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
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
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
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
A mild,efficient and simple method for the preparation of acyl azides from carboxylic acids using chlorodiphenylphosphine in the presence of molecular iodine and sodium azide is described.
The selective catalytic hydrogenation of carboxylic acids is an important process for alcohol production,while efficient heterogeneous catalyst systems are still being explored.Here,we report the selective hydrogenati...The selective catalytic hydrogenation of carboxylic acids is an important process for alcohol production,while efficient heterogeneous catalyst systems are still being explored.Here,we report the selective hydrogenation of carboxylic acids using earth‐abundant cobalt oxides through a reaction‐controlled catalysis process.The further reaction of the alcohols is completely hindered by the presence of carboxylic acids in the reaction system.The partial reduction of cobalt oxides by hydrogen at designated temperatures can dramatically enhance the catalytic activity of pristine samples.A wide range of carboxylic acids with a variety of functional groups can be converted to the corresponding alcohols at a yield level applicable to large‐scale production.Cobalt monoxide was established as the preferred active phase for the selective hydrogenation of carboxylic acids.展开更多
The potential energy difference of trivalent Pr/Nd complex ions with various α hydroxyl carboxylic acids were computed by molecular mechanics plus(MM +) model. Its relationships with the steric hindrance of the...The potential energy difference of trivalent Pr/Nd complex ions with various α hydroxyl carboxylic acids were computed by molecular mechanics plus(MM +) model. Its relationships with the steric hindrance of the coordinating lignads and with the separation factor of Pr/Nd were discussed. It is found that the MM + model can be used for selecting and designing ligand as effective eluant, with which Pr 3+ and Nd 3+ can be separated by ion exchange chromatography.展开更多
Aromatic carboxylic acids(ACAs)may be as transformed key metabolites via gut microbiome for playing better pharmacological effects.However,it's rare to achieve high-specificity,high-sensitivity,and highthroughput ...Aromatic carboxylic acids(ACAs)may be as transformed key metabolites via gut microbiome for playing better pharmacological effects.However,it's rare to achieve high-specificity,high-sensitivity,and highthroughput detection simultaneously,especially,for tracing trace ACAs in gut microbiome.In this work,firstly,a novel dual-template and double-shelled molecularly imprinted 96-well microplates(DDMIPs)was designed and amplified signal for p-hydroxybenzoic acid(PBA)and 3,4,5-trimethoxycinnamic acid(TMA).Additionally,the DDMIPs and a stable isotope labeling derivatization(SILD)method combined with the ultra-high performance liquid chromatography triple quadrupole tandem mass spectrometry(UHPLC-TQ MS)was firstly stepwise integrated,achieving high-effective,high-sensitive,and highthroughput study of gut microbiome metabolism.The whole strategy showed lower limits of detections(LODs)up to 1000 folds than the traditional method,and revealed a more real metabolism-time profile of PBA and TMA by 3-step signal amplification.The platform also laid the foundation for fast,simple,high-selective,high-effective,and high-throughput metabolism and pharmacological research.展开更多
The Dar crude oil produced in Sudan was distilled into several fractions. The heteroatom class species in crude and its fractions were characterized by the negative-ion ESI FT-ICR MS. The major emphasis was put upon t...The Dar crude oil produced in Sudan was distilled into several fractions. The heteroatom class species in crude and its fractions were characterized by the negative-ion ESI FT-ICR MS. The major emphasis was put upon the study on the O2 class species (petroleum carboxylic acids). The test results revealed that aliphatic acids and monocyclic naphthenic acids accounted for a large proportion in petroleum carboxylic acids of the Dar crude. The relative abundance of aliphatic acids and monocyclic naphthenic acids decreased with an increasing boiling point of fractions. Meanwhile, the relative abundance of bicyclic and tricyclic naphthenic acids increased at first and then decreased, whereas the relative abundance of petroleum carboxylic acids with higher double-bond equivalence (DBE) values increased. The high abundance of aliphatic acids in the Dar crude and its fractions covered the carbon numbers in a range of 16 to 18 which had important geochemical signifi- cance. The O2 class species were distributed in a broad range of DBE values and carbon numbers with increasing boiling points of fractions.展开更多
