An efficient TfOH-catalyzed O—H insertion reaction of α-aryl diazoesters with carboxylic acids is reported.This metal-free protocol provides an operationally simple method for a one-pot assembly of diverse α-acylox...An efficient TfOH-catalyzed O—H insertion reaction of α-aryl diazoesters with carboxylic acids is reported.This metal-free protocol provides an operationally simple method for a one-pot assembly of diverse α-acyloxy esters in moderate to high yields with a broad substrate scope.All starting materials are readily available,and the reactions can be conducted in the open air at room temperature.展开更多
To improve the low-temperature performances of Li-ion cells, three types of linear carboxylic ester-based electrolyte, such as EC/EMC/EA（1：1：2, mass ratio）, EC/EMC/EP（1：1：2, mass ratio） and EC/EMC/EB（1：1：2,...To improve the low-temperature performances of Li-ion cells, three types of linear carboxylic ester-based electrolyte, such as EC/EMC/EA（1：1：2, mass ratio）, EC/EMC/EP（1：1：2, mass ratio） and EC/EMC/EB（1：1：2, mass ratio）, were prepared to substitute for industrial electrolyte（EC/EMC/DMC）. Then, 18650-type Li Mn2O4-graphite cells（nominal capacity of 1150 mA ·h） were assembled and studied. Results show that the cells containing three types of electrolyte are able to undertake 5C discharging current with above 93% capacity retention at-20 °C. Electrochemical impedance spectra show that the discharge capacity fading of Li-ion cells at low temperature is mainly ascribed to the charge transfer resistance increasing with temperature decreasing. In comparison, the cells containing electrolyte of 1.0 mol/L LiPF6 in EC/EMC/EA（1：1：2, mass ratio） have the highest capacity retention of 90% at-40 °C and 44.41% at-60 °C, due to its lowest charge-transfer resistance.展开更多
Two new phenolic carboxylic acid esters n-butyl eucomate(1) and methyl eucomate (2) and six known compounds eucomic acid(3), 3-β-acetyl-taraxerol (4), friedelin(5),lupenone(6),methyl linoleate(7) and methy...Two new phenolic carboxylic acid esters n-butyl eucomate(1) and methyl eucomate (2) and six known compounds eucomic acid(3), 3-β-acetyl-taraxerol (4), friedelin(5),lupenone(6),methyl linoleate(7) and methyl oleate(8) were isolated from the stems of Opuntia vulgaris Mill(Cactaceae). Their structures were determined on the basis of spectral methods. Compounds 3,4,6,7,8 were isolated for the first time from this plant.展开更多
The increase in anthropogenic carbon dioxide(CO_(2))emissions has exacerbated the deterioration of the global environment,which should be controlled to achieve carbon neutrality.Central to the core goal of achieving c...The increase in anthropogenic carbon dioxide(CO_(2))emissions has exacerbated the deterioration of the global environment,which should be controlled to achieve carbon neutrality.Central to the core goal of achieving carbon neutrality is the utilization of CO_(2) under economic and sustainable conditions.Recently,the strong need for carbon neutrality has led to a proliferation of studies on the direct conversion of CO_(2) into carboxylic acids,which can effectively alleviate CO_(2) emissions and create high-value chemicals.The purpose of this review is to present the application prospects of carboxylic acids and the basic principles of CO_(2) conversion into carboxylic acids through photo-,electric-,and thermal catalysis.Special attention is focused on the regulation strategy of the activity of abundant catalysts at the molecular level,inspiring the preparation of high-performance catalysts.In addition,theoretical calculations,advanced technologies,and numerous typical examples are introduced to elaborate on the corresponding process and influencing factors of catalytic activity.Finally,challenges and prospects are provided for the future development of this field.It is hoped that this review will contribute to a deeper understanding of the conversion of CO_(2) into carboxylic acids and inspire more innovative breakthroughs.展开更多
A carbon paste electrode (CPE) modified with ferrocene carboxylic acid (FcCA) and TiO2 nanoparticles was constructed by incorporating TiO2 nanoparticles and ferrocene carboxylic acid into the carbon paste matrix. The ...A carbon paste electrode (CPE) modified with ferrocene carboxylic acid (FcCA) and TiO2 nanoparticles was constructed by incorporating TiO2 nanoparticles and ferrocene carboxylic acid into the carbon paste matrix. The electrochemical behavior of captopril (CAP) at the surface of the modified electrode was investigated using electroanalytical methods. The modified electrode showed excellent electrocatalytic activity for the oxidation of CAP in aqueous solutions at physiological pH values. Cyclic voltammetric curves showed that the oxidation of CAP at the surface of the modified electrode reduced its overpotential by more than 290 mV. The modified electrode was used for detecting captopril using cyclic voltammetry and square wave voltammetry techniques. A calibration curve in the range of 0.03 to 2400 μmol/L was obtained that had a detection limit of 0.0096 μmol/L (3?) under the optimized conditions. The modified electrode was successfully used for the determination of captopril in pharmaceutical and biological samples.展开更多
An ultrasensitive electrochemical sensor based on polydopamine/carboxylic multi-walled carbon nanotubes(MWCNTs à COOH) nanocomposites modified glassy carbon electrode(GCE) was presented in this work, which has be...An ultrasensitive electrochemical sensor based on polydopamine/carboxylic multi-walled carbon nanotubes(MWCNTs à COOH) nanocomposites modified glassy carbon electrode(GCE) was presented in this work, which has been developed for highly selective and highly sensitive determination of an antimicrobial drug, metronidazole. The preparation of polydopamine/MWCNTs–COOH nanocomposites/GCE sensor is simple and possesses high reproducible, where polydopamine can be coated on the surface of MWCNTs–COOH via a simple electropolymerization process. Under optimized conditions, the proposed sensor showed ultrasensitive determination for metronidazole with a wide linear detection range from5 to 5000 mmol/dm^3 and a low detection limit of 0.25 mmol/dm^3(S/N=3). Moreover, the proposed sensor has been successfully applied for the quantitative determination of metronidazole in real drug samples. This work may provide a novel and effective analytical platform for determination of metronidazole in application of real pharmaceutical and biological samples analysis.展开更多
