9003-41-2Relevant academic research and scientific papers
Synthesis and Oxidation Catalysis of [Tris(oxazolinyl)borato]cobalt(II) Scorpionates
Reinig, Regina R.,Mukherjee, Debabrata,Weinstein, Zachary B.,Xie, Weiwei,Albright, Toshia,Baird, Benjamin,Gray, Tristan S.,Ellern, Arkady,Miller, Gordon J.,Winter, Arthur H.,Bud'ko, Sergey L.,Sadow, Aaron D.
, p. 2486 - 2494 (2016)
The reaction of CoCl2·THF and thallium tris(4,4-dimethyl-2-oxazolinyl)phenylborate (TlToM) in tetrahydrofuran (THF) provides ToMCoCl (1) in 95 % yield; however, appropriate solvents and starting materials are required to favor 1 over two other readily formed side-products, (ToM)2Co (2) and {HToM}CoCl2(3). ESR, NMR, FTIR, and UV/Vis spectroscopies were used to distinguish these cobalt(II) products and probe their electronic and structural properties. Even after the structures indicated by these methods were confirmed by X-ray crystallography, the spectroscopic identification of trace contaminants in the material was challenging. The recognition of possible contaminants in the synthesis of ToMCoCl in combination with the paramagnetic nature of these complexes provided impetus for the utilization of X-ray powder diffraction to measure the purity of the ToMCoCl bulk sample. The X-ray powder diffraction results provide support for the bulk-phase purity of ToMCoCl in preparations that avoid 2 and 3. Thus, 1 is a precursor for new [tris(oxazolinyl)borato]cobalt chemistry, as exemplified by its reactions with KOtBu and NaOAc to give ToMCoOtBu (4) and ToMCoOAc (5), respectively. Compound 5 is a catalyst for the oxidation of cyclohexane with meta-chloroperoxybenzoic acid (mCPBA), and the rate constants and selectivity for cyclohexanol versus cyclohexanone and ε-caprolactone were assessed.
Efficient and selective oxidation of hydrocarbons with tert-butyl hydroperoxide catalyzed by oxidovanadium(IV) unsymmetrical Schiff base complex supported on γ-Fe2O3 magnetic nanoparticles
Ardakani, Mehdi Hatefi,Sabet, Mohammad,Samani, Mahnaz
, (2022/01/22)
The catalytic activity of an oxidovanadium(IV) unsymmetrical Schiff base complex supported on γ-Fe2O3 magnetic nanoparticles, γ-Fe2O3@[VO(salenac-OH)] in which salenac-OH = [9-(2′,4′-dihydroxyphenyl)-5,8-diaza-4
An efficient method for the catalytic aerobic oxidation of cycloalkanes using 3,4,5,6-Tetrafluoro-N-Hydroxyphthalimide (F4-NHPI)
Guha, Samar K.,Ishii, Yasutaka
, p. 327 - 335 (2021/12/13)
N-Hydroxyphthalimide (NHPI) is known to be an effective catalyst for the oxidation of hydrocarbons. The catalytic activity of NHPI derivatives is generally increased by introducing an electron-withdrawing group on the benzene ring. In a previous report, two NHPI derivatives containing fluorinated alkyl chain were prepared and their catalytic activity was investigated in the oxidation of cycloalkanes. It was found that the fluorinated NHPI derivatives showed better yields for the oxidation reaction. As a continuation of our work with fluorinated NHPI derivatives, our next aim was to investigate the catalytic activity of the NHPI derivatives by introducing fluorine atoms in the benzene ring of NHPI. In the present research, 3,4,5,6-Tetrafluoro-N-Hydroxyphthalimide (F4-NHPI) is prepared and its catalytic activity has been investigated in the oxidation of two different cycloalkanes for the first time. It has been found that F4-NHPI showed higher catalytic efficiency compared with that of the parent NHPI catalyst in the present reactions. The presence of a fluorinated solvent and an additive was also found to accelerate the oxidation.