A novel bromination of α,β-unsaturated carboxylic acids was developed via a decarboxylation by virtue of a direct anodic electro-oxidation.In this method,ammonium bromide was employed as a bromine source and the rea...A novel bromination of α,β-unsaturated carboxylic acids was developed via a decarboxylation by virtue of a direct anodic electro-oxidation.In this method,ammonium bromide was employed as a bromine source and the reaction features transition-metal-free,short time,and no additional supporting electrolyte.展开更多
The catalytic alcohol dehydrogenation to carboxylic acids has been demonstrated as an atom-economic and environmental-friendly synthetic method.However,the reported catalysts either require relatively complicated synt...The catalytic alcohol dehydrogenation to carboxylic acids has been demonstrated as an atom-economic and environmental-friendly synthetic method.However,the reported catalysts either require relatively complicated synthesis or exhibit high activity only in the presence of a solvent.Therefore,it is still in high demand to obtain catalysts that feature facile synthesis and perform well even without any solvent.Herein,a series of nanostructured bimetallic Zn/Co species embedded in N-doped hierarchical porous carbon were fabricated in a facile and green manner.More significantly,the best-performing material(Zn/Co@NC-800)was identified as the first heterogeneous catalyst to enable this transformation under solvent-free conditions.Moreover,the as-prepared composites were comprehensively investigated to de-termine their structural and morphological properties,which rationalized the superiority of Zn/Co@NC-800 over the other synthesized materials.Further studies signified that Co sites(both Co^(0)and Co^(2+))and N species(mainly pyridinic N)were probably involved in this process,functioning as the Lewis acid site and basic site,respectively.Hopefully,this study could provide a simple and sustainable method for carboxylic acid synthesis.展开更多
The use of chiral organophosphoras derivatizing agents prepared in situ from chiral tartrate or chiral diamine for the 31PNMR determination of the enantiomeric composition of chiral carboxylic acids is described. The ...The use of chiral organophosphoras derivatizing agents prepared in situ from chiral tartrate or chiral diamine for the 31PNMR determination of the enantiomeric composition of chiral carboxylic acids is described. The method is accurate, reliable and convenient.展开更多
A convenient and easy method is described for the formation of carboxamides from carboxylic acids and primary amines in solventless conditions using infrared (IR) light. Thus, under IR light, cinnamic acid derivatives...A convenient and easy method is described for the formation of carboxamides from carboxylic acids and primary amines in solventless conditions using infrared (IR) light. Thus, under IR light, cinnamic acid derivatives and amines can produce yields ranging from 50% to 85% of the resulting amide.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
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
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
Two manganese（II） coordination polymers, namely, {[Mn（PIP）（BIBP）]·（BIBP）0.5}n（1） and {[Mn（PTA）（BIMBP）（H2O）]·H2O（0.69）}n（2）（H2PIP = 5-（4-pyridyl）-isophthalic acid, H2 PTA =6-（4-pyridyl...Two manganese（II） coordination polymers, namely, {[Mn（PIP）（BIBP）]·（BIBP）0.5}n（1） and {[Mn（PTA）（BIMBP）（H2O）]·H2O（0.69）}n（2）（H2PIP = 5-（4-pyridyl）-isophthalic acid, H2 PTA =6-（4-pyridyl）-terephthalic acid, BIBP = 4,4？-bis（imidazol-1-yl）biphenyl, and BIMBP =4,4？-bis（imidazol-1-ylmethyl）biphenyl）, have been synthesized by using the bifunctional pyrinde-benzene carboxylic acids and bis（imidazole） linkers as mixed ligands to react with Mn SO4,and further characterized by elemental analysis, IR, and PXRD. Compound 1 is in the triclicnic system, space group P1 with a = 10.1089（8）, b = 13.1927（12）, c = 14.0638（12）A, α = 69.437（2）, β= 73.2890（10）, γ = 78.5320（10）o, V = 1671.9（2） A^3, Z = 2, Dc = 1.449 g/cm^3, F（000） = 705,μ（MoK α） = 0.453 mm^-1, S = 1.053, R = 0.0491 and wR = 0.1367 for 5837 unique reflections（Rint =0.0208） with I 〉 2σ（I）. Compound 2 belongs to the monoclicnic system, space group C2/c with a =15.199（3）, b = 19.731（3）, c = 21.537（5） ？, β = 105.228（3）o, V = 6232（2） A^3, Z = 8, Dc = 1.363g/cm^3, F（000） = 2648, μ（MoK α） = 0.475 mm^-1, S = 1.048, R = 0.0489 and wR = 0.1151 for 7414 unique reflections（Rint = 0.0425） with I 〉 2σ（I）. Structural analyses reveal that complex 1 is a4-connected（44.62）-sql bilayer structure with binuclear [Mn2（COO）2] SBU, while complex 2 is a normally（3,5）-connected（42.67.8）（42.6）-3,5L2 monolayer. And the sheets interacted with the adjacent sheets through weak interactions, finally giving a stable three-dimensional（3D）supramolecule. Besides, the variable-temperature magnetic susceptibility measurement of complex1 was investigated.展开更多