Sulfonated carbon as a strong and stable solid acid catalyst exhibited excellent catalytic performance in various acid-catalyzed reactions. Here, sulfonated carbon, as catalyst for oxidation reaction, was prepared via...Sulfonated carbon as a strong and stable solid acid catalyst exhibited excellent catalytic performance in various acid-catalyzed reactions. Here, sulfonated carbon, as catalyst for oxidation reaction, was prepared via the carbonization of starch followed by sulfonation with concentrated sulfuric acid. N2 physisorption, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray fluorescence and acid-base titration were used to characterize the obtained materials. The catalytic activity of sulfonated carbon was studied in the oxidation of aldehydes to carboxylic acids using 30 wt% H2O2 as oxidant. This oxidation protocol works well for various aldehydes including aromatic and aliphatic aldehydes. The sulfonated carbon can be recycled for three times without obvious loss of activity.展开更多
Electrochemical fixation of atmospheric pressure of carbon dioxide to organic compounds is a useful and attractive method for synthesizing of various carboxylic acids. Electrochemical fixation of carbon dioxide, elect...Electrochemical fixation of atmospheric pressure of carbon dioxide to organic compounds is a useful and attractive method for synthesizing of various carboxylic acids. Electrochemical fixation of carbon dioxide, electrochemical carboxylation, organic halides, organic triflates, alkenes, aromatic compounds, and carbonyl compounds can readily occur in the presence of an atmospheric pressure of carbon dioxide to form the corresponding carboxylic acids with high yields, when a sacrificial anode such as magnesium or aluminum is used in the electrolysis. The electrochemical carboxylation of vinyl bromides was successfully applied for the synthesis of the precursor of nonsteroidal anti-inflammatory agents such as ibuprofen and naproxen. On the other hand, supercritical carbon dioxide （scCO2） has significant potential as an environmentally benign solvent in organic synthesis and it could be used both as a solvent and as a reagent in these electrochemical carboxylations by using a small amount of cosolvent.展开更多
A series of novel phenylpyrazole carboxylic acid derivatives containing fluorine moiety,i.e.,diamides 11,simple aryl-bearing amides 12 and acylthioureas 14 were successfully synthesized based on the key fluo ro-contai...A series of novel phenylpyrazole carboxylic acid derivatives containing fluorine moiety,i.e.,diamides 11,simple aryl-bearing amides 12 and acylthioureas 14 were successfully synthesized based on the key fluo ro-containing phe nylpyrazole acid intermediate.The new compounds were identified and confirmed by melting point,1H NMR,13C NMR and elemental analysis or HRMS.The bioassay results indicated that some of the compounds possessed excellent insecticidal activities towards oriental armyworm,diamondback moth and corn borer at low concentrations.For examples,compounds 11a,11e-g and 14b exhibited remarkable larvicidal activities with LC50 values of 0.13-0.39 mg/L and 0.0002-0.0014 mg/L against oriental armyworm and diamondback moth,respectively,were comparable with those of the control chlorantraniliprole.Particularly,lie were found superior to chlorantraniliprole in oriental armyworm tests(LC50:0.23 mg/L vs.0.26 mg/L);11a,lie,11f and 14c in diamondback moth tests with LC50 values of 0.0002 mg/L,0.0002 mg/L,0.0008 mg/L and 0.0005 mg/L,respectively,we re more effective than that of chlorantraniliprole.In addition,12 a also showed a promising insecticidal potential and development/optimization advantage.Compounds 11a,lle-g,12a,14b and 14c could be considered as possible new leading structures for further study.The SAR investigation indicated that the compounds with fluorine motif(e.g.,-F,-CF2H,-CF3)held apparently favorable insecticidal potentials,which provided useful guidance for further design/development of new phenylpyrazole-containing agrochemicals.展开更多
A metal-free cross coupling between common CH2Cl2 and carboxylic acids has been achieved with K2CO3 as the sole additive. This simple protocol is a convenient and cost-effective route to synthesize methylene diesters ...A metal-free cross coupling between common CH2Cl2 and carboxylic acids has been achieved with K2CO3 as the sole additive. This simple protocol is a convenient and cost-effective route to synthesize methylene diesters from a wide scope of carboxylic acids substrates with good functional group tolerance. Several gram-scale reactions have been performed to evaluate the effectiveness and practicality of this protocol.展开更多
A yellow, alkali-clearable azo disperse dye containing a carboxylic ester moiety was readily synthesized from the reactant p-aminobenzoic acid by successive diazotization, coupling reaction, chlorination and esterific...A yellow, alkali-clearable azo disperse dye containing a carboxylic ester moiety was readily synthesized from the reactant p-aminobenzoic acid by successive diazotization, coupling reaction, chlorination and esterification with ethanol. Then its molecular structure was characterized by FTIR,1H NMR,13 C NMR,mass spectrometry and elemental analysis. The synthesized dye and a similar control dye containing the acylamide moiety（I） were applied to dyeing poly（ethylene terephthalate） fabric and their washing and rubbing fastness properties with different post-treatment methods（reduction clearing and alkali clearing） were examined and compared. It is found that the ester-containing disperse dye shows good alkali-clear ability on poly（ethylene terephthalate） fabric and contaminates little to environment due to the absence of reductants, as well as low toxicity and easy recycling of the hydrolysates.展开更多
