Reaction Kinetics Mechanisms and Catalysis
·
2013
·Vol. 109
·期 2
·551-562
·
IF 1.104
Cui Wenjing,Zhu Huaiyong,Jia Meilin,Ao Wulan,Zhang Yulin,Zhaorigetu Bao
Imines were synthesized from benzyl alcohol and amines by using catalysts of gold nanoparticles supported on ZrO 2 (Au/ZrO 2 ). The effects of reaction time, temperature, gold loadings and base were investigated. High yields were achieved under moderate conditions (60 °C) in the presence of KOCH 3 . For instance, the yield of N -benzylidenebenzylamine produced from benzyl alcohol and benzylamine on 3 wt% Au/ZrO 2 is 87 %. The synthesis of imine involves two reaction steps: selective oxidation of benzyl alcohol to benzaldehyde and the coupling reaction of amines with benzaldehyde. In the first step, the base promotes the selective oxidation. The reactions of benzyl alcohol with three different amines, aniline, n -butylamine and benzylamine, were conducted to produce corresponding imines. The results show that the amine with stronger nucleophilicity has better ability to react with benzaldehyde in the second step, resulting in higher yield of the corresponding imine. We proposed a tentative mechanism for the synthesis process.
研究领域:
催化化学
·
有机合成
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2013
·
IF 3.41
Jing Chen,Shijun Huang,Jin Lin,Weiping Su
Using a supported palladium catalytic system, the reaction of nitroarenes with benzyl alcohols occurred smoothly via hydrogen transfer to produce imines in an atom-economical manner. The palladium species were dispersed well on hydrotalcite (HT) support and palladium nanoparticles with size of about 3.5 nm were formed during reaction. Both of the small size of palladium nanoparticles and the rich hydroxyl groups on HT surface enhanced the catalytic performance of Pd/HT. The catalytic system is recyclable and amenable to a variety of aromatic alcohols and nitro compounds.
研究领域:
化学
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2019
·
IF 1.911
Fushan Chen,Songlin Zhao,Tao Yang,Taotao Jiang,Jun Ni,Houfeng Xiong,Qunfeng Zhang,Xiaonian Li
A novel template-free oxalate route was applied to synthesize different mesoporous manganese oxides (amorphous manganese oxide (AMO), Mn 5 O 8 , Mn 3 O 4 , MnO 2 ) in the narrow temperature range from 350 °C to 400 °C by controlling the calcination conditions, which were employed as the efficient catalysts for the oxidative coupling of imines from alcohols and amines. The chemical and structural properties of the manganese oxides were characterized by the methods of thermal analysis and heat flow (TG-DSC), X-ray diffraction (XRD), nitrogen sorption , scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), H 2 temperature-programmed reduction (H 2 -TPR), and inductively coupled plasma optical emission spectrometry (ICP-OES) techniques. The structures of different manganese oxides were confirmed by characterization. The M-350 (AMO) presented the maximum surface area, amorphous nature, the lowest reduction temperature, the higher (Mn 3+ + Mn 4+ )/Mn 2+ ratio, and the higher adsorbed oxygen species compared to other samples. Among the catalysts, M-350 showed the best catalytic performance using air as an oxidant, and the conversion of benzyl alcohol (BA) and the selectivity of N -benzylideneaniline (NBA) reached as high as 100% and 97.1% respectively at the lower reaction temperature (80 °C) for 1 h. M-350 had also the highest TOF value (0.0100 mmol·mg −1 ·h −1 ) compared to the other manganese oxide catalysts. The catalyst was reusable and gave 95.8% conversion after 5 reuse tests, the XRD pattern of the reactivated M-350 did not show any obvious change. Lattice oxygen mobility and (Mn 3+ + Mn 4+ )/Mn 2+ ratio were found to play the important roles in the catalytic activity of aerobic reactions.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Rong Shang,Qizhao Zhang,Peng Lin,Bang Gu,Qinghu Tang,Qiue Cao,Wenhao Fang
Direct oxidative coupling of alcohols and amines is an environmental-benign and atomic-economy approach for imine synthesis. We disclosed that UiO-66 framework successfully confined Ru to single-atom scale with assistance of oxophilic Zn 2+ promoter. This RuZn@UiO-66 catalyst showed a highest TOF of 78 h -1 among all Ru catalysts in literature and attained > 99% yield to benzylideneaniline in the model reaction in an O 2 atmosphere at a low temperature without alkaline additives. In addition, this catalyst demonstrated satisfying gram-scale imine synthesis, wide substrate scope and stable reusability. Kinetic investigations and in situ characterizations allowed getting insights to active sites, amphoteric carrier and reaction mechanism. Dynamic interactions between Ru and Zn based on their ratios induced electron-deficient Ru 0 active sites promoted by oxophilic Zn 2+ species. Hence, primary alcohols can be efficiently converted to the corresponding aldehydes using molecular O 2 , i.e. , the rate-determining step. Besides, Zr 4+ -O 2- pairs on UiO-66 provided adequate acidic-basic sites for the tandem catalysis.
