SYNTHESIS-STUTTGART
·
2019
·Vol. 51
·期 21
·4048-4065
·
IF 2.867
Rui-Xiang Wang,Zhuang Fang,Guanyinsheng Qiu,Wenlin Xie,Jin-Biao Liu
The copper-catalyzed synthesis of 3-vinylisocoumarin-1-imine is reported. The transformation proceeds smoothly with good yields in THF and the regioselectivity was determined by a O-nucleophilic 6-endo cyclization. Studies on the mechanism indicate that copper trifluoroacetate serves as a Lewis acid, and the use of vinyl-connected 2-alkynylbenzamide is important for this O-nucleophilic 6-endo cyclization.
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高影响因子
ORGANOMETALLICS
·
2016
·
IF 4.186
Wenlong Luo,Antai Li,Shaofeng Liu,Hongqi Ye,Zhibo Li
A series of chromium(III) complexes, LCrCl3 (Cr1–Cr4: L = 2-(N-R2-benzimidazol-2-yl)-6-(3,5-R1-pyrazol-1-yl)pyridine; Cr1: R1 = H, R2 = H; Cr2: R1 = Me, R2 = H; Cr3: R1 = Me, R2 = Me; Cr4: R1 = Me, R2 = Bn), were synthesized and characterized by IR spectroscopy and elemental analysis. The studies of the solid state of Cr2 and Cr3 revealed distorted octahedral geometries around the chromium centers by X-ray diffractions. In the presence of MAO, Cr1–Cr4 exhibited high activities toward ethylene oligomerization (up to 2.17 × 106 g·mol–1(Cr)·h–1) and ethylene polymerization (up to 6.78 × 105 g·mol–1(Cr)·h–1). The oligomers were produced with high selectivity for α-olefins (>99%), confirmed by FT-IR and 13C NMR, and the distributions followed the Schulz–Flory equation. Various reaction parameters including the amount of cocatalyst, reaction temperature, and time were evaluated in detail, and it was evident that the title complexes had good thermal stability and the substituents on imidazole-N of the ligands dramatically impacted the catalytic activities as well as the distribution of the products.
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ChemistrySelect
·
2023
·Vol. 8
·期 40
·e202303078
·
IF 2.1
Yixin Tong,E. Mi,Li Zhou,Xiabin Wang,Biao Xiong
Graphical The synthesis of 2-acylindoles from sulfoxonium ylides with o-aminoaryl aldehydes via iridium-catalyzed N−H insertion and intramolecular condensation has been demonstrated. 2-Acylindoles possess widespread applications in functional chemicals. However, the convenient and selective synthesis of such important substructures has to date remained a challenge. Herein, a method to achieve 2-acylindoles from sulfoxonium ylides with o-aminoaryl aldehydes catalysed by Iridium has been developed with the merits of broad substrate scope, good functional tolerance, high efficiency and operational simplicity, which provides an alternative way to access functionalized indoles.
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CRYSTENGCOMM
·
2023
·Vol. 25
·期 36
·5085-5091
·
IF 3.1
Zhi-Yuan Yue,Rong-Meng Liao,Wang Luo,Na Wang,Le-Ping Miao,Heng-Yun Ye,Chao Shi
Organic–inorganic hybrid molecular ferroelectrics have attracted broad attention in the field of research of ferroelectric materials. Following the surge of stable candidates, hybrid bimetal molecular-based materials have been recently explored to achieve excellent ferroelectricity. However, rare hybrid bimetal molecular ferroelectrics were reported. Inspired by “ferroelectrochemistry”, a chiral nitrite-based hybrid bimetal molecular ferroelectric material, [(R)-3-quinuclidinol]2[LiCo(NO2)6] (1), was reported. The ferroelectric-paraelectric phase transition (C2 ↔ P321) behaviour of 1; was found at 343 K (Curie temperature, Tc) with a spontaneous electronic polarization (Ps) of 0.52 μC cm−2 and a coercive field (Ec) of 48 kV cm−1 at 298 K. Various-temperature single crystal structural analysis and dielectric constant measurements reveal that the rapid rotation of the organic cation and slight order–disorder transition of the NO2− anion are the origin of the ferroelectricity. To our knowledge, 1 is the first example of a nitrite-based hybrid bimetal molecular ferroelectric material that is triggered by an external electric field. This finding establishes a clear stimulus–structure–response relationship in advanced hybrid ferroelectric materials.