Nanometer calcium carbonate was modified with Frechet type polyether dendrons bearing a COOH group at thefocal point by a wet-coating technique in dichloromethane at room temperature. The interaction between CaCO;and ...Nanometer calcium carbonate was modified with Frechet type polyether dendrons bearing a COOH group at thefocal point by a wet-coating technique in dichloromethane at room temperature. The interaction between CaCO;and thedendritic modifier was proven by IR and mass spectroscopy of the modified CaCO;after thorough extraction withdichloromethane. The amount of tightly bonded organic modifier was estimated by TGA. It was shown that the amount ofbonded molecules decreased with increasing generation number due to the larger number of branches. Compared tounmodified CaCO;, the modified CaCO;possess different dispersibility in water and in organic solvents.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.
基金the Persian Gulf University Research Council for generous partial financial support of this study
文摘A mild,efficient and simple method for the preparation of acyl azides from carboxylic acids using chlorodiphenylphosphine in the presence of molecular iodine and sodium azide is described.
文摘The selective catalytic hydrogenation of carboxylic acids is an important process for alcohol production,while efficient heterogeneous catalyst systems are still being explored.Here,we report the selective hydrogenation of carboxylic acids using earth‐abundant cobalt oxides through a reaction‐controlled catalysis process.The further reaction of the alcohols is completely hindered by the presence of carboxylic acids in the reaction system.The partial reduction of cobalt oxides by hydrogen at designated temperatures can dramatically enhance the catalytic activity of pristine samples.A wide range of carboxylic acids with a variety of functional groups can be converted to the corresponding alcohols at a yield level applicable to large‐scale production.Cobalt monoxide was established as the preferred active phase for the selective hydrogenation of carboxylic acids.
文摘The potential energy difference of trivalent Pr/Nd complex ions with various α hydroxyl carboxylic acids were computed by molecular mechanics plus(MM +) model. Its relationships with the steric hindrance of the coordinating lignads and with the separation factor of Pr/Nd were discussed. It is found that the MM + model can be used for selecting and designing ligand as effective eluant, with which Pr 3+ and Nd 3+ can be separated by ion exchange chromatography.
基金the National Natural Science Foundation of China(Nos.82073973,81872969)the Jilin Provincial Industrial Innovation Special Fund Project(No.20200703015ZP)the Science and the Youth Innovation Promotion Association of CAS(No.2019227)。
文摘Aromatic carboxylic acids(ACAs)may be as transformed key metabolites via gut microbiome for playing better pharmacological effects.However,it's rare to achieve high-specificity,high-sensitivity,and highthroughput detection simultaneously,especially,for tracing trace ACAs in gut microbiome.In this work,firstly,a novel dual-template and double-shelled molecularly imprinted 96-well microplates(DDMIPs)was designed and amplified signal for p-hydroxybenzoic acid(PBA)and 3,4,5-trimethoxycinnamic acid(TMA).Additionally,the DDMIPs and a stable isotope labeling derivatization(SILD)method combined with the ultra-high performance liquid chromatography triple quadrupole tandem mass spectrometry(UHPLC-TQ MS)was firstly stepwise integrated,achieving high-effective,high-sensitive,and highthroughput study of gut microbiome metabolism.The whole strategy showed lower limits of detections(LODs)up to 1000 folds than the traditional method,and revealed a more real metabolism-time profile of PBA and TMA by 3-step signal amplification.The platform also laid the foundation for fast,simple,high-selective,high-effective,and high-throughput metabolism and pharmacological research.