The 1,2-dibromoethane-and Kl-mediatedα-acyloxylation of ketones is reported in moderate to good yield without the use of transition metals and strong oxidants.Various acids are well tolerated with wide functional gro...The 1,2-dibromoethane-and Kl-mediatedα-acyloxylation of ketones is reported in moderate to good yield without the use of transition metals and strong oxidants.Various acids are well tolerated with wide functional group compatibility.An 1,2-dibromoethane-and Kl-catalysed reaction mechanism is proposed based on the results of control experiments.展开更多
Benzimidazole amino acid derivatives behave as supramolecular hosts to include organic acids via complementary hydrogen bonding whereby supramolecular chirality and chiroptical properties could be manipulated.Organic ...Benzimidazole amino acid derivatives behave as supramolecular hosts to include organic acids via complementary hydrogen bonding whereby supramolecular chirality and chiroptical properties could be manipulated.Organic acids enhanced the chiral assembly that showed tunable circularly polarized luminescence with high dissymmetry g-factors at 10^(-2)grade.展开更多
Three high-acidity crudes, Dar, SZ36-1, and QHD326, were separated through distillation into several fractions, including diesel distillates, and VGOs. Samples were characterized by negative-ion ESI FT-ICR MS. The O2 ...Three high-acidity crudes, Dar, SZ36-1, and QHD326, were separated through distillation into several fractions, including diesel distillates, and VGOs. Samples were characterized by negative-ion ESI FT-ICR MS. The O2 class species （petroleum carboxylic acids）, which have a close relationship with corrosion of equipment caused by high-acidity crudes, were put in the focus of attention and were discussed in this paper. Monocyclic, bicyclic, and tricyclic naphthenic acids are the main types of petroleum carboxylic acids in naphthenic-base crudes （SZ36-1 and QHD326）. But the main types of petroleum carboxylic acids in paraffinic-base crude （Dar） are aliphatic acids and monocyclic naphthenic acids. The O2 class species in SZ36-1 and QHD326 are distributed in a wider range and have bigger DBE value （double-bond equivalence value） and carbon number than Dar. Bicyclic naphthenic acids have the highest proportion among petroleum carboxylie acids in diesel distillates, but monocyclic and tricyclic naphthenic acids also occupy a high proportion. Particularly, aliphatic acids in the diesel distillate of Dar still have high proportion among petroleum carboxylic acids. The distribution of petroleum carboxylic acids in VGO is basically identical. The bicyclic naphthenic acids assume the first place （about 25 m%）, while the monocyclic and tricyclic naphthenic acids take the next place. The comparison of petroleum carboxylic acids in diesel distillates and VGOs has revealed that the molecules of carboxylic acids in VGOs are not only bigger but also more complicated.展开更多
Silver-catalyzed decarboxylative C–H alkylation of cyclic aldimines with abundant aliphatic carboxylic acids has been realized under mild reaction conditions generating the corresponding products in moderate to good ...Silver-catalyzed decarboxylative C–H alkylation of cyclic aldimines with abundant aliphatic carboxylic acids has been realized under mild reaction conditions generating the corresponding products in moderate to good yields(32%–91%).In addition,a gram-scale reaction,late-stage modification of drug,synthetic transformation of the product,and further application of the catalytic strategy were also performed.Preliminary studies indicate that the reaction undergoes a radical process.展开更多
To examine a） the effect of organophosphorus pesticide exposure on activity of carboxylic esterases, namely butyrylcholinesterase （BChE）, carboxylesterase （CarbE） and paraoxonase （PonE）; and b） the association...To examine a） the effect of organophosphorus pesticide exposure on activity of carboxylic esterases, namely butyrylcholinesterase （BChE）, carboxylesterase （CarbE） and paraoxonase （PonE）; and b） the association of polymorphisms of BChE and PonE with individual genetic susceptibility to organophosphorus pesticide exposure. Methods A cross-sectional study was conducted in 75 workers exposed to organophosphorus pesticides and 100 non-exposed controls. The serum activity of these enzymes was measured. Variant forms of BCHE-K, PON-192, and PON-55 were detected. A symptom score was developed as a proxy measure of clinical outcomes. Results Activities of both BChE and CarbE were lower in exposed workers （27.3±21.65 runol.hl.mL^-l and 235.6±104.03 nmol-min^-l.mL^-l） than in non-exposed workers （78.313±30.354 nmol.h^-l.mL^-1 and 362.681_＋194.997 nmol.min^-1.mL^-1）. The activity of PonE was not associated with exposure status. The AChE activity in the exposed workers with BCHE-K genotype UU （61 cases）, genotype UK （12 cases） and genotype KK （2 cases） was 105.05, 84.42 and 79.00 mmol-h^-1.mL^-1, respectively and the accumulative symptom scores were 3.74, 9.17, and 12.50 accordingly. The AChE activity in the exposed workers with PON-192 genotype BB （37）, genotype AB （27） and genotype AA （11） was 116.8, 91.2, and 72,3 mmol-h^-1.mL^-1, respectively and the symptom scores were 2.00, 6.74, and 9.73 accordingly. The AChE activity in those with PON-55 genotype LL （70） and genotype LM （5） was 102.4 and 82.8 mmol-h^-1.mL^-1 and the symptom scores were 4.53 and 9.20. The symptom score was the highest in individuals with abnormal homozygote for each of the three gene loci. Condusions Long-term exposure to organophosphorus pesticides can inhibit BChE and CarbE activity, but exerts no inhibitory effect on PonE activity. Different genotypes of BCHE-K, PON-192, and PON-55 may be related to the severity of adverse health effects of organophosphorus pesticide exposure. Implications of potentially higher susceptibility of workers with mutant homozygotes should be evaluated to reduce health risks.展开更多