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Journal of the American Chemical Society
·
2017
·
IF 13.858
Yuyang Zhang,Yi Zou,Nelson L. Brock,Tingting Huang,Yingxia Lan,Xiaozheng Wang,Zixin Deng,Yi Tang,Shuangjun Lin
3-Substituted 2-oxindoles are important structural motifs found in many biologically active natural products and pharmaceutical lead compounds. Here, we report an enzymatic formation of the 3-substituted 2-oxindoles catalyzed by MarE in the maremycin biosynthetic pathway in Streptomyces sp. B9173. MarE is a homologue of FeII/heme-dependent tryptophan 2,3-dioxygenases (TDOs). Typical TDOs usually catalyze the insertion of two oxygen atoms from O2 into an indole ring to generate N-formylkynurenine (NFK)-like products. In contrast, MarE catalyzes the insertion of a single oxygen atom from O2 into an indole ring, to probably generate an epoxyindole intermediate that undergoes an unprecedented 2,3-hydride migration to form 2-oxindole structure. MarE shows substrate robustness to catalyze the conversion of a series of 3-substituted indoles into their corresponding 3-substituted 2-oxindoles. Although containing most key amino acid residues conserved in well-known TDO homologues, MarE falls into a separate new subgroup in the phylogenetic tree. The characterization of MarE and its homologue enriches the functional diversities of TDO superfamily and provides a new strategy for discovering novel natural products containing 3-substituted 2-oxindole pharmacophores by genome mining.
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PubMed
高影响因子
Desalination and Water Treatment
·
2014
·
IF 0.987
Ling Li,Jun Cheng Li,Zhuang Rao,Gong Wu Song,Bin Hu
The adsorpion of methylene blue from aqueous solution on a highly porous metal-organic framework material [Cu3(BTC)2(H2O)3] was studied in conjunction with the adsorption isotherm, kinetics and regenerate of the sorbent. The adsorption isotherms of methylene blue on [Cu3(BTC)2(H2O)3] followed both the Freundlich isotherm and the Langmuir adsorption isotherm. Adsorption kinetics was determined from the experimental data, and the results showed that the adsorption obeyed a pseudo-second-order kinetics. The best oscillate time and the best [Cu3(BTC)2(H2O)3] amount were discussed, and [Cu3(BTC)2(H2O)3] gave high adsorption in only 5 minutes. The used [Cu3(BTC)2(H2O)3] could be regenerated by glycol solution, thus recycled. SEM image and FT-TR spectra of recycled [Cu3(BTC)2(H2O)3] after different adsorption times were compared. The high adsorption capacity and excellent reusability make [Cu3(BTC)2(H2O)3] attractive for the removal of methylene blue from aqueous solution.
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Nature Communications
·
2020
·Vol. 11
·期 1
·1-12
·
IF 12.121
Hu Yechen,Jiang Bo,Weng Yejing,Sui Zhigang,Zhao Baofeng,Chen Yuanbo,Liu Lukuan,Wu Qiong,Liang Zhen,Zhang Lihua,Zhang Yukui
Protein N-phosphorylation plays a critical role in central metabolism and two/multicomponent signaling of prokaryotes. However, the current enrichment methods for O-phosphopeptides are not preferred for N-phosphopeptides due to the intrinsic lability of P-N bond under acidic conditions. Therefore, the effective N-phosphoproteome analysis remains challenging. Herein, bis(zinc(II)-dipicolylamine)-functionalized sub-2 μm core-shell silica microspheres (SiO 2 @DpaZn) are tailored for rapid and effective N-phosphopeptides enrichment. Due to the coordination of phosphate groups to Zn(II), N-phosphopeptides can be effectively captured under neutral conditions. Moreover, the method is successfully applied to an E.coli and HeLa N-phosphoproteome study. These results further broaden the range of methods for the discovery of N-phosphoproteins with significant biological functions.
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PubMed
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ACS Applied Nano Materials
·
2022
·
IF 6.14
Le Zhang,Xin Zhou,Shaohua Chai,Jian Guan,Guijun Fan,Wuxinchen Yang,Guojun Ma,Ning Han,Yunfa Chen
There is a high demand to synthesize ozone decomposition catalysts especially in high-space-velocity and high-relative-humidity (RH) environments. Herein, two polymorphs of cobalt hydroxide, α- and β-Co(OH)2, are synthesized and applied for ozone elimination. β-Co(OH)2 shows ∼90% ozone decomposition efficiency under high space velocity (weight hourly space velocity (WHSV) = 1,200,000 mL g–1 h–1, 25 °C, 40 ppm), which is far higher than that of α-Co(OH)2 (∼5%). β-Co(OH)2 has high spin Co(II) in distorted octahedral coordination caused by the Jahn-Teller effect, leading to a higher crystal field splitting energy level and thus contributing to the easier electron transfer between the ozone and catalyst. Moreover, β-Co(OH)2 still shows high performance (∼87%) even in humid conditions (RH ∼50%, 25 °C, 40 ppm, WHSV = 600,000 mL g–1 h–1), which is attributable to its abundant surface non-hydrogen-bonded hydroxyls weakening water molecule adsorption, providing an idea to develop highly efficient catalysts for ozone decomposition in humid environments.
