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Direct C-H Bond Activation of Benzoxazole and Benzothiazole with Aryl Bromides Catalyzed by Palladium（Ⅱ）-N-heterocyclic Carbene Complexes

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Chinese Journal of Chemistry 2018年第9期36卷 837-844页

作者： Murat Kaloglu Nazan Kaloglur ismail Ozdemir Department of Chemistry Faculty of Science and Arts inonu University 44280 Malatya Turkey catalysis research and Application center inonu University 44280Malatya Turkey

Herein, we report that a series of novel palladium（II）-NHC complexes （NHC=N-heterocyclic carbene） were synthesized. The structures of all novel complexes were characterized by ^1H NMR, ^13C NMR, FT-IR spectroscopy and elemental analysis techniques. These palladium（ll）-NHC complexes were tested as efficient catalysts in the direct C-H bond activation of benzoxazole and benzothiazole with aryl bromides in the presence of 1 mol% catalyst loading at 150 ℃ for 4 h. Under the given conditions, various aryl bromides were successfully applied as the arylating reagents to achieve the 2-arylbenzoxazoles and 2-arylbenzothiazoles in acceptable to high yields.

关键词： benzimidazolium bromide benzoazoles direct C-H bond activation N-heterocyclic carbene palladium

Tuning performance of Pd/Sn_(0.9)Ce_(0.1)O_2 catalyst for methane combustion by optimizing calcination temperature of support

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Rare Metals 2019年第2期38卷 107-114页

作者： Kai Shen Jia-Pan Lin Qian Xia Lu Dai Guo-Jun Zhou Yang-Long Guo Guan-Zhong Lu Wang-Cheng Zhan Technology center China Tobacco Zhejiang Industrial Co.Ltd. Key Laboratory for Advanced Materials and research Institute of Industrial catalysis East China University of Science and Technology

A series of 0.2 wt% Pd/Sn_(0.9)Ce_(0.1)O_2 catalysts were prepared by impregnation method based on the presynthesis of Sn_(0.9)Ce_(0.1)O_2 support prepared by co-precipitation method, and then characterized by Brunauer–Emmett–Teller(BET), X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), Raman, CO chemical adsorption and hydrogen temperature-programmed reduction(H_2-TPR) techniques. The effect of calcination temperature of the composite oxide support on the catalytic performances of the Pd/Sn_(0.9)Ce_(0.1)O_2 catalyst for the CH_4 total oxidation was studied. It is found that the catalytic activity of the Pd/Sn_(0.9)Ce_(0.1)O_2 catalyst increases with the increase in calcination temperature of the Pd/Sn_(0.9)Ce_(0.1)O_2 support. The 0.2 wt% Pd/Sn_(0.9)Ce_(0.1)O_2/1100 catalyst(the Pd/Sn_(0.9)Ce_(0.1)O_2 support was calcined at 1100 ℃) exhibits the best reactive activity(T_(10)= 255 ℃). The excellent activity of the 0.2 wt% Pd/Sn_(0.9)Ce_(0.1)O_2/1100 catalyst should be attributed to the high reducibility of PdO, the excellent oxygen mobility of the support and the high content of active Pd^(2+) species on the Pd/Sn_(0.9)Ce_(0.1)O_2 catalyst.

关键词： Catalytic combustion Methane PdO SnxCe1-xO2 Calcination temperature

Concise syntheses of 13-methylprotoberberine and 13-methyltetrahydroprotoberberine alkaloids

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Chinese Chemical Letters 2022年第12期33卷 5080-5083页

作者： Wenchang Chen Xiaofen Yi Hongmin Qu Yu Chen Pei Tang Fener Chen Sichuan research center for Drug Precision Industrial Technology West China School of PharmacySichuan UniversityChengdu 610041China Engineering center of catalysis and Synthesis for Chiral Molecules Department of ChemistryFudan UniversityShanghai 200433China hanghai Engineering center of Industrial Asymmetric catalysis for Chiral Drugs Shanghai 200433China

The concise syntheses of eight 13-methylprotoberberine(13-MePB)and eight enantioenriched 13-methyltetrahydroprotoberberine(13-MeTHPB)alkaloids have been achieved in a tactically modular *** synthetic work features a one-pot metal-free Pictet-Spengler/Friedel-Crafts hydroxyalkylation/dehydration/oxidation sequence and a following highly enantioselective Ir-catalyzed *** such brevity and modularity,our developed synthetic route would be greatly beneficial to the efficient syntheses of existing natural products and new fully synthetic variants of 13-MePB and 13-MeTHPB family.