Natural long-chain alkanol and alkyl carboxylic acid were used to prepare novel hydrophobic deep eutectic solvents(HDESs).These HDESs are liquid at room temperature and have low viscosity(<12.26 mPa·s),low pol...Natural long-chain alkanol and alkyl carboxylic acid were used to prepare novel hydrophobic deep eutectic solvents(HDESs).These HDESs are liquid at room temperature and have low viscosity(<12.26 mPa·s),low polarity(lower than that of methanol,ChCl-based deep eutectic solvents and other reported HDESs),and low density(<0.928 g/mL).A simple one-pot method based on a novel HDES-water two-phase extraction system was constructed for the extraction of weak-polarity bioactive components,anthraquinones,from Rhei Radix et Rhizoma.This HDES-based new extraction method does not consume hazardous organic solvents and can obtain a total anthraquinone yield of 21.52 mg/g,which is close to that obtained by the Chinese pharmacopoeia method(21.22 mg/g)and considerably higher than those by other reported HDESs-based extraction methods(14.20-20.09 mg/g,p<0.01).The high extraction yield can be mainly attributed to the severe destruction of the RRR cell walls by the extraction system and the excellent dissolving ability of novel HDESs for anthraquinones.展开更多
Catalytic reduction systems of 2-furancarboxylic acid(FCA)and 2,5-furandicarboxylic acid(FDCA)with H 2 without reduction of the carboxyl groups are reviewed.FCA and FDCA are produced from furfural and 5-hydroxymethylf...Catalytic reduction systems of 2-furancarboxylic acid(FCA)and 2,5-furandicarboxylic acid(FDCA)with H 2 without reduction of the carboxyl groups are reviewed.FCA and FDCA are produced from furfural and 5-hydroxymethylfurfural which are important platform chemicals in biomass conversions.Furan ring hydrogenation to tetrahydrofuran-2-carboxylic acid(THFCA)and tetrahydrofuran-2,5-dicarboxylic acid(THFDCA)easily proceeds over Pd catalysts.Hydrogenolysis of one C–O bond in the furan ring produces 5-hydroxyvaleric acid(5-HVA)and 2-hydroxyadipic acid.2-Hydroxyvaleric acid is not produced in the reported systems.5-HVA can be produced as the lactone form(δ-valerolactone;DVL)or as the esters depending on the solvent.These reactions proceed over Pt catalysts with good yields(~70%)at optimized conditions.Hydrogenolysis of two C–O bonds in the furan ring produces valeric acid and adipic acid,the latter of which is a very important chemical in industry and its production from biomass is of high importance.Adipic acid from FDCA can be produced directly over Pt-MoO_(x) catalyst,indirectly via hydrogenation and hydrodeoxygenation as one-pot reaction using the combination of Pt and acid catalysts such as Pt/niobium oxide,or indirectly via two-step reaction composed of hydrogenation catalyzed by Pd and hydrodeoxygenation catalyzed by iodide ion in acidic conditions.Only the two-step method can give good yield of adipic acid at present.展开更多
The title compounds 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carboxylic acid（C11H9Cl N2O2, HL）（1） and [Cu（L）2（H2O）]（2） were prepared and structurally characterized by elemental analysis, IR and single-crysta...The title compounds 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carboxylic acid（C11H9Cl N2O2, HL）（1） and [Cu（L）2（H2O）]（2） were prepared and structurally characterized by elemental analysis, IR and single-crystal X-ray diffraction. Compound 1（C11H9Cl N2O2） crystallizes in the monoclinic system, space group P21/n with a = 7.249（3）, b = 20.515（10）, c = 7.249（3）,β= 96.30°, V = 1071.6（9） ？3, Z = 4, Mr = 236.65, Dc = 1.467 g/cm3, F（000） = 488, GOOF = 1.029, μ= 0.341 mm-1, the final R = 0.0736 and w R = 0.1966 for 1500 observed reflections with I 〉 2σ（I）. Compound 2（C22H18Cl2Cu N4O5） crystallizes in the monoclinic system, space group P21/c with a = 7.2931（6）, b = 24.548（2）, c = 13.2726（11）, β= 99.4040（10）°, V = 2344.2（3） ？3, Z = 4, Mr = 552.84, Dc = 1.566 g/cm3, F（000） = 1124, GOOF = 1.050, μ= 1.201 mm-1, the final R = 0.0376 and w R = 0.1000 for 3626 observed reflections with I 〉 2σ（I）. 1 and 2 are connected through hydrogen bonding interactions to generate 2D and 3D supramolecular structures, respectively. Moreover, the preliminary antibacterial activities of 1 and 2 against the gram positive bacteria（S. aureus, C. albicans and B. subtilis） and gram negative bacteria（E. coli and P. aeruginosa） have been tested by using the microdilution method, and the results indicate that 2 is more active than 1 against the tested bacteria.展开更多
A highly efficient copper-catalyzed approach to form amide bonds from formamides and carboxylic acids was developed. This protocol shows broad substrate scopes and high yields in the presence of 1 mol% catalyst and 4....A highly efficient copper-catalyzed approach to form amide bonds from formamides and carboxylic acids was developed. This protocol shows broad substrate scopes and high yields in the presence of 1 mol% catalyst and 4.0 equiv, formamides.展开更多
文摘An efficient TfOH-catalyzed O—H insertion reaction of α-aryl diazoesters with carboxylic acids is reported.This metal-free protocol provides an operationally simple method for a one-pot assembly of diverse α-acyloxy esters in moderate to high yields with a broad substrate scope.All starting materials are readily available,and the reactions can be conducted in the open air at room temperature.
