CHEMICAL PAPERS
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2018
·Vol. 72
·期 6
·1339-1345
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IF 0.963
Li Bin,Chen Dan,Zhang Xiaoli,Dong Wenbo,Zhao Binxia
A catalyst comprised of 4-dimethylaminopyridine (DMAP) functionalized silica gel (SG-DMAP) was prepared via a convenient N-alkylation of 4-methylaminopyridine (MAP) with γ-chloropropylated silica gel promoted by potassium iodide. FT-IR, TG, SEM results illustrated that the DMAP was successfully immobilized on silica gel and the BET result suggested the pore structure was not altered after immobilization process. The highest immobilization amount of 0.75 mmol/g was obtained at 130 °C for 12 h. Activity test demonstrated that silica gel immobilized DMAP could be serve as a heterogeneous catalyst for the acylation with significant activity and stability.
研究领域:
有机化学
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催化材料
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DOI
高影响因子
FOOD CHEMISTRY
·
2015
·
IF 3.391
Shan Hong,Songbai Liu
The reactivity profile of all the hydroxyl groups in (+)-catechin towards acylation and their respective contribution to radical scavenging activity were systematically explored in this work. Selective acylation of the hydroxyls on different rings was carried out employing either a basic or acidic activation strategy. Monoacylation of B ring was achieved effectively with the aid of dimethyltin dichloride. Monoacylation of A ring was accomplished by sequential protection and deprotection of B and C rings. Based on specific acylation of all the individual hydroxyls of (+)-catechins, the structure radical scavenging activity relationship of each hydroxyl of (+)-catechin was established. It was demonstrated that the vicinal phenolic hydroxyls on B ring played the most important role in the ABTS radical scavenging activity and those on A and C rings made a much smaller contribution. This study has laid solid groundwork for further modification of the catechins and improvement of their properties.
研究领域:
植物化学
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天然产物化学
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药物化学
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DOI
PubMed
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
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2019
·Vol. 36
·期 5
·729-739
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IF 2.476
Pan Jiaying,Ou Zhimin,Tang Lan,Shi Hanbing
Racemic 1-phenylethylamine was resolved by enantiomer selective acetylation using Fe 3 O 4 -chitosan microsphere (CTS)-glutaraldehyde-lipase in a solvent-free system under an alternating magnetic field. Magnetic chitosan microspheres (Fe 3 O 4 -CTS) were prepared via chemical co-precipitation and cross-linked with lipase using glutaraldehyde to form Fe 3 O 4 -CTS-glutaraldehyde-lipase particles. The magnetic, physicochemical, and textural characteristics of Fe 3 O 4 -CTS-glutaraldehyde-lipase particles were assessed by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The optimal immobilization conditions were 2.4 mg/mL lipase, 10 mg/mL Fe 3 O 4 -CTS-glutaraldehyde, pH 8.5, 35 °C, 3 h. The loading amount of lipase and the specific activity got to 132 mg/g carrier and 48 U/g. The optimal reaction conditions of the acylation reaction using Fe 3 O 4 -CTS-glutaraldehyde-lipase were 300 mmol/L 1-phenylethylamine, 150 mg immobilized lipase, 2 mL vinyl acetate, 12.6 ×g rotating speed, 40 °C, 8 h. The activity of the Fe 3 O 4 -CTS-glutaraldehyde-lipase particles and conversion were improved when they were exposed to an external alternating magnetic field. The optimum magnetic field was 12 Gs (500 Hz). The conversion, enantiomeric excess of ( R )- N -(1-phenylethyl)acetamide, and E value reached 41.8%, 98.4%, and 264, respectively. Fe 3 O 4 -CTS-glutaraldehyde-lipase could be reused seven times. A kinetic model of the immobilized lipase-catalyzed resolution of 1-phenylethylamine was set up based on the ping-pong bi-bi mechanism. The kinetic constants were V max =1.62×10 −2 mM/min, K A =2.84×10 −4 mM, and K B =5.8×10 −1 mM. The model data fit well with the experimental data.
研究领域:
生物化学
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材料科学
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催化工程
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Qilin Xu,Jun Chen,Zihao Wang,Yongjun Zang,Guosi Li,Fucheng Zhu,Dong Liu,Chaoyue Sun
Olaparib is a top-selling pharmaceutical approved for the treatment of ovarian cancer. Herein, a two-step cascaded flow process was developed to synthesize Olaparib in microreactor. Since two different acyl groups are in the piperazine ring of Olaparib, a highly selective monoacylation route of piperazine is crucial for the efficient synthesis of Olaparib. For the first step (i.e., the monoacylation of piperazine), N , N' -carbonyldiimidazole was screened as coupling reagent due to its excellent selectivity , safety and greenness, a high monoacylation yield of 83 % was obtained in the microreactor. To understand the selective monoacylation reaction more deeply, the intrinsic kinetics was investigated based on mechanism cognition and experimental data. The established kinetic model was in good agreement with the experimental results in validation experiments. To further realize continuous manufacturing, the following step (i.e., amidation) was cascaded with the monoacylation in a microreactor system, Olaparib was continuously synthesized in the two-step cascaded microreactor with an overall yield of 78 % within 25 min. Relative to existing processes, the reaction steps were reduced, the economy and efficiency were remarkably improved, indicating efficient process intensification.