关键词： 13-Methylprotoberberine 13-Methyltetrahydroprotoberberine One-pot metal-free sequence Asymmetric hydrogenation

Ti-Si composite oxide-supported cobalt catalysts for CO_2 hydrogenation

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Journal of Natural Gas Chemistry 2011年第5期20卷 558-564页

作者： Jakrapan Janlamool Piyasan Praserthdam Bunjerd Jongsomjit center of Excellence on catalysis and Catalytic Reaction Engineering Department of Chemical Engineering Faculty of Engineering Chulalongkorn University

In the present work, different silica-based supported cobalt （Co） catalysts were synthesized and used for CO2 hydrogenation for methanation. Different supports, such as SSP, MCM-41, TiSSP and TiMCM were used to prepare Co catalysts with 20 wt% Co loading. The supports and catalysts were characterized by means of N2 physisorption, XRD, SEM/EDX, XPS, TPR and CO chemisorption. It is found that after calcination of catalysts, Ti is present in the form of anatase. The introduction of Ti plays important roles in the properties of Co catalysts by：（i） facilitating the reduction of Co oxides species which are strongly interacted with support, （ii） preventing the formation of silicate compounds, and （iii） inhibiting the RWGS reaction. Based on CO2 hydrogenation, the CoTiMCM catalyst exhibites the highest activity and stability.

关键词： CO2 hydrogenation titania-silica cobalt catalysts methanation

Hierarchical porous hard carbon enables integral solid electrolyte interphase as robust anode for sodium-ion batteries

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Rare Metals 2020年第9期39卷 1053-1062页

作者： Xu-Kun Wang Juan Shi Li-Wei Mi Yun-Pu Zhai Ji-Yu Zhang Xiang-Ming Feng Zi-Jie Wu Wei-Hua Chen Green catalysis center College of ChemistryZhengzhou UniversityZhengzhou 450001China center of Advanced Materials research Zhongyuan University of TechnologyZhengzhou 450007China Northwest Composites center Department of MaterialsUniversity of ManchesterManchester M139PLUK

Hard carbon is the most promising anode for sodium-ion battery applications due to the wide availability and low work ***,it often delivers worse electrochemical performance in ester-based ***,a hierarchically porous loose sponge-like hard carbon with a highly disordered phase,prepared from the biomass of platanus bark,exhibits superior rate performance with a capacity of 165 mAh·g-1 at a high current of1 A·g-1,and high retention of 71.5%after 2000 cycles in an ester-based *** effect of the hierarchically porous loose sponge-like structure on the formation dynamics of solid electrolyte interphase(SEI),and related properties,was studied via cyclic voltammetry(CV),galvanostatic intermittent titration technique(GITT),X-ray photoelectron spectroscope(XPS),Fourier transform infrared spectroscopy(FTIR)and electrochemical impedance spectroscopy(EIS)*** results reveal that the hierarchically porous structure can construct continued connecting channels and accelerate the electrolyte transport,which is beneficial to the reaction kinetics of ***,the mesoporous structure is conducive to good contact between electrolyte and materials and shortens the Na+diffusion path,which in turn facilitates the charge transfer kinetics in the material.

关键词： Sodium-ion battery Hard carbon Hierarchically porous structure SEI Ester-based electrolyte

Structural isomer and high-yield of Pt1Ag28 nanoduster via one-pot chemical wet method

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Nano research 2019年第2期12卷 309-314页

作者： Xinzhang Lin Chao Liu Keju Sun Ren'an Wu Xuemei Fu Jiahui Huang gold catalysis research Centre State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China College of Environmental and Chemical Engineering Yanshan University Qinhuangdao 066004 China Laboratory of High-Resolution Mass Spectrometry Technologies Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian 116023 China University of Chinese Academy of Sciences Beijing 100049 China

In order to understand the structure-property correlation and explore the application of metal nanoclusters, it is important and intriguing to determine their crystal structure and obtain high-yield. At the same time, this is also a challenge in nanoscience and technology. Here, we report the highly efficient synthesis of Pt1Ag28 nanocluster via one-pot chemical wet method. The crystal structure of Pt1Ag28 nanocluster was determined by X-ray crystallography to be a face centered cubic (FCC) kernel. This novel structure is the structural isomerization of Pt1Ag28 nanocluster reported before. This phenomenon is first discovered in the synthesis of alloy nanoclusters. In addition, Pt1Ag28 nanocluster has high yield and exhibits potential optics in the near infrared (NIR) fluorescent imaging. The time-dependent density functional theory (TD-DFT) calculation implied that the optical property of Pt1Ag28 was sensitive to its structure. This work provides a simple method to synthesize alloy nanoclusters with structural isomerization.

关键词： Pt1Ag28 nanocluster one-pot synthesis structural isomerization high yield strong fluorescenee

Comment on“Assessing gully erosion and rehabilitation using multi temporal LiDAR DEMs:Case study from the Great Barrier Reef catchments,Australia”by Khan et al.,2023

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International Soil and Water Conservation research 2024年第2期12卷 481-486页

作者： James S.Daley Andrew P.Brooks John R.Spencer Coastal and Marine research Centre Griffith UniversityGold Coast4215Australia

Geomorphic change detection(GCD)using high resolution topographic data can provide important insights into geomorphological ***,considerations must first be given to the mechanisms and dynamics producing landscape change when considering an appropriate experimental *** et al.(2023)investigate gully erosion rates and processes in different untreated and rehabilitated gullies using multi-temporal aerial lidar survey(ALS)***,an inappropriate time interval between sampling,a lack of uncertainty measures and lack of baseline monitoring survey data lead them to arrive at incorrect *** data is presented from the same field sites,which demonstrate gully sediment losses have been underestimated by at least 330%and potentially over an order of magnitude.A number of critical shortcomiongs of the paper are *** time intervals between data collection have led to a lack of detection of some sediment transport *** associated with gully rehabilitation have been conflated with geomorphic change,as no post-construction baseline data was collected.A lack of post-construction baseline data for this analysis means ongoing erosion and deposition cannot be resolved in the rehabilitated gully *** these errors in approach,discussions of gully geomorphic processes,erosion mechanisms and evaluations of rehabilitation efforts are unsupported,overstated and *** has important implications for land management efforts and planning as well ongoing research on alluvial gully erosion,which is largely overlooked by Khan et al.(2023).

关键词： erosion stated discussions

Asymmetric synthesis of syn-aryl-(2S,3R)-2-chloro-3-hydroxy esters via an engineered ketoreductase-catalyzed dynamic reductive kinetic resolution

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Chinese Chemical Letters 2023年第9期34卷 156-159页

作者： Xiaoping Yue Yitong Li Di Sang Yuan Tao Zedu Huang Fener Chen Sichuan research center for Drug Precision Industrial Technology West China School of PharmacySichuan UniversityChengdu 610041China Engineering center of catalysis and Synthesis for Chiral Molecules Department of ChemistryFudan UniversityShanghai 200433China Shanghai Engineering center of Industrial Asymmetric catalysis for Chiral Drugs Shanghai 200433China

We report here a generic,green synthesis of 17 valuable syn-aryl-(2S,3R)-2–chloro-3–hydroxy esters(syn-(2S,3R)-1)in 73%-99%isolated yields along with 6.1:1–83:1 dr and 31%~>99%ee,through dynamic reductive kinetic resolution of racemic arylα–chloroβ-keto esters(2)catalyzed by an engineered ketoreductase which was obtained via ep PCR-based directed *** hectogram scale synthesis of syn-(2S,3R)-1b at a substrate concentration of 120 g/L showcased the application potential of the biocatalytic method developed presently.

关键词： (2S,3R)-2-Chloro-3-hydroxy esters Dynamic reductive kinetic resolution Ketoreductase Directed evolution Asymmetric synthesis

Synergistic Effects of the ZnCl_2-SiCl_4 Modified TiCl_4/MgCl_2/THF Catalytic System on Ethylene/1-Hexene and Ethylene/1-Octene Copolymerizations

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Chinese Journal of Polymer Science 2014年第1期32卷 84-91页

作者： Wanna Phiwkliang Bunjerd Jongsomjit Piyasan Praserthdam center of Excellence on catalysis and Catalytic Reaction Engineering Department of Chemical Engineering Faculty of Engineering Chulalongkorn University

The copolymerizations of ethylene with 1-hexene or 1-0ctene by using TiC14/MgCI2/THF catalysts modified with different metal halide additives （ZnCI2, SIC14, and the combined ZnC12-SiCl4） were investigated based on catalytic activity and copolymer properties. It was found that the catalyst modified with mixed ZnC12-SiC14 revealed the highest activities for both ethylene/1-hexene and ethylene/1-0ctene copolymerization. The increase in activities was due to the formation of acidic sites by modifying the catalysts with Lewis acids. Based on the FTIR measurements, the characteristic C--O--C peaks of the catalysts modified with metal halide additives were slightly shifted to lower wavenumber when compared to the unmodified catalyst. This showed that the modified catalysts could generate more acid sites in the TiC14/MgC12/THF catalytic system leading to an increase in activities as well as comonomer insertion （as proven by IaC-NMR）. However, Lewis acid- modifications did not affect the microstructure of the copolymers obtained. By comparison on the properties of copolymers prepared with the unmodified catalyst, it was found that polymers with ZnC12 and/or SIC14 modification exhibited a slight decrease in melting temperature, crystallinity and density. It is suggested that these results were obtained based on the different amount of ct-olefins insertion, regardless of the types of Lewis acids and comonomer.

关键词： Ziegler-Natta catalyst Lewis acid Copolymerization of ethylene with a-olefin SIC14 ZnC12.