基金Project(2007BAE12B01)supported by the National Key Technology Research and Development Program of ChinaProject(20803095)supported by the National Natural Science Foundation of China
文摘To improve the low-temperature performances of Li-ion cells, three types of linear carboxylic ester-based electrolyte, such as EC/EMC/EA（1：1：2, mass ratio）, EC/EMC/EP（1：1：2, mass ratio） and EC/EMC/EB（1：1：2, mass ratio）, were prepared to substitute for industrial electrolyte（EC/EMC/DMC）. Then, 18650-type Li Mn2O4-graphite cells（nominal capacity of 1150 mA ·h） were assembled and studied. Results show that the cells containing three types of electrolyte are able to undertake 5C discharging current with above 93% capacity retention at-20 °C. Electrochemical impedance spectra show that the discharge capacity fading of Li-ion cells at low temperature is mainly ascribed to the charge transfer resistance increasing with temperature decreasing. In comparison, the cells containing electrolyte of 1.0 mol/L LiPF6 in EC/EMC/EA（1：1：2, mass ratio） have the highest capacity retention of 90% at-40 °C and 44.41% at-60 °C, due to its lowest charge-transfer resistance.
文摘Two new phenolic carboxylic acid esters n-butyl eucomate(1) and methyl eucomate (2) and six known compounds eucomic acid(3), 3-β-acetyl-taraxerol (4), friedelin(5),lupenone(6),methyl linoleate(7) and methyl oleate(8) were isolated from the stems of Opuntia vulgaris Mill(Cactaceae). Their structures were determined on the basis of spectral methods. Compounds 3,4,6,7,8 were isolated for the first time from this plant.
基金financial support from the King Abdullah University of Science and Technology(KAUST).
文摘The increase in anthropogenic carbon dioxide(CO_(2))emissions has exacerbated the deterioration of the global environment,which should be controlled to achieve carbon neutrality.Central to the core goal of achieving carbon neutrality is the utilization of CO_(2) under economic and sustainable conditions.Recently,the strong need for carbon neutrality has led to a proliferation of studies on the direct conversion of CO_(2) into carboxylic acids,which can effectively alleviate CO_(2) emissions and create high-value chemicals.The purpose of this review is to present the application prospects of carboxylic acids and the basic principles of CO_(2) conversion into carboxylic acids through photo-,electric-,and thermal catalysis.Special attention is focused on the regulation strategy of the activity of abundant catalysts at the molecular level,inspiring the preparation of high-performance catalysts.In addition,theoretical calculations,advanced technologies,and numerous typical examples are introduced to elaborate on the corresponding process and influencing factors of catalytic activity.Finally,challenges and prospects are provided for the future development of this field.It is hoped that this review will contribute to a deeper understanding of the conversion of CO_(2) into carboxylic acids and inspire more innovative breakthroughs.
文摘A carbon paste electrode (CPE) modified with ferrocene carboxylic acid (FcCA) and TiO2 nanoparticles was constructed by incorporating TiO2 nanoparticles and ferrocene carboxylic acid into the carbon paste matrix. The electrochemical behavior of captopril (CAP) at the surface of the modified electrode was investigated using electroanalytical methods. The modified electrode showed excellent electrocatalytic activity for the oxidation of CAP in aqueous solutions at physiological pH values. Cyclic voltammetric curves showed that the oxidation of CAP at the surface of the modified electrode reduced its overpotential by more than 290 mV. The modified electrode was used for detecting captopril using cyclic voltammetry and square wave voltammetry techniques. A calibration curve in the range of 0.03 to 2400 μmol/L was obtained that had a detection limit of 0.0096 μmol/L (3?) under the optimized conditions. The modified electrode was successfully used for the determination of captopril in pharmaceutical and biological samples.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.21475046,21427809)
文摘An ultrasensitive electrochemical sensor based on polydopamine/carboxylic multi-walled carbon nanotubes(MWCNTs à COOH) nanocomposites modified glassy carbon electrode(GCE) was presented in this work, which has been developed for highly selective and highly sensitive determination of an antimicrobial drug, metronidazole. The preparation of polydopamine/MWCNTs–COOH nanocomposites/GCE sensor is simple and possesses high reproducible, where polydopamine can be coated on the surface of MWCNTs–COOH via a simple electropolymerization process. Under optimized conditions, the proposed sensor showed ultrasensitive determination for metronidazole with a wide linear detection range from5 to 5000 mmol/dm^3 and a low detection limit of 0.25 mmol/dm^3(S/N=3). Moreover, the proposed sensor has been successfully applied for the quantitative determination of metronidazole in real drug samples. This work may provide a novel and effective analytical platform for determination of metronidazole in application of real pharmaceutical and biological samples analysis.