文摘The Dar crude oil produced in Sudan was distilled into several fractions. The heteroatom class species in crude and its fractions were characterized by the negative-ion ESI FT-ICR MS. The major emphasis was put upon the study on the O2 class species (petroleum carboxylic acids). The test results revealed that aliphatic acids and monocyclic naphthenic acids accounted for a large proportion in petroleum carboxylic acids of the Dar crude. The relative abundance of aliphatic acids and monocyclic naphthenic acids decreased with an increasing boiling point of fractions. Meanwhile, the relative abundance of bicyclic and tricyclic naphthenic acids increased at first and then decreased, whereas the relative abundance of petroleum carboxylic acids with higher double-bond equivalence (DBE) values increased. The high abundance of aliphatic acids in the Dar crude and its fractions covered the carbon numbers in a range of 16 to 18 which had important geochemical signifi- cance. The O2 class species were distributed in a broad range of DBE values and carbon numbers with increasing boiling points of fractions.
基金the National Nature Science Foundation of China(Nos.21472177,21672200,21432009,J1310010)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB20000000)
文摘A novel bromination of α,β-unsaturated carboxylic acids was developed via a decarboxylation by virtue of a direct anodic electro-oxidation.In this method,ammonium bromide was employed as a bromine source and the reaction features transition-metal-free,short time,and no additional supporting electrolyte.
基金This work was financially supported by the Natural Science Foundation of Hubei Province(No.2022CFB388)the fund of the Key Laboratory of Catalysis and Energy Materials Chemistry of the Ministry of Education&Hubei Key Laboratory of Catalysis and Ma-terials Science(No.CHCL19002)+1 种基金the State Key Laboratory of Ad-vanced Technology for Materials Synthesis and Processing(Wuhan University of Technology,No.2021-KF-19)the National Natural Science Foundation of China(No.22102127).We would also like to thank eceshi(www.eceshi.com)for the TPD tests.
文摘The catalytic alcohol dehydrogenation to carboxylic acids has been demonstrated as an atom-economic and environmental-friendly synthetic method.However,the reported catalysts either require relatively complicated synthesis or exhibit high activity only in the presence of a solvent.Therefore,it is still in high demand to obtain catalysts that feature facile synthesis and perform well even without any solvent.Herein,a series of nanostructured bimetallic Zn/Co species embedded in N-doped hierarchical porous carbon were fabricated in a facile and green manner.More significantly,the best-performing material(Zn/Co@NC-800)was identified as the first heterogeneous catalyst to enable this transformation under solvent-free conditions.Moreover,the as-prepared composites were comprehensively investigated to de-termine their structural and morphological properties,which rationalized the superiority of Zn/Co@NC-800 over the other synthesized materials.Further studies signified that Co sites(both Co^(0)and Co^(2+))and N species(mainly pyridinic N)were probably involved in this process,functioning as the Lewis acid site and basic site,respectively.Hopefully,this study could provide a simple and sustainable method for carboxylic acid synthesis.
文摘The use of chiral organophosphoras derivatizing agents prepared in situ from chiral tartrate or chiral diamine for the 31PNMR determination of the enantiomeric composition of chiral carboxylic acids is described. The method is accurate, reliable and convenient.
基金PAPIIT/UNAM Projects No.IN200614 and IT202015 and project PIAPI VC02 for partially supporting this worka part of the Project Catedra:Diseno de Sustancias Bioactivas of FESC-UNAM-2012.
文摘A convenient and easy method is described for the formation of carboxamides from carboxylic acids and primary amines in solventless conditions using infrared (IR) light. Thus, under IR light, cinnamic acid derivatives and amines can produce yields ranging from 50% to 85% of the resulting amide.
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.
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 NSF of Fujian Province(2015J01597)Collegiate Natural Science Fund of Fujian Province(JK2012019)Professor Fund of Fujian Medical University(JS14008)
文摘Two manganese（II） coordination polymers, namely, {[Mn（PIP）（BIBP）]·（BIBP）0.5}n（1） and {[Mn（PTA）（BIMBP）（H2O）]·H2O（0.69）}n（2）（H2PIP = 5-（4-pyridyl）-isophthalic acid, H2 PTA =6-（4-pyridyl）-terephthalic acid, BIBP = 4,4？-bis（imidazol-1-yl）biphenyl, and BIMBP =4,4？-bis（imidazol-1-ylmethyl）biphenyl）, