95-64-7Relevant articles and documents
Subnanometer Bimetallic Platinum–Zinc Clusters in Zeolites for Propane Dehydrogenation
Cheng, Jun,Fan, Qiyuan,Jia, Ran,Jiang, Zheng,Li, Lin,Mayoral, Alvaro,Miao, Shu,Sun, Qiming,Terasaki, Osamu,Wang, Ning,Wang, Ye,Xu, Jun,Yang, Dong-Chun,Yang, Ruoou,Yu, Jihong,Zeng, Lei,Zhang, Jichao,Zhang, Peng,Zhang, Qinghong,Zhang, Tianjun,Zhou, Wei
, p. 19450 - 19459 (2020)
Propane dehydrogenation (PDH) has great potential to meet the increasing global demand for propylene, but the widely used Pt-based catalysts usually suffer from short-term stability and unsatisfactory propylene selectivity. Herein, we develop a ligand-protected direct hydrogen reduction method for encapsulating subnanometer bimetallic Pt–Zn clusters inside silicalite-1 (S-1) zeolite. The introduction of Zn species significantly improved the stability of the Pt clusters and gave a superhigh propylene selectivity of 99.3 % with a weight hourly space velocity (WHSV) of 3.6–54 h?1 and specific activity of propylene formation of 65.5 mol (Formula presented.) gPt?1 h?1 (WHSV=108 h?1) at 550 °C. Moreover, no obvious deactivation was observed over PtZn4?S-1-H catalyst even after 13000 min on stream (WHSV=3.6 h?1), affording an extremely low deactivation constant of 0.001 h?1, which is 200 times lower than that of the PtZn4/Al2O3 counterpart under the same conditions. We also show that the introduction of Cs+ ions into the zeolite can improve the regeneration stability of catalysts, and the catalytic activity kept unchanged after four continuous cycles.
Impregnating Subnanometer Metallic Nanocatalysts into Self-Pillared Zeolite Nanosheets
Wang, Ning,Sun, Qiming,Zhang, Tianjun,Mayoral, Alvaro,Li, Lin,Zhou, Xue,Xu, Jun,Zhang, Peng,Yu, Jihong
, p. 6905 - 6914 (2021)
Impregnation is the most commonly used approach to prepare supported metal catalysts in industry. However, this method suffers from the formation of large metal particles with uneven dispersion, poor thermal stability, and thus unsatisfied catalytic performance. Here, we demonstrate that the self-pillared MFI zeolite (silicalite-1 and ZSM-5) nanosheets with larger surface area and abundant Si-OH groups are ideal supports to immobilize ultrasmall monometallic (e.g., Rh and Ru) and various bimetallic clusters via simple incipient wetness impregnation method. The loaded subnanometric metal clusters are uniformly dispersed within sinusoidal five-membered rings of MFI and remain stable at high temperatures. The Rh/SP-S-1 is highly efficient in ammonia borane (AB) hydrolysis, showing a TOF value of 430 molH2 molRh-1 min-1 at 298 K, which is more than 6-fold improvement over that of nanosized zeolite-supported Rh catalyst and even comparable with that of zeolite-supported Rh single-atom catalyst. Because of the synergistic effect between bimetallic Rh-Ru clusters and zeolite acidity, the H2 generation rate from AB hydrolysis over Rh0.8Ru0.2/SP-ZSM-5-100 reaches up to 1006 molH2 molmetal-1 min-1 at 298 K, and also shows record activities in cascade hydrogenation of various nitroarenes by coupling with the hydrolysis of AB. This work demonstrates that zeolite nanosheets are excellent supports to anchor diverse ultrasmall metallic species via the simple impregnation method, and the obtained nanocatalysts can be applied in various industrially important catalytic reactions.
Industrial Cunninghamia lanceolata carbon supported FeO(OH) nanoparticles-catalyzed hydrogenation of nitroarenes
Fu, Lihua,Li, Dingzhong,Lu, Hao,Qiu, Renhua,Sun, Tulai,Xing, Chen,Yang, Tianbao
, (2022/01/11)
The development of green and efficient methods for hydrogenation of nitroarenes is still highly demanding in organic synthesis. Herein, we report an industrial Cunninghamia lanceolata carbon supported FeO(OH) nanoparticles process for the synthesis of aryl amines with good yields via hydrogenation of nitroarenes. Nine key anti-cancer drug intermediates were successfully achieved with protocol. And Osimertinib intermediate 4m can be smoothly synthesized at a 2.67 kg-scale with >99.5% HPLC purity. This protocol features cheap carbon source, highly catalytic activity, simple operation, kilogram-scalable and recyclable catalysts (eight times without observable losing activity).
C-H Amination of Arenes with Hydroxylamine
See, Yi Yang,Sanford, Melanie S.
supporting information, p. 2931 - 2934 (2020/04/09)
This Letter describes the development of a TiIII-mediated reaction for the C-H amination of arenes with hydroxylamine. This reaction is applied to a variety of electron-rich (hetero)arene substrates, including a series of natural products and pharmaceuticals. It offers the advantages of mild conditions (room temperature), fast reaction rates (30 min), compatibility with ambient moisture and air, scalability, and the use of inexpensive commercial reagents.
Direct conversion of phenols into primary anilines with hydrazine catalyzed by palladium
Qiu, Zihang,Lv, Leiyang,Li, Jianbin,Li, Chen-Chen,Li, Chao-Jun
, p. 4775 - 4781 (2019/05/16)
Primary anilines are essential building blocks to synthesize various pharmaceuticals, agrochemicals, pigments, electronic materials, and others. To date, the syntheses of primary anilines mostly rely on the reduction of nitroarenes or the transition-metal-catalyzed Ullmann, Buchwald-Hartwig and Chan-Lam cross-coupling reactions with ammonia, in which non-renewable petroleum-based chemicals are typically used as feedstocks via multiple step syntheses. A long-standing scientific challenge is to synthesize various primary anilines directly from renewable sources. Herein, we report a general method to directly convert a broad range of phenols into the corresponding primary anilines with the cheap and widely available hydrazine as both amine and hydride sources with simple Pd/C as the catalyst.
Method for continuous hydrogenation preparation of aromatic amine through nitro-compound
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Paragraph 0042-0043, (2019/06/27)
The invention provides a method for continuous hydrogenation preparation of aromatic amine through a nitro-compound, and belongs to the field of heterogeneous catalysis. The method comprises the stepsthat the nitro-compound serves as a raw material, nano-porous palladium serves as a catalyst and hydrogen serves as a hydrogen source; a static bed liquid phase catalysis hydrogenation process is utilized for synthesizing the nitro-compound into the aromatic amine, and the activity of the catalyst is not lowered after 400-hour continuous running of the catalyst; continuous hydrogenation is carried out under the catalysis condition of the nano-porous palladium catalyst to obtain an aromatic amine product. The method is mild in reaction condition, high in reaction selectivity, compatible in substrate and good in stability, and industrial production is facilitated.
Zeolite-Encaged Single-Atom Rhodium Catalysts: Highly-Efficient Hydrogen Generation and Shape-Selective Tandem Hydrogenation of Nitroarenes
Sun, Qiming,Wang, Ning,Zhang, Tianjun,Bai, Risheng,Mayoral, Alvaro,Zhang, Peng,Zhang, Qinghong,Terasaki, Osamu,Yu, Jihong
supporting information, p. 18570 - 18576 (2019/11/25)
Single-atom catalysts are emerging as a new frontier in heterogeneous catalysis because of their maximum atom utilization efficiency, but they usually suffer from inferior stability. Herein, we synthesized single-atom Rh catalysts embedded in MFI-type zeolites under hydrothermal conditions and subsequent ligand-protected direct H2 reduction. Cs-corrected scanning transmission electron microscopy and extended X-ray absorption analyses revealed that single Rh atoms were encapsulated within 5-membered rings and stabilized by zeolite framework oxygen atoms. The resultant catalysts exhibited excellent H2 generation rates from ammonia borane (AB) hydrolysis, up to 699 min?1 at 298 K, representing the top level among heterogeneous catalysts for AB hydrolysis. The catalysts also showed superior catalytic performance in shape-selective tandem hydrogenation of various nitroarenes by coupling with AB hydrolysis, giving >99 % yield of corresponding amine products.
Highly efficient reduction of nitro compounds: Recyclable Pd/C-catalyzed transfer hydrogenation with ammonium formate or hydrazine hydrate as hydrogen source
Chen, Xia,Zhou, Xiao-Yu,Wu, Hong,Lei, Yi-Zhu,Li, Jin-Hui
supporting information, p. 2475 - 2484 (2018/10/25)
Herein, we described a highly efficient heterogeneous Pd/C-catalyzed transfer hydrogenation of nitro compounds for the synthesis of primary amines, using ammonium formate and hydrazine hydrate as hydrogen source independently. The products were obtained with up to >99% yield. Furthermore, gram scale and recycling of catalyst had been tested with well results.
Multi-phase catalytic hydrogenation reduction method of unsaturated compound
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Paragraph 0050; 0051; 0052; 0053; 0054, (2019/04/26)
The invention discloses a multi-phase catalytic hydrogenation reduction method of an unsaturated compound. The method comprises a step of carrying out multi-phase catalytic hydrogenation reaction to reduce the unsaturated compound; the multi-phase catalytic hydrogenation reaction takes water as a solvent and a hydrophobic and atmophile material as a catalyst. According to the multi-phase catalytichydrogenation reduction method, hydrophobic and atmophile properties of the catalyst are utilized, so that hydrogen gas can be rapidly adsorbed and spread on the surface of the catalyst, the surfacehydrogen concentration of the catalyst is improved, and the hydrogenation reaction speed is improved; a conventional pressurizing method is changed, so that requirements on equipment and dangerousnessare reduced. The atmophile catalyst Pd/GA can be used for hydrogenation of double bonds, nitryl and an aldehyde group under normal pressure, and is applicable to wide types. The method provided by the invention has a wide application potential in other fields needing gas to react.
Development of a novel protocol for chemoselective deprotection of N/O-benzyloxycarbonyl (Cbz) at ambient temperature
Saroha, Mohit,Aggarwal, Komal,Bartwal, Gaurav,Khurana, Jitender M.
, p. 2231 - 2235 (2018/10/02)
Abstract: A novel protocol for the deprotection of N-benzyloxycarbonyl and O-benzyloxycarbonyl groups by nickel boride generated in situ from NaBH4 and NiCl2·6H2O in methanol at room temperature has been developed to give the corresponding amines and phenols. This protocol is chemoselective as groups like chloro, bromo, amide, ester, pyridine, and tert-butyloxycarbonyl moiety are unaffected under these conditions. The deprotection has also been validated in gram scale reactions, to establish the wider appropriateness of this protocol. Graphical abstract: [Figure not available: see fulltext.].