基金supported by the National Nature Science Foundation of China (J1210060, 21143002)
文摘Sulfonated carbon as a strong and stable solid acid catalyst exhibited excellent catalytic performance in various acid-catalyzed reactions. Here, sulfonated carbon, as catalyst for oxidation reaction, was prepared via the carbonization of starch followed by sulfonation with concentrated sulfuric acid. N2 physisorption, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray fluorescence and acid-base titration were used to characterize the obtained materials. The catalytic activity of sulfonated carbon was studied in the oxidation of aldehydes to carboxylic acids using 30 wt% H2O2 as oxidant. This oxidation protocol works well for various aldehydes including aromatic and aliphatic aldehydes. The sulfonated carbon can be recycled for three times without obvious loss of activity.
文摘Electrochemical fixation of atmospheric pressure of carbon dioxide to organic compounds is a useful and attractive method for synthesizing of various carboxylic acids. Electrochemical fixation of carbon dioxide, electrochemical carboxylation, organic halides, organic triflates, alkenes, aromatic compounds, and carbonyl compounds can readily occur in the presence of an atmospheric pressure of carbon dioxide to form the corresponding carboxylic acids with high yields, when a sacrificial anode such as magnesium or aluminum is used in the electrolysis. The electrochemical carboxylation of vinyl bromides was successfully applied for the synthesis of the precursor of nonsteroidal anti-inflammatory agents such as ibuprofen and naproxen. On the other hand, supercritical carbon dioxide （scCO2） has significant potential as an environmentally benign solvent in organic synthesis and it could be used both as a solvent and as a reagent in these electrochemical carboxylations by using a small amount of cosolvent.
基金financially supported by the National Key Research and Development Program of China(No.2017YFD0200505)the National Natural Science Foundation of China(No.21772103)Tianjin Natural Science Foundation(No.17JCYBJC19900)。
文摘A series of novel phenylpyrazole carboxylic acid derivatives containing fluorine moiety,i.e.,diamides 11,simple aryl-bearing amides 12 and acylthioureas 14 were successfully synthesized based on the key fluo ro-containing phe nylpyrazole acid intermediate.The new compounds were identified and confirmed by melting point,1H NMR,13C NMR and elemental analysis or HRMS.The bioassay results indicated that some of the compounds possessed excellent insecticidal activities towards oriental armyworm,diamondback moth and corn borer at low concentrations.For examples,compounds 11a,11e-g and 14b exhibited remarkable larvicidal activities with LC50 values of 0.13-0.39 mg/L and 0.0002-0.0014 mg/L against oriental armyworm and diamondback moth,respectively,were comparable with those of the control chlorantraniliprole.Particularly,lie were found superior to chlorantraniliprole in oriental armyworm tests(LC50:0.23 mg/L vs.0.26 mg/L);11a,lie,11f and 14c in diamondback moth tests with LC50 values of 0.0002 mg/L,0.0002 mg/L,0.0008 mg/L and 0.0005 mg/L,respectively,we re more effective than that of chlorantraniliprole.In addition,12 a also showed a promising insecticidal potential and development/optimization advantage.Compounds 11a,lle-g,12a,14b and 14c could be considered as possible new leading structures for further study.The SAR investigation indicated that the compounds with fluorine motif(e.g.,-F,-CF2H,-CF3)held apparently favorable insecticidal potentials,which provided useful guidance for further design/development of new phenylpyrazole-containing agrochemicals.
基金Financial support from the National Natural Science Foundation of China(NSFC, Nos. 21761021 and 21571094)Natural Science Foundation of Jiangxi Province(No. 20171BAB203002)Sci & Tech Project of Education Department of Jiangxi Province(No. 60007)
文摘A metal-free cross coupling between common CH2Cl2 and carboxylic acids has been achieved with K2CO3 as the sole additive. This simple protocol is a convenient and cost-effective route to synthesize methylene diesters from a wide scope of carboxylic acids substrates with good functional group tolerance. Several gram-scale reactions have been performed to evaluate the effectiveness and practicality of this protocol.
基金supported by the National Natural Science Foundation of China(Nos.51173168,21106135)Zhejiang Provincial Key Innovation Team(No.2010R50038)+1 种基金Zhejiang Provincial Top Key Academic Discipline of Chemical Engineering and Technology of Zhejiang Sci-Tech University‘‘521’’ Talent Project of Zhejiang Sci-Tech University
文摘A yellow, alkali-clearable azo disperse dye containing a carboxylic ester moiety was readily synthesized from the reactant p-aminobenzoic acid by successive diazotization, coupling reaction, chlorination and esterification with ethanol. Then its molecular structure was characterized by FTIR,1H NMR,13 C NMR,mass spectrometry and elemental analysis. The synthesized dye and a similar control dye containing the acylamide moiety（I） were applied to dyeing poly（ethylene terephthalate） fabric and their washing and rubbing fastness properties with different post-treatment methods（reduction clearing and alkali clearing） were examined and compared. It is found that the ester-containing disperse dye shows good alkali-clear ability on poly（ethylene terephthalate） fabric and contaminates little to environment due to the absence of reductants, as well as low toxicity and easy recycling of the hydrolysates.
基金the Drug Innovation Major Project(No.2018ZX09711001-001-001)CAMS Innovation Fund for Medical Sciences(CIFMS)(No.2016-I2M-1-010)for financial support。
文摘The 1,2-dibromoethane-and Kl-mediatedα-acyloxylation of ketones is reported in moderate to good yield without the use of transition metals and strong oxidants.Various acids are well tolerated with wide functional group compatibility.An 1,2-dibromoethane-and Kl-catalysed reaction mechanism is proposed based on the results of control experiments.
基金supported by the National Natural Science Foundation of China(Nos.21901145,22171165)the financial support from Youth Cross-Scientific Innovation Group of Shandong University(No.2020QNQT003)。
文摘Benzimidazole amino acid derivatives behave as supramolecular hosts to include organic acids via complementary hydrogen bonding whereby supramolecular chirality and chiroptical properties could be manipulated.Organic acids enhanced the chiral assembly that showed tunable circularly polarized luminescence with high dissymmetry g-factors at 10^(-2)grade.
文摘Three high-acidity crudes, Dar, SZ36-1, and QHD326, were separated through distillation into several fractions, including diesel distillates, and VGOs. Samples were characterized by negative-ion ESI FT-ICR MS. The O2 class species （petroleum carboxylic acids）, which have a close relationship with corrosion of equipment caused by high-acidity crudes, were put in the focus of attention and were discussed in this paper. Monocyclic, bicyclic, and tricyclic naphthenic acids are the main types of petroleum carboxylic acids in naphthenic-base crudes （SZ36-1 and QHD326）. But the main types of petroleum carboxylic acids in paraffinic-base crude （Dar） are aliphatic acids and monocyclic naphthenic acids. The O2 class species in SZ36-1 and QHD326 are distributed in a wider range and have bigger DBE value （double-bond equivalence value） and carbon number than Dar. Bicyclic naphthenic acids have the highest proportion among petroleum carboxylie acids in diesel distillates, but monocyclic and tricyclic naphthenic acids also occupy a high proportion. Particularly, aliphatic acids in the diesel distillate of Dar still have high proportion among petroleum carboxylic acids. The distribution of petroleum carboxylic acids in VGO is basically identical. The bicyclic naphthenic acids assume the first place （about 25 m%）, while the monocyclic and tricyclic naphthenic acids take the next place. The comparison of petroleum carboxylic acids in diesel distillates and VGOs has revealed that the molecules of carboxylic acids in VGOs are not only bigger but also more complicated.
基金financially supported by the National Natural Science Foundation of China(Nos.21402116,21502111,21572126)the Science and Technology Innovation Talents of Henan Province(No.2018JQ0011)the Key Science Research of Education Committee in Henan Province(No.21A150044)。
文摘Silver-catalyzed decarboxylative C–H alkylation of cyclic aldimines with abundant aliphatic carboxylic acids has been realized under mild reaction conditions generating the corresponding products in moderate to good yields(32%–91%).In addition,a gram-scale reaction,late-stage modification of drug,synthetic transformation of the product,and further application of the catalytic strategy were also performed.Preliminary studies indicate that the reaction undergoes a radical process.
基金This work was supported by the grant from National 973 Project (2002CB512902) and the grant from Shanghai Shuguang Program.
文摘To examine a） the effect of organophosphorus pesticide exposure on activity of carboxylic esterases, namely butyrylcholinesterase （BChE）, carboxylesterase （CarbE） and paraoxonase （PonE）; and b） the association of polymorphisms of BChE and PonE with individual genetic susceptibility to organophosphorus pesticide exposure. Methods A cross-sectional study was conducted in 75 workers exposed to organophosphorus pesticides and 100 non-exposed controls. The serum activity of these enzymes was measured. Variant forms of BCHE-K, PON-192, and PON-55 were detected. A symptom score was developed as a proxy measure of clinical outcomes. Results Activities of both BChE and CarbE were lower in exposed workers （27.3±21.65 runol.hl.mL^-l and 235.6±104.03 nmol-min^-l.mL^-l） than in non-exposed workers （78.313±30.354 nmol.h^-l.mL^-1 and 362.681_＋194.997 nmol.min^-1.mL^-1）. The activity of PonE was not associated with exposure status. The AChE activity in the exposed workers with BCHE-K genotype UU （61 cases）, genotype UK （12 cases） and genotype KK （2 cases） was 105.05, 84.42 and 79.00 mmol-h^-1.mL^-1, respectively and the accumulative symptom scores were 3.74, 9.17, and 12.50 accordingly. The AChE activity in the exposed workers with PON-192 genotype BB （37）, genotype AB （27） and genotype AA （11） was 116.8, 91.2, and 72,3 mmol-h^-1.mL^-1, respectively and the symptom scores were 2.00, 6.74, and 9.73 accordingly. The AChE activity in those with PON-55 genotype LL （70） and genotype LM （5） was 102.4 and 82.8 mmol-h^-1.mL^-1 and the symptom scores were 4.53 and 9.20. The symptom score was the highest in individuals with abnormal homozygote for each of the three gene loci. Condusions Long-term exposure to organophosphorus pesticides can inhibit BChE and CarbE activity, but exerts no inhibitory effect on PonE activity. Different genotypes of BCHE-K, PON-192, and PON-55 may be related to the severity of adverse health effects of organophosphorus pesticide exposure. Implications of potentially higher susceptibility of workers with mutant homozygotes should be evaluated to reduce health risks.