研究领域:
催化化学
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材料科学
·
环境化学
✓ 已验证
产品关联
DOI
高影响因子
iScience
·
2023
·
IF 5.8
Cheng Wang,Zirui Qiao,Yulan Tian,Haijun Yang,Huaqiang Cao,Anthony K. Cheetham
Imines are important intermediates for synthesizing various fine chemicals, with the disadvantage of requiring the use of expensive metal-containing catalysts. We report that the dehydrogenative cross-coupling of phenylmethanol and benzylamine (or aniline) directly forms the corresponding imine with a yield of up to 98%, and water as the sole by-product, in the presence of a stoichiometric base, using carbon nanostructures as the “green” metal-free carbon catalysts with high spin concentrations, which is synthesized by C(sp 2 )-C(sp 3 ) free radical coupling reactions. The catalytic mechanism is attributed to the unpaired electrons of carbon catalysts to reduce O 2 to O 2 ·− , which triggers the oxidative coupling reaction to form imines, whereas the holes in the carbon catalysts receive electrons from the amine to restore the spin states. This is supported by density functional theory calculations. This work will open up an avenue for synthesizing carbon catalysts and offer great potential for industrial applications.
研究领域:
化学
·
材料科学
·
催化反应
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Ting Zhang,Wantong Zhao,Shiyan Li,Wenguang Cui,Baojun Wang,Yuefeng Liu,Riguang Zhang,Zhongkui Zhao
Selective transfer hydrogenation coupling of nitroarenes with benzyl alcohol is one of the most reliable strategies to access functionalized imines, but challenges remain, such as the multiple and complicated operate process, low reactivity, poor selectivity results from deep hydrogenation. Constructing highly efficient catalyst is critical for this organic transformation process. Herein, we propose a unique single-atom Co-N 4 sites on N-doped carbon, with significantly upshifted d -band center, fabricated by a one-pot solid-phase carbonization strategy, which generates an excellent catalyst for one-pot selective transfer hydrogenation coupling of nitroarenes with benzyl alcohol to various functionalized imines. Experimental and theoretical investigations demonstrate the clear linear correlation among the nitrobenzene turnover number ( TON ) and d -band center over the as-prepared Co based samples, indicating the vital effect of electronic structure of Co sites on catalytic performances. Furthermore, owing to the upshifted d -band center of Co-N 4 sites, thedesorption of aniline and N -benzylideneaniline is promoted, which accelerates the spontaneous condensation coupling of aniline with benzaldehyde and inhibits the deep hydrogenation of N -benzylideneaniline. Consequently, an outstanding catalytic performance with high activity and selectivity in transfer hydrogenation coupling for imine synthesis has been realized. This work not only presents a highly efficient non-precious metal catalyst for functionalized imines production, but also illustrates the critical effect of electron structure of metallic active site on catalytic properties and opens a new avenue for fabricating diverse single-atom catalysts for selective hydrogenation reactions.
