摘要:
A simple and efficient visible-light-initiated cascade reaction of 2-isothiocyanatonaphthalenes and amines with ambient dioxygen as the sole oxidant under additive-, external photocatalyst-free and ambient conditions was developed. 38 Examples of N-substituted naphtho[2,1-d]thiazol-2-amines were regioselectively constructed in good to excellent yields.
摘要:
The design of Ni-rich core and Mn-rich shell is of great significance for improving the electrochemical performance of lithium-ion battery cathode materials at high voltage. The core-shell structure LiNi0.8Co0.1Mn0.1O2 (CS-NCM811) cathode materials is prepared through co-precipitation method. XRD shows that the cathode materials have alpha-NaFeO2 layered structure and SEM images show that the material has a good morphology. The elemental compositions in Ni, Co, and Mn of both the core and shell of the CS-NCM811 particles are analyzed by EDS. The electrochemical performance results show that the CS-NCM811 provides better cycling stability than the homogeneous. The capacity retention rate of CS-NCM811 at 3 C is significantly higher than that of homogeneous materials at 4.6 V. The change in morphology after 100 cycles proves that the core-shell structure can inhibit the side reaction and reduce polarization. In addition, the CS-NCM811 has better thermal stability with high exothermic temperature and low heat.
摘要:
An eco-friendly,sustainable and practical method for the efficient preparation of 5-organylselanyl uracils through the electrochemical selenylation of uracils and dio rganyl diselenides at room temperature under oxidant-and external electrolvte-free conditions was developed.
摘要:
As a primary building block for protein synthesis, L-arginine (L-Arg) is also a precursor for the synthesis of important metabolites, and is involved in various physiological and pathophysiological processes. L-Arg is a potential biomarker in clinical diagnosis and nutritional status assessment, making it valuable to quantify and monitor this biomolecule. In this study, peptide aptamers that specifically interact with L-Arg were identified by high-throughput molecular docking, and the binding capacities between the synthesized peptide aptamers and L-Arg were then measured by isothermal titration calorimetry. We hypothesized that the peptide aptamer with the greatest binding capacity could be used as the recognition element in a biosensor. A chemosynthetic peptide aptamer modified with mercaptan and spacer units (thioctic acid-GGGG-FGHIHEGY) was thus used to construct label-free electrochemical impedimetric biosensors for L-Arg based on gold electrodes. The optimum biosensor showed good sensitivity to L-Arg with a linear range of 0.1 pM-0.1 mM, and the calculated limit of detection (three times the signal-to-noise ratio) was 0.01 pM. Interference studies and assays of diluted serum samples were also carried out, and satisfactory results obtained. In conclusion, a potential method of peptide aptamer screening and biosensor fabrication for detecting small biological molecules was demonstrated. (C) 2020 Elsevier B.V. All rights reserved.
作者机构:
[肖忠良; 周乘风; 宋刘斌; 曹忠; 蒋鹏] Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation, School of Chemistry and Food Engineering, Changsha University of Science and Technology, Changsha;Hunan;410114, China;[肖忠良; 周乘风; 宋刘斌; 曹忠; 蒋鹏] Hunan;[肖忠良; 周乘风; 宋刘斌; 曹忠; 蒋鹏] 410114, China
作者机构:
[Du, Kui; Han, Xiao-Ran; Wu, Yan; Chen, Jin-Yang; Wu, Hong-Yu] Yangtze Normal Univ, Coll Chem & Chem Engn, Chongqing 408000, Peoples R China.;[Gui, Qing-Wen; He, Wei-Min; Cao, Zhong] Changsha Univ Sci & Technol, Hunan Prov Key Lab Mat Protect Elect Power & Tran, Changsha 410114, Peoples R China.;[Gui, Qing-Wen] Hunan Univ Sci & Technol, Sch Chem & Chem Engn, Xiangtan 411201, Peoples R China.;[Lin, Ying-Wu] Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.
通讯机构:
[He, Wei-Min] C;Changsha Univ Sci & Technol, Hunan Prov Key Lab Mat Protect Elect Power & Tran, Changsha 410114, Peoples R China.