基金the National Natural Science Foundation of China(Grant Nos.:81673394 and 82073811)the Fundamental Research Funds for the Central Universities(Grant No.:2042020kf1010)the Large-scale Instrument and Equipment Sharing Foundation of Wuhan University(Grant No.:LF20170838)
文摘Natural long-chain alkanol and alkyl carboxylic acid were used to prepare novel hydrophobic deep eutectic solvents(HDESs).These HDESs are liquid at room temperature and have low viscosity(<12.26 mPa·s),low polarity(lower than that of methanol,ChCl-based deep eutectic solvents and other reported HDESs),and low density(<0.928 g/mL).A simple one-pot method based on a novel HDES-water two-phase extraction system was constructed for the extraction of weak-polarity bioactive components,anthraquinones,from Rhei Radix et Rhizoma.This HDES-based new extraction method does not consume hazardous organic solvents and can obtain a total anthraquinone yield of 21.52 mg/g,which is close to that obtained by the Chinese pharmacopoeia method(21.22 mg/g)and considerably higher than those by other reported HDESs-based extraction methods(14.20-20.09 mg/g,p<0.01).The high extraction yield can be mainly attributed to the severe destruction of the RRR cell walls by the extraction system and the excellent dissolving ability of novel HDESs for anthraquinones.
基金This work was financially supported by New Energy and Industrial Technology Development Organization(NEDO)under the program of Extensive Support for Young Promising Researchers.
文摘Catalytic reduction systems of 2-furancarboxylic acid(FCA)and 2,5-furandicarboxylic acid(FDCA)with H 2 without reduction of the carboxyl groups are reviewed.FCA and FDCA are produced from furfural and 5-hydroxymethylfurfural which are important platform chemicals in biomass conversions.Furan ring hydrogenation to tetrahydrofuran-2-carboxylic acid(THFCA)and tetrahydrofuran-2,5-dicarboxylic acid(THFDCA)easily proceeds over Pd catalysts.Hydrogenolysis of one C–O bond in the furan ring produces 5-hydroxyvaleric acid(5-HVA)and 2-hydroxyadipic acid.2-Hydroxyvaleric acid is not produced in the reported systems.5-HVA can be produced as the lactone form(δ-valerolactone;DVL)or as the esters depending on the solvent.These reactions proceed over Pt catalysts with good yields(~70%)at optimized conditions.Hydrogenolysis of two C–O bonds in the furan ring produces valeric acid and adipic acid,the latter of which is a very important chemical in industry and its production from biomass is of high importance.Adipic acid from FDCA can be produced directly over Pt-MoO_(x) catalyst,indirectly via hydrogenation and hydrodeoxygenation as one-pot reaction using the combination of Pt and acid catalysts such as Pt/niobium oxide,or indirectly via two-step reaction composed of hydrogenation catalyzed by Pd and hydrodeoxygenation catalyzed by iodide ion in acidic conditions.Only the two-step method can give good yield of adipic acid at present.
基金Supported by the National Natural Science Foundation of China(No.20662007)the Bureau of Education of Jiangxi Province(No.GJJ09064)Jiangxi Science and Technology Support Program(20112BBF60009)
文摘The title compounds 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carboxylic acid（C11H9Cl N2O2, HL）（1） and [Cu（L）2（H2O）]（2） were prepared and structurally characterized by elemental analysis, IR and single-crystal X-ray diffraction. Compound 1（C11H9Cl N2O2） crystallizes in the monoclinic system, space group P21/n with a = 7.249（3）, b = 20.515（10）, c = 7.249（3）,β= 96.30°, V = 1071.6（9） ？3, Z = 4, Mr = 236.65, Dc = 1.467 g/cm3, F（000） = 488, GOOF = 1.029, μ= 0.341 mm-1, the final R = 0.0736 and w R = 0.1966 for 1500 observed reflections with I 〉 2σ（I）. Compound 2（C22H18Cl2Cu N4O5） crystallizes in the monoclinic system, space group P21/c with a = 7.2931（6）, b = 24.548（2）, c = 13.2726（11）, β= 99.4040（10）°, V = 2344.2（3） ？3, Z = 4, Mr = 552.84, Dc = 1.566 g/cm3, F（000） = 1124, GOOF = 1.050, μ= 1.201 mm-1, the final R = 0.0376 and w R = 0.1000 for 3626 observed reflections with I 〉 2σ（I）. 1 and 2 are connected through hydrogen bonding interactions to generate 2D and 3D supramolecular structures, respectively. Moreover, the preliminary antibacterial activities of 1 and 2 against the gram positive bacteria（S. aureus, C. albicans and B. subtilis） and gram negative bacteria（E. coli and P. aeruginosa） have been tested by using the microdilution method, and the results indicate that 2 is more active than 1 against the tested bacteria.
基金supported by the National Natural Science Foundation of China(No.21372176)Tongji University 985 Phase Ⅲ funds+1 种基金Pujiang Project of Shanghai Science and Technology Commission(No.11 J1409800)the Program for Professor of Special Appointment(Eastern Scholar) at Shanghai Institutions of Higher Learning
文摘A highly efficient copper-catalyzed approach to form amide bonds from formamides and carboxylic acids was developed. This protocol shows broad substrate scopes and high yields in the presence of 1 mol% catalyst and 4.0 equiv, formamides.
