and scientific papers
Selective aerobic oxidation of activated alkanes with MOFs and their use for epoxidation of olefins with oxygen in a tandem reaction
Luz,Leon,Boronat,Llabres I Xamena,Corma
, p. 371 - 379 (2013)
MOFs with Cu2+ centers linked to four nitrogen atoms from azaheterocyclic compounds, i.e., pyrimidine [Cu(2-pymo)2] and imidazole [Cu(im)2], are active catalysts for aerobic oxidation of activated alkanes, such as tetralin, cumene and ethylbenzene. Differences in activity among the two MOFs appear to be related to differences in their ability to decompose the hydroperoxide and to coordinate to the resulting radical OH species. Copper ions in [Cu(im)2] can coordinate by expanding their coordination sphere from 4 to 5 in a reversible way, while in the case of [Cu(2-pymo)2] it results in a displacement of one of the pyrimidine ligands. The MOFs can be used in combination with a silylated Ti-MCM-41 to catalyze the epoxidation of olefins with oxygen by means of a tandem reaction in which the MOF produces cumene hydroperoxide, which is used by Ti-MCM-41 to epoxidize the olefin. The Royal Society of Chemistry 2013.
Selective aerobic oxidation of allylic alcohols to carbonyl compounds using catalytic Pd(OAc)2: High intramolecular selectivity
Batt, Frédéric,Bourcet, Emmanuel,Kassab, Youssef,Fache, Fabienne
, p. 1869 - 1872 (2007)
Allylic alcohols were selectively oxidized into aldehydes or ketones using a Pd(OAc)2-Et3N-O2 system. Diols with one allylic function were selectively oxidized, with one of the hydroxyl groups remaining untouched. Georg Thieme Verlag Stuttgart.
Dispersed Ru nanoclusters transformed from a grafted trinuclear Ru complex on SiO2 for selective alcohol oxidation
Muratsugu, Satoshi,Lim, Min Hwee,Itoh, Takahiro,Thumrongpatanaraks, Wipavee,Kondo, Mio,Masaoka, Shigeyuki,Andy Hor,Tada, Mizuki
, p. 12611 - 12619 (2013)
Ru nanoclusters (average diameter = 1.3 ± 0.3 nm) were successfully prepared by using a Ru3 cluster Ru3O(CH 3COO)6(H2O)3·(CH 3COO) grafted on a pyridine-functionalized SiO2 surface. The pyridine moiety dispersed on the SiO2 surface spread the Ru 3 cluster, controlling its surface density, and the nanoclusterization of the Ru cluster proceeded on the surface. The structures of the Ru nanoclusters were characterized by means of elemental analysis; thermogravimetric analysis; FT-IR, UV/vis, and solid-state NMR spectroscopy; BET analysis; X-ray photoelectron spectroscopy; X-ray diffraction; transmission electron microscopy; and Ru K-edge X-ray absorption fine structure analysis. It was found that the catalytic activity for the selective oxidation of alcohol to the corresponding aldehyde using O2 highly depended on the dispersion and structures of the Ru particles, and the Ru nanocluster was found to be efficient in the selective oxidation of a variety of alcohols.
Radical induced disproportionation of alcohols assisted by iodide under acidic conditions
Huang, Yang,Jiang, Haiwei,Li, Teng,Peng, Yang,Rong, Nianxin,Shi, Hexian,Yang, Weiran
supporting information, p. 8108 - 8115 (2021/10/29)
The disproportionation of alcohols without an additional reductant and oxidant to simultaneously form alkanes and aldehydes/ketones represents an atom-economical transformation. However, only limited methodologies have been reported, and they suffer from a narrow substrate scope or harsh reaction conditions. Herein, we report that alcohol disproportionation can proceed with high efficiency catalyzed by iodide under acidic conditions. This method exhibits high functional group tolerance including aryl alcohol derivatives with both electron-withdrawing and electron-donating groups, furan ring alcohol derivatives, allyl alcohol derivatives, and dihydric alcohols. Under the optimized reaction conditions, a 49% yield of 5-methyl furfural and a 49% yield of 2,5-diformylfuran were obtained simultaneously from 5-hydroxymethylfurfural. An initial mechanistic study suggested that the hydrogen transfer during this redox disproportionation occurred through the inter-transformation of HI and I2. Radical intermediates were involved during this reaction.
Iodine-catalyzed alcohol disproportionation method
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Paragraph 0034-0035, (2021/06/13)
The invention relates to the technical field of catalysis, in particular to an iodine-catalyzed alcohol disproportionation method which comprises the following steps: sequentially adding alcohol, iodine and a solvent into a high-temperature and high-pressure reaction kettle, introducing a certain amount of nitrogen, conducting reacting for a certain time, collecting an organic phase after the reaction is ended, and conducting fractionating to obtain corresponding alkane and aldehyde/ketone. Alcohol disproportionation is efficient and atom-economical conversion without any additional oxidizing agent and reducing agent, and hydrocarbon and aldehyde/ketone molecules which are easy to separate can be formed at the same time. Meanwhile, the method has wide functional group tolerance, various substrate samples including aryl alcohol derivatives, heterocyclic alcohol derivatives, allyl alcohol derivatives and dihydric alcohol are tested, and the result shows that most of the substrate samples show good or extremely good yield.
Ligand coordination sphere effect of Schiff base cis-dioxomolybdenum(VI) complexes in selective catalytic oxidation of alcohols
Liu, Haiwen,Zhuo, Zihan,Zhang, Yan,Wei, Hang,Zhang, Wenxin,Li, Tong,Mao, Zuodong,Wang, Weili
, p. 1253 - 1261 (2021/08/13)
Several cis-dioxomolybdenum(VI) complexes with Schiff bases-derived ligands were synthesized and fully characterized. The catalytic performances of these complexes were tested in the alcohol oxidation under solvent-free condition using H2O2 as oxidant giving high results. The influence of the oxygen, sulfur, and nitrogen atom within the coordination sphere around the molybdenum center was studied (S?>?N?>?O). From this study, we suggest that there exists a relationship between the electronegativity of the atom and the catalytic performance in alcohol oxidation.
Accessing Frustrated Lewis Pair Chemistry through Robust Gold@N-Doped Carbon for Selective Hydrogenation of Alkynes
Fiorio, Jhonatan Luiz,Gon?alves, Renato Vitalino,Teixeira-Neto, Erico,Ortu?o, Manuel A.,López, Núria,Rossi, Liane Marcia
, p. 3516 - 3524 (2018/04/14)
Pyrolysis of Au(OAc)3 in the presence of 1,10-phenanthroline over TiO2 furnishes a highly active and selective Au nanoparticle (NP) catalyst embedded in a nitrogen-doped carbon support, Au@N-doped carbon/TiO2 catalyst. Parameters such as pyrolysis temperature, type of support, and nitrogen ligands as well as Au/ligand molar ratios were systematically investigated. Highly selective hydrogenation of numerous structurally diverse alkynes proceeded in moderate to excellent yield under mild conditions. The high selectivity toward the industrially important alkene substrates, functional group tolerance, and the high recyclability makes the catalytic system unique. Both high activity and selectivity are correlated with a frustrated Lewis pairs interface formed by the combination of gold and nitrogen atoms of N-doped carbon that, according to density functional theory calculations, can serve as a basic site to promote the heterolytic activation of H2 under very mild conditions. This "fully heterogeneous" and recyclable gold catalyst makes the selective hydrogenation process environmentally and economically attractive.
Selective Aerobic Oxidation of Alcohols with NO3? Activated Nitroxyl Radical/Manganese Catalyst System
Lagerblom, Kalle,Keskiv?li, Juha,Parviainen, Arno,Mannisto, Jere,Repo, Timo
, p. 2908 - 2914 (2018/05/03)
A homogeneous Mn(NO3)2/2,2,6,6-tetramethylpiperidin-1-yl)oxyl/2-picolinic acid catalyst system is highly active and versatile for the selective aerobic oxidation of alcohols (2,2,6,6-tetramethylpiperidin-1-yl)oxyl=TEMPO, 2-picolinic acid=PyCOOH). The catalytic method enables near quantitative conversion of various primary alcohols to the respective aldehydes using a very simple reaction setup and workup. This study presents findings on the catalyst stability and mechanisms of deactivation. The results show that NO3? plays a crucial catalytic role in the reaction as a source of oxygen activating NOx species. Yet, disproportionation of NO3? to the volatile NO2 during the reaction leads to catalyst deactivation under open air conditions. Catalyst deactivation through this route can be overcome by adding a catalytic amount of nitrate salt, for example NaNO3 into the reaction. This stabilizes the Mn(NO3)2/TEMPO/PyCOOH catalyst and enables oxidation of various primary alcohols to the respective aldehydes using low catalyst loadings under ambient conditions. Secondary alcohols can be oxidized with a modified catalyst utilizing sterically accessible nitroxyl radical 9-azabicyclo[3.3.1]nonane N-oxyl (ABNO) instead of TEMPO. At the end of the alcohol oxidation, pure carbonyl products and the reusable catalyst can be recovered simply by extracting with organic solvent and dilute aqueous acid, followed by evaporation of both phases.
On the Use of Polyelectrolytes and Polymediators in Organic Electrosynthesis
Schille, Benjamin,Giltzau, Niels Ole,Francke, Robert
supporting information, p. 422 - 426 (2018/02/21)
Although organic electrosynthesis is generally considered to be a green method, the necessity for excess amounts of supporting electrolyte constitutes a severe drawback. Furthermore, the employment of redox mediators results in an additional separation problem. In this context, we have explored the applicability of soluble polyelectrolytes and polymediators with the TEMPO-mediated transformation of alcohols into carbonyl compounds as a test reaction. Catalyst benchmarking based on cyclic voltammetry studies indicated that the redox-active polymer can compete with molecularly defined TEMPO species. Alcohol oxidation was also highly efficient on a preparative scale, and our polymer-based approach allowed for the separation of both mediator and supporting electrolyte in a single membrane filtration step. Moreover, we have shown that both components can be reused multiple times.
Chemoenzymatic one-pot reaction of noncompatible catalysts: Combining enzymatic ester hydrolysis with Cu(i)/bipyridine catalyzed oxidation in aqueous medium
Sand, Henning,Weberskirch, Ralf
, p. 33614 - 33626 (2017/07/12)
The combination of chemical catalysts and biocatalysts in a one-pot reaction has attracted considerable interest in the past years. However, since each catalyst requires very different reaction conditions, chemoenzymatic one-pot reactions in aqueous media remain challenging and are limited today to metal-catalysts that display high activity in aqueous media. Here, we report the first combination of two incompatible catalytic systems, a lipase based ester hydrolysis with a water-sensitive Cu/bipyridine catalyzed oxidation reaction, in a one-pot reaction in aqueous medium (PBS buffer). Key to the solution was the compartmentalization of the Cu/bipyridine catalyst in a core-shell like nanoparticle. We show the synthesis and characterization of the Cu/bipyridine functionalized nanoparticles and the application in the oxidation of allylic and benzylic alcohols in aqueous media. Furthermore, the work demonstrates the implementation of a one-pot reaction process with optimized reaction conditions involving a lipase (CAL-B) to hydrolyze various acetate ester substrates in the first step, followed by oxidation of the resulting alcohols to the corresponding aldehydes under aerobic conditions in aqueous media.