研究领域:
药物化学
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合成化学
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生物医学工程
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DOI
高影响因子
NORDIC PULP & PAPER RESEARCH JOURNAL
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2023
·Vol. 38
·期 3
·449-457
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IF 1.2
Chen Gong,Shujie Fan,Bin Yang,Yu Zhang,Jianping Ni,Zhenhua Su
The aim of this study was to investigate an effective approach for improving the dissolving pulp properties for making specialty fiber. The caustic and enzymatic treatment of the properties of dissolving pulp was conducted by analyzing the macromolecular structure and chemical composition. The results showed that the enzymatic treatment was more effective on influencing the macromolecular properties, while the caustic treatment had more influence on structural changing, mainly cellulose crystal structure and crystallinity. Meanwhile, to maintain a higher purity and higher brightness, caustic treatment would be beneficial in comparison with enzymatic treatment. The performance of caustic treated sample was evaluated in regarding to chemical composition and acetylation reaction performance, using commercial pulp as reference. The competitive feature of treated sample suggested its potential in future application.
研究领域:
制浆造纸工程
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生物化学
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DOI
高影响因子
ChemSusChem
·
2015
·Vol. 8
·期 12
·2066-2072
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IF 7.657
Yehong Wang,Jian Zhang,Jing Liu,Chaofeng Zhang,Zhixin Zhang,Jie Xu,Shutao Xu,Fangjun Wang,Feng Wang
Graphical CO 2 -mediated reactions: CO 2 -mediated metathesis reactions between amines and DMF to synthesize formamides are described. The N -formylation of amines to formamides is achieved by activating amines, not DMF, via a C N and N H bond metathesis reaction. Using this method, primary, secondary, aromatic, and heterocyclic amines as well as diamines can be obtained with good to excellent formamide yields. Herein, we report CO 2 -mediated metathesis reactions between amines and DMF to synthesize formamides. More than 20 amines, including primary, secondary, aromatic, and heterocyclic amines, diamines, and amino acids, are converted to the corresponding formamides with good-to-excellent conversions and selectivities under mild conditions. This strategy employs CO 2 as a mediator to activate the amine under metal-free conditions. The experimental data and in situ NMR and attenuated total reflectance IR spectroscopy measurements support the formation of the N -carbamic acid as an intermediate through the weak acid–base interaction between CO 2 and the amine. The metathesis reaction is driven by the formation of a stable carbamate, and a reaction mechanism is proposed.
研究领域:
有机化学
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绿色化学
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DOI
PubMed
高影响因子
Polymers
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2021
·Vol. 13
·期 20
·3463
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IF 4.329
Juntao Yan,Jinhong Liu,Ya Sun,Guangsen Song,Deng Ding,Guozhi Fan,Bo Chai,Chunlei Wang,Linbing Sun
Rice straw-derived cellulose (RSC) with purity of 92 wt.% was successfully extracted from rice straw by a novel and facile strategy, which integrated the C2H5OH/H2O autocatalytic process, dilute alkali treatment and H2O2bleaching process. Influencing factors of the cellulose extraction were systematically examined, such as ethanol concentration, alkali concentration, H2O2bleaching process and so on; the optimal extraction conditions of cellulose was determined. A series of rice straw-derived cellulose acetate (RSCA) with different degree of substitution (DS) were prepared by the acetylation reaction; the effects of Ac2O/cellulose ratio, reaction temperature and reaction time on the acetylation reaction were investigated. Results of FTIR and XRD analysis demonstrated that highly purified RSC and RSCA were prepared comparing with the commercial cellulose and cellulose acetate. Solubility analysis of RSCA with different DS indicated as-prepared RSCA with DS of 2.82 possessed the best solubleness, which was suitable for electrospinning. Moreover, the flexible RSCA fibrous membrane was easily fabricated by a facile electrospinning method. Our proposed method provided a strategy for realizing the high-value utilization of waste rice straw resource, as prepared RSC and RSCA can be used as chemical raw material, and electrospun RSCA fibrous membrane has various applications in medical materials, food packaging, water purification and so on.
研究领域:
材料科学
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生物资源工程
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DOI
高影响因子
EUROPEAN FOOD RESEARCH AND TECHNOLOGY
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2014
·Vol. 239
·期 4
·661-667
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IF 1.387
Xu Jiang,Qian Junqing,Li Shangqian
The utilization of bamboo-leaf extracts is limited by their weak solubility in lipidic media. As such, this study established an effective and relatively cheap method for preparation of ester of isoorientin isolated from bamboo-leaf extracts. Acylation of isoorientin with palmitic acid was efficient in a system containing dried tert -amyl alcohol and molecular sieves, yielding from 22 to 90 % bioconversion with different conditions; in detail, several factors (the origin and the amount of the lipase, temperature and water content of the system) were investigated in depth with the effect on the performance of the acylation reaction in this paper. Thereafter high purity ester (95 %) was obtained following a two-step solvent purification procedure and a chromatographic separation. With 1 H and 13 C nuclear magnetic resonance spectroscopy analysis, single product was detected to be 6″- O -palmitate isoorientin ester. Introducing an acyl group into isoorientin significantly improved its lipophilicity yet slightly reduced their antioxidant activity.