摘要:
A catalyst-, oxidant-, electrolyte-free method for the preparation of alpha-ketoamides through the direct electrochemical amidation of alpha-ketoaldehydes and amines with innocuous hydrogen as the sole byproduct at ambient temperature was developed. The present reaction features clean and mild conditions, excellent functional-group tolerance, and high atom economy and scalability, enabling facile applications in pharmaceutical chemistry.
作者机构:
[Teng, Fan; Jin, Xue-Feng; Gui, Qing-Wen; Li, Zhou-Chao; Zhang, Mei; Dai, Jia-Ni] Hunan Agr Univ, Coll Chem & Mat Sci, Changsha 410128, Peoples R China.;[Lin, Ying-Wu] Univ South China, Sch Chem & Chem Engn, Hengyang 421001, Peoples R China.;[He, Wei-Min; Cao, Zhong] Changsha Univ Sci & Technol, Hunan Prov Key Lab Mat Protect Elect Power & Tran, Changsha 410114, Peoples R China.
通讯机构:
[He, Wei-Min] C;Changsha Univ Sci & Technol, Hunan Prov Key Lab Mat Protect Elect Power & Tran, Changsha 410114, Peoples R China.
摘要:
In this work, a variety of α-cyanopyrrolines were efficiently synthesized from alkenes, TMSCN and N,N-disubstituted formamides via molecular iodine-catalyzed tandem reaction under neat and mild conditions. This method applies ambient air as the sole oxidant and circumvents the use of transition metals and extra solvents to afford a broad range of final products with good regio- and chemo-selectivity.
作者机构:
[肖忠良; 宋刘斌; 曹忠; Zeng C.; 刘佩; 吴道新] Changsha University of Science and Technology, School of Chemistry and Food Engineering, Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation, Changsha, 410114, China
通讯机构:
[Song, L.] C;Changsha University of Science and Technology, China
摘要:
Aerobic oxidation using pure dioxygen gas as the oxidant has attracted much attention,but its application in synthetic chemistry has been significantly hampered by the complexity of catalytic system and potential risk of high-energy dioxygen gas.By employing 1,2-diethoxyethane as a catalyst and ambient air as an oxidant,an efficient protocol for the construction of various aryl-alkyl and diaryl ketones through oxidative cleavage of gem-disubstituted aromatic alkenes under minimal solvent conditions has been achieved.
摘要:
A straightforward approach to the fabrication of intrinsically excited-state intramolecular proton transfer (ESIPT)-fluorescent polymer nanoparticles (e-PNPs) was developed. The e-PNPs were obtained by self-assembly of the homopolymers derived from 4-aminosalicylic acid in aqueous solution. By incorporating ESIPT modules into polymer nanoparticles, the ESIPT reaction can be endowed with moderate hydrophobic micro-environment by nanoparticle scaffolds, eliciting enhanced ESIPT emission. The newly developed e-PNPs exhibit strong tautomeric fluorescence(e-FL), good photostability, low-toxicity and favourable biocompatibility in aqueous solution. Upon the addition of NO2(-), the e-FL can be significantly quenched owing to the reaction of NO2(-) with the amide groups on e-PNPs. From this basis, the fluorescence detection of NO2(-) was implemented, which showed a linear relationship between 0nM and 110nM with a detection limit of 2.3nM. Furthermore, e-PNPs were used as nanoprobes to monitor the NO2(-) levels in HeLa cells by fluorescence imaging, demonstrating the ability of discrimination from different concentrations of NO2(-). The proposed method can be applied to a wide range of other ESIPT modules to integrate into polymer nanoparticles and offer highly sensitive nanosensing platform for bioanalysis and molecular imaging.
摘要:
By using ambient air as the oxidant and malic acid as the promoter, a practical method for the preparation of 2-aminobenzothiazoles through visible-light-initiated cascade reaction of aromatic amines and KSCN in eco-friendly bis(methoxypropy)ether under metal-, hazardous additive-, photocatalyst-free conditions was established.