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ANALYTICAL CHEMISTRY
·
2021
·
IF 6.986
Liu Shi,Lin Wang,Xuemei Ma,Xiaona Fang,Liangliang Xiang,Yongxiang Yi,Jinlong Li,Zhaofeng Luo,Genxi Li
With the outbreak of COVID-19, which is fast transmitting and highly contagious, the development of rapid, highly specific, and sensitive detection kits has become a research hotspot. The existing assay methods for SARS-CoV-2 are mainly based on enzymatic reactions, which require expensive reagents, hindering popular use, especially in resource-constrained areas. Herein, we propose an aptamer-based method for the assay of SARS-CoV-2 via binding of the spike protein using functionalized biomimetic nanochannels. To get the analogous effect of human ACE2, a receptor for the spike protein, the aptamer to bind to the spike S1 protein has been first screened by a SELEX technique and then immobilized on the previously prepared nanochannels. In the presence of SARS-CoV-2, the changes in steric hindrance and charge density on the surface of the nanochannels will affect the ion transport, along with a rapid electrochemical response. Our method has been successfully applied to detect the viral particles in clinical pharyngeal swab specimens in one step without sample treatment. We expect this rapid, reagent-free, and sensitive assay method to be developed as a useful tool for diagnosing COVID-19.
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PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2022
·Vol. 23
·期 10
·5715
·
IF 6.208
He Wang,Jingjing Li,Qian Yang,Lan Wang,Jing Wang,Yaxin Zhang,Yanjing Guo,Rui Li,Ruiqi Zhang,Xiaorong Tao,Bernal E. Valverde,Sheng Qiang,Hazem M. Kalaji,Shiguo Chen
2-Amino-3-methylhexanoic acid (AMHA) was synthetized as a non-natural amino acid more than 70 years ago; however, its possible function as an inducer of plant resistance has not been reported. Plant resistance inducers, also known as plant elicitors, are becoming a novel and important development direction in crop protection and pest management. We found that free AMHA accumulated in the mycelia but not in fermentation broths of four fungal species,Magnaporthe oryzaeand threeAlternariaspp. We unequivocally confirmed that AMHA is a naturally occurring endogenous (2S, 3S)-α-amino acid, based on isolation, purification and structural analyses. Further experiments demonstrated that AMHA has potent activity-enhancing resistance against extreme temperature stresses in several plant species. It is also highly active against fungal, bacterial and viral diseases by inducing plant resistance. AMHA pretreatment strongly protected wheat against powdery mildew,ArabidopsisagainstPseudomonas syringaeDC3000 and tobacco againstTomato spotted wilt virus. AMHA exhibits a great potential to become a unique natural elicitor protecting plants against biotic and abiotic stresses.Keywords:agricultural production;natural product;plant resistance inducer;biopesticide;biotic and abiotic stress
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PubMed
高影响因子
CELLULOSE
·
2018
·Vol. 25
·期 7
·3843-3851
·
IF 3.809
Hu Hui-Chao,Zhang Yu,Zeng Tong,Zhou Weining,Chen Lihui,Huang Liulian,Ni Yonghao
This paper reports a robust method for rapid determination of cellulose derived 5-hydroxymethyl-2-furfural (5-HMF) in biomass hydrolysate suspension based on headspace gas chromatography (HS-GC). The headspace equilibration at 150 °C for longer than 4 min with a pH range of 2.0–3.5 and a 50% (v/v) of ethanol content can obtain the full evaporation of 5-HMF, and eliminate the formation of additional 5-HMF generation from hexose. The linear GC response of 5-HMF was achieved by controlling the sample size within 20 μL. The results showed that this method has a good precision (relative standard deviation < 6.97%) and accuracy (recoveries ranged from 94.0 to 104.8%). The limit of quantification of the method was 51 mg/L. It was also found that a considerable amount of furfural (13.8%) and 5-HMF (18.7%) was adsorbed on condensed lignin and humins in residual biomass, and the washing procedure with ethanol can completely extract the adsorbed furfural and 5-HMF. The present method is accurate, simple, and robust, it will be a powerful tool for determining the content of 5-HMF in the liquid samples from biorefinery related processes.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2017
·
IF 2.323
Gaoyin He,Liping Wang,Midong Shi,Qingsong Li,Yunfang Wang
This work reveals experimental liquid–liquid equilibria (LLE) for ternary systems of (2-methoxyethanol + water + solvents) with methyl tert-butyl ether, ethyl acetate, and trichloromethane at 313.15 K and dichloromethane as solvent at 298.15 K under 101 kPa. The extraction capacity of the aforementioned solvents has been tested when it comes to the distribution ratio and separation factor according to the experimental data. The calculation results demonstrate that trichloromethane is an available solvent for extraction applications. Simultaneously, the reliability of the experimental LLE data was checked by Othmer–Tobias and Hand correlations, and all of the linear correlation coefficients were greater than 0.98. The experimental LLE values were regressed to obtain binary interaction parameters with both NRTL and UNIQUAC activity coefficient models. Both models shows satisfactory agreement with all of the root-mean square deviation values below 0.50.
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危险品化学品经营许可证（带存储）