An alternative route for the preparation of phenol: Decomposition of cyclohexylbenzene-1-hydroperoxide
Yang, Yufei,Zhang, Yadong
, p. 71 - 80 (2021/09/28)
In this work, a HPW/ZSM-5 catalyst was prepared by impregnating phosphotungstic acid (HPW) with carrier ZSM-5 zeolite and characterized by XRD, SEM, N2 adsorption/desorption isotherm, NH3-TPD, and FT-IR techniques. The catalytic performance of HPW/ZSM-5 was investigated by using the decomposition reaction of cyclohexylbenzene-1-hydroperoxide (CHBHP) to phenol and cyclohexanone. The conversion rate of CHBHP was up to 97.28%. In addition, the reusability test exhibited that the high durability HPW/ZSM-5 as the conversion rate of CHBHP only decreased by 3.11% after five runs. The kinetic study of the decomposition reaction indicated it was a primary reaction. The apparent activation energy of the decomposition reaction was 102.39?kJ·mol–1 in the temperature range of 45–60℃. All results indicate that the HPW/ZSM-5 catalyst has good performance and promising applications in acid catalyzed organic chemistry.
Rational synthesis of palladium nanoparticles modified by phosphorous for the conversion of diphenyl ether to KA oil
Bai, Hong-Cun,Cao, Jing-Pei,Jiang, Wei,Wei, Yu-Lei,Xie, Jin-Xuan,Zhang, Chuang,Zhao, Liang,Zhao, Ming,Zhao, Xiao-Yan
, (2021/12/23)
Conversion of lignin-derived molecules into value-added chemicals is critical for sustainable chemistry but still challenging. Herein, phosphorus-modified palladium catalyzed the degradation of lignin-derived 4-O-5 linkage to produce KA oil (cyclohexanone-cyclohexanol oil) was reported. The reaction proceeds via a restricted partial hydrogenation-hydrolysis pathway. Phosphorus-modified palladium catalyst suppressed the full hydrogenation of diary ether, which was the key point to produce KA oil selectively. Under the optimized conditions, the 4.5 nm Pd-P NPs could catalyze the conversion of 4-O-5 linkage into KA oil in 83% selectivity with a high production rate of 32.5 mmol·g?1Pd·min?1. This study represented an original method for KA oil production.
Electrocatalytic hydrogenation of lignin monomer to methoxy-cyclohexanes with high faradaic efficiency
Chen, Henan,Kumar, Mohan,Liang, Baiyao,Peng, Tao,Wang, Miao,Yang, Chenxin,Zhang, Yun,Zhao, Wei
supporting information, p. 142 - 146 (2022/01/19)
Developing efficient renewable electrocatalytic processes in chemical manufacturing is of commercial interest, especially from biomass-derived feedstock. Selective electrocatalytic hydrogenation (ECH) of biomass-derived lignin monomers to high-value oxygen-functional compounds is promising towards achieving this goal. However, ECH has to date lacked the satisfied selectivity to upgrade lignin monomers to high-value oxygenated chemicals due to the reduction of vulnerable ?OCH3 that exists in most lignin monomers. Herein we report carbon-felt supported ternary RhPtRu catalysts with a record faradaic efficiency (FE) of 62.8% and selectivity of 91.2% to methoxy-cyclohexanes (2-methoxy-cyclohexanol and 2-methoxy-cyclohexanone) from guaiacol, via a strong inhibition effect on the cleavage of the methoxy group, representing the best performance compared to previous reports. We further conducted a brief TEA to demonstrate a profitable ECH of guaiacol to high-value methoxy-cyclohexanes using our designed RhPtRu ternary catalysts.