研究领域:
化学
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材料科学
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催化反应
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PAPERS
·
2023
·Vol. 77
·期 6
·3495-3500
·
IF 2.2
Shi Shaolin,Lan Huanshi,Tao Chenfa,Zhang Ying,Zhang Hao,Sun Qingdi,Zhang Xingcong,Guo Guanghui,He Qian,He Xiaohui,Ji Hongbing
Metal-free catalyst in imine synthesis was a great challenge due to the continuous rise in metal prices and unfriendly massive mining of metal. Herein, sp 2 /sp 3 hybridization nanodiamond–graphene (ND@G) was obtained by simple heat treatment of the commercially nanodiamonds (ND) under argon atmosphere, the as-prepared catalyst showed excellent activity and selectivity for directly imine synthesis. The physical structure changes of nanodiamond before and after heat treatment were well-characterization, and it was found that the nanodiamond surface layer changed from disordered sp 3 hybridized carbon to sp 2 /sp 3 core–shell structure. This study demonstrates the possibility of using metal-free catalysts for imine synthesis by nanodiamond.
研究领域:
催化化学
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材料科学
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有机合成
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 9
·4464-4471
·
IF 3.591
Bo Li,Yanxin Wang,Quan Chi,Ziliang Yuan,Bing Liu,Zehui Zhang
The selective synthesis of imines from biomass-derived chemicals over heterogeneous non-noble metal catalysts is of great importance for organic transformation. Herein, non-noble heterogeneous nitrogen-doped carbon supported Ni catalysts (abbreviated as Ni/CN–MgO-T, where T represents the pyrolysis temperature) have been facilely prepared from the simple pyrolysis of Ni precursors and biomass, and Ni/CN–MgO-600 with the smallest size of Ni nanoparticles demonstrated the highest catalytic activity. The reductive coupling of nitroarenes and carbonyl compounds could be performed under mild conditions (80 °C, and 10 bar H2), affording structurally-diverse imines with high to excellent yields (84.2–98.1%). Thanks to the mild reaction conditions, the developed method showed good tolerance to other functional groups such as nitriles, halogen and vinyl groups.
研究领域:
有机化学
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催化化学
✓ 已验证
DOI
高影响因子
Molecular Catalysis
·
2023
·
IF 4.6
Shipeng Wu,Rong Shang,Hao Zhang,Qinghu Tang,Qiue Cao,Bang Gu,Wenhao Fang
Low-temperature imine formation through oxidative coupling of alcohols with amines under base-free conditions is very important for fine-chemical synthesis. Supported-Au catalysts show superior performances toward selective oxidation reactions but are scarcely reported for the above application. In this work, the finely-dispersed Au nanoparticles (ca. 2.4 nm) loaded on magnetic Fe x Co 1 O y oxides were developed as novel, efficient and reusable heterogeneous catalyst. Varying the Fe/Co molar ratio allowed tuning the Au−Fe x Co 1 O y interface and further boosting the selective oxidation performance of Au. The optimum Au/Fe 0.25 Co 1 O y catalyst showed >99% yield of benzylideneaniline and 20.1 mol imine mol Au −1 h −1 productivity using the model reaction at 30 °C under air atmosphere without alkaline additives. This was the best result compared to benchmark Au-based catalysts in the literature. In addition, this catalyst exhibited superior performances towards gram-scaled synthesis and diverse substrates. XRD, N 2 -physisorption, TEM, H 2 -TPR, O 2 -TPD, EPR, pyridine-adsorbed FT-IR, and kinetic investigations were used to study this Au catalytic system. It was found that the synergy between Fe 2 O 3 and Co 3 O 4 can induce formation of abundantly mobile and reactive oxygen species (i.e., O 2 − and O − related to oxygen vacancies) and electron-rich metallic Au species on the surface of mesoporous Fe x Co 1 O y oxides. These interfacial features were disclosed to be vital to activating molecular O 2 and O H bond in an alcohol. Besides, it was demonstrated that the surface Lewis acidic sites associated with coordinatively unsaturated Co 3+ ions can help facilitate the tandem oxidation-condensation reactions.
研究领域:
催化化学
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材料科学
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有机合成
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2020
·Vol. 12
·期 23
·5948-5958
·
IF 4.853
Wanbing Gong,Miaomiao Han,Chun Chen,Yue Lin,Guozhong Wang,Haimin Zhang,Huijun Zhao
Graphical Nanocatalyst for organic synthesis : A simple and highly efficient CoPt alloy decorated Co nanoparticles catalyst was synthesized and showed excellent catalytic performance for the one-pot reductive amination with nitro compounds and aldehydes under mild reaction conditions. Developing high-performance heterogeneous catalysts for one-pot reductive amination reactions is critically important for pharmaceutical and agrochemical synthetic industries. In this work, N-doped carbon nanotubes supported CoPt alloy decorated Co nanoparticles (NPs) are successfully fabricated. As a consequence, the resultant catalyst exhibits desirable activity, selectivity and stability toward the one-pot synthesis of imines. More importantly, the extensive experimental studies and density function theory (DFT) calculations results reveal that the high catalytic activity of the catalyst is mainly due to the co-existence of CoPt alloy NPs and Co NPs with Co−N x active sites. The high selectivity of imines could be ascribed to the following aspects: (1) competitively preferred adsorption of nitroarenes to avoid side-hydrogenation of aldehydes; (2) weakened adsorption of imines to minimize its over-hydrogenation. This work may provide a promising direction and strategy to design high-performance reductive amination catalysts for industrial applications.
研究领域:
催化化学
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材料科学
·
有机合成
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2020
·Vol. 11
·期 3
·810-822
·
IF 5.721
Shipeng Wu,Hao Zhang,Qiue Cao,Qihua Zhao,Wenhao Fang
Direct oxidative coupling of alcohols with amines using a non-precious metal oxide catalyst under mild conditions is highly desirable for imine synthesis. In this work, a mesoporous Mn1ZrxOy solid solution catalyst prepared by a co-precipitation method showed excellent catalytic performance in imine synthesis from primary alcohols and amines without base additives in an air atmosphere. XRD, N2 physisorption, H2-TPR, O2-TPD, EPR and XPS were comprehensively used to unravel its structural, redox and amphoteric properties that closely depended on the interaction between MnOy and ZrO2 with a variable Zr ratio. The Mn1Zr0.5Oy catalyst presented the highest fractions of Mn3+ ions and reactive oxygen species on the surface, and the highest concentrations of acidic–basic sites, which were disclosed to play important roles in activating alcohols and molecular O2 in the rate-determining step. In the model reaction of oxidative coupling of benzyl alcohol with aniline, such enhanced features of the Mn1Zr0.5Oy catalyst can promote the intrinsic catalytic activity (iTOF of 1.87 h−1) and boost benzylideneaniline formation (5.56 mmol gcat.−1 h−1) based on a >99% yield at 80 °C respectively at a fast response. It can also work effectively at a room temperature of 30 °C, as well as for the gram-grade synthesis. This is one of the best results among all the MnOy-based catalysts in the literature. Moreover, this catalyst showed good stability and a wide substrate scope with good to excellent yields of imines.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2018
·Vol. 9
·期 2
·286-301
·
IF 5.365
Mengyuan Zhang,Shipeng Wu,Longchun Bian,Qiue Cao,Wenhao Fang
Ce–Ni mixed oxides with different Ni/Ce molar ratios, promoted by a rather low amount of Pd (0.2 wt%), were prepared by a simple one-pot precipitation method. The thus-synthesized CeNiXOY and Pd–CeNiXOY catalysts were applied respectively to the direct N-alkylation of amine and alcohol via oxidative coupling, under O2 in the absence of basic additives. The CeNiXOY catalyst could provide a >99% yield of imine in the model alkylation reaction of aniline with benzyl alcohol at 100 °C. The Pd-promoted Pd–CeNiXOY catalyst surprisingly showed an enhanced imine yield (>99%) at a mild temperature of 60 °C. This catalyst exhibited good reusability, and moreover, demonstrated high performance towards imine synthesis from various amines with alcohols. The presence of Pd species and the Ni/Ce molar ratio showed a synergistic impact on the conversion of aniline, as well as on the product selectivity, which was believed to be related to the improvement on the intrinsic activity of the oxidation of benzyl alcohol to benzaldehyde. Various physicochemical techniques, including ICP-MS, XRD, N2 adsorption–desorption, UV-Raman, H2-TPR, TEM, EPMA and XPS, were employed to study mainly the composition, structure and redox properties of the catalysts. The proportion of Ce3+ species and oxygen vacancies, which can be manipulated by the Ce–Ni redox system and the interaction between Ce and Ni, was crucial to the selective activation of alcohols in the presence of reactive amines. The activation of alcohol on the highly reactive Pd0 species was the other crucial factor.
研究领域:
催化化学
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材料科学
·
绿色化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）