研究领域:
植物化学
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食品科学
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生物化学
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DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
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2021
·
IF 3.171
Yu Xie,Guoming Huang,Weiguo Hu,Yujun Wang
Piperacillin is a polar organic substance, and can reduce the interfacial tension of oil and water when dissolved in water. In this study, changes in dichloromethane–water interfacial tensions and microdroplet sizes during piperacillin synthesis from an aqueous solution of ampicillin and dichloromethane solution of 4-ethyl-2,3-dioxo-1-piperazine carbonyl chloride (EDPC) were observed using a pendent drop technique and a coaxial ring tube system with embedded high-speed camera, respectively. It was found that the rapid N -acylation reaction caused the piperacillin at the interface to synthesize rapidly and diffuse out slowly, resulting in the interfacial tension decreased from 19.5 mN·m −1 to 7.2 mN·m −1 rapidly and then increased slowly as the concentrations of ampicillin and EDPC were 0.05 mol·L −1 and 0.1 mol·L −1 . Meanwhile, the increase in the concentration of EDPC increased the peak concentration of piperacillin at the interface, and the addition of ethyl acetate to the ampicillin solution promoted mass transfer and reduced the aggregation of piperacillin effectively. During synthesis, the interfacial tension decreased, leading to a change in droplet sizes in the micro-reaction system. The two-phase reaction was carried out in a coaxial ring tube, with ampicillin and EDPC solutions as continuous and dispersed phases, respectively. The reaction reduced the dripping flow area, and the addition of ethyl acetate to the ampicillin solution slightly affected the division of the flow pattern. Under the same flow conditions, the droplet sizes of the reaction group were smaller than those of the no reaction group. The experimental results demonstrated that the increase of the continuous phase, decrease in the dispersed phase flow rate, or increase in EDPC concentration making droplet sizes smaller, and the addition of ethyl acetate slightly affected droplet sizes. These findings are important for the design and optimization of piperacillin synthesis reactors.
研究领域:
化学工程
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制药工程
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产品关联
DOI
高影响因子
KEY ENGINEERING MATERIALS
·
2013
·
IF 0
Yun Xia Jiang,Hu Jin Zuo,Yong Jia Shen,Feng Ping Yi
The Friedel-Crafts acylation reaction between 5-cyanoindole and 4-chlorobutyryl chloride was conducted in ionic liquid 1-buty-3-methylimidazolium chloroaluminate ([bmiCl/AlCl3), the major product was 5-cyano-3-(4-chlorobuty) indole. The structure of the product was characterized by Mass and 1H NMR spectra. When the molar ratio of AlCl3 to [bmiCl in [bmiCl/AlCl3 is at 1:1 or less, no 5-cyano-3-(4-chlorobuty) indole could be obtained. The suitable molar ratios of AlCl3 to [bmiCl in [bmiCl/AlCl3 were from 2:1 to 3:1, the yields of the major product were from 68% to 70%, respectively. When the molar ratio of [bmiCl/AlCl3 to 5-cyanoindole was less than 2:1, the acylation reaction was difficult to carry out, because 5-cyanoindole would be not totally dissolve in [bmiCl/AlCl3 under the situation.
研究领域:
有机化学
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合成化学
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DOI
CHINESE JOURNAL OF CHEMISTRY
·
2020
·Vol. 38
·期 10
·1057-1064
·
IF 3.826
Chongyang Du,Yaofeng Chen
Summary of main observation and conclusion Transformation of CO 2 into valuable organic compounds catalysed by cheap and biocompatible metal catalysts is one of important topics of current organic synthesis and catalysis. Herein, we report the zinc powder catalysed formylation and urealation of amines with CO 2 and (EtO) 3 SiH under solvent free condition. Using 2 mol% zinc powder as the catalyst, a series of secondary amines, both the aromatic ones and the aliphatic ones, can be formylated into formamides. When primary aromatic amines were used as the substrates, the reactions produce urea derivatives. The electronic and steric effects from the substrates on the formylation and urealation reactions were observed and discussed. The recovery and reusability of zinc powder were investigated, showing the zinc powder can be reused in the formylation reaction without loss of catalytic activity. The analysis on the reactants/products mixture after filtering out the zinc powder showed the zinc concentration in the mixture is low to 1 ppm. The pathways for the formylation and urealation of amines with this catalytic system were also investigated, and related to the different substrates.
研究领域:
有机化学
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催化化学
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DOI
高影响因子
CARBOHYDRATE RESEARCH
·
2012
·
IF 2.332
Liqiang Wu,Zhikui Yin
A simple and clean synthesis of per- O -acetylation carbohydrate derivatives has been accomplished by treatment of sugars with a stoichiometric quantity of acetic anhydride under solvent-free conditions in the presence of sulfonic acid functionalized nano γ-Al 2 O 3 as an efficient and environmentally benign catalyst.
研究领域:
有机化学
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催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）