From Ring-Expansion to Ring-Contraction: Synthesis of γ-Lactones from Cyclobutanols and Relative Stability of Five- and Six-Membered Endoperoxides toward Organic Bases
Ferrié, Laurent,Jamey, Nicolas
, (2022/04/07)
Cyclobutanols undergo ring expansion with molecular oxygen in the presence of Co(acac)2 to afford 1,2-dioxane-hemiperoxyketals. In the course of acylation, we observed that endoperoxides rearranged into ?-lactone in the presence of triethylamine. Thus, a generalization of this ring contraction through a Kornblum DeLaMare rearrangement is here reported. Application of this transformation to monosubstituted 1,2-dioxane derivatives also led to 1,4-ketoaldehydes, in proportions depending on the nature of the substituent. These same conditions applied to five-membered dioxolane analogues led to fragmentation instead, through a retro-aldol type process. This study emphasizes the difference of stability of 1,2-dioxane and 1,2-dioxolane against organic bases, 1,2-dioxolanes having proved to be particularly reactive whereas 1,2-dioxanes showed a relative tolerance under these conditions.
Titania-supported molybdenum oxide combined with Au nanoparticles as a hydrogen-driven deoxydehydration catalyst of diol compounds
Cao, Ji,Gan, Jianxing,Hacatrjan, Schanth,Liu, Lujie,Nakagawa, Yoshinao,Tamura, Masazumi,Tomishige, Keiichi,Yabushita, Mizuho
, p. 2146 - 2161 (2022/04/28)
A heterogenous catalyst for the deoxydehydration (DODH) reaction was developed using less expensive Mo than Re as the active center. The combination of Mo with anatase-rich TiO2 and Au as the support and promoter for H2 activation, respectively, can selectively convert 1,4-anhydroerythritol to 2,5-dihydrofuran, which is a typical DODH model reaction, with H2 as a reducing agent. Loading of Au on TiO2 by the deposition-precipitation method gave the more active MoOx-Au/TiO2 catalyst (MoOx-dpAu/TiO2) than that obtained by the impregnation method (MoOx-impAu/TiO2), and the activity difference is derived from the smaller size of Au particles in MoOx-dpAu/TiO2 (3-5 nm) than that in MoOx-impAu/TiO2 (>25 nm). The MoOx-dpAu/TiO2 catalyst could be applied to the DODH reaction of linear alkyl vicinal diols and cis-1,2-cyclohexanediol. The characterization with XRD, STEM, H2-TPR, XAFS and XPS revealed that the MoIV oxide cluster species on the surface of anatase TiO2 particles are responsible for the DODH reaction.
Palladium Nanoparticles in Hypercrosslinked Polystyrene: Synthesis and Application in the Hydrogenation of Arenes
Lyubimov,Zvinchuk,Korlyukov,Davankov,Parenago
, p. 76 - 80 (2020/11/09)
Abstract: A novel method for incorporation of palladium nanoparticles into a poroushypercrosslinked polystyrene matrix has been developed. The composite obtainedby reduction of [Pd(π-allyl)Cl]2 with hydrogen insupercritical CO2 shows high catalytic activity in thehydrogenation of benzene and can be used twelve (12) times in a row without anydecrease in conversion rate. The catalyst is also suitable for quantitativehydrogenation of toluene, tetralin and phenol. The obtained catalytic system iscompared with the palladium composite synthesized by a conventional method basedon hypercrosslinked polystyrene.
Bimetallic RuPd nanoparticles in ionic liquids: Selective catalysts for the hydrogenation of aromatic compounds
Abarca, Gabriel,Goncalves, Wellington D. G.,Albuquerque, Brunno L.,Dupont, Jairton,Prechtl, Martin H. G.,Scholten, Jackson D.
supporting information, p. 98 - 103 (2021/01/11)
Bimetallic RuPd nanoparticles (NPs) immobilized in ionic liquids (ILs) were shown to be a highly active medium for the selective hydrogenation of benzene and phenol under mild conditions (4 bar H2, 60 °C) in a biphasic system (n-heptane/IL). The equimolar combination of Ru and Pd into a bimetallic particle generated a synergistic catalyst that allowed the selective production of cyclohexane (>99% selectivity, 94% conversion) and cyclohexanol (99% selectivity, >98% conversion) from the reduction of benzene and phenol, respectively. Moreover, the catalytic results revealed that the activity and selectivity are dependent on the Ru?:?Pd ratio into the bimetallic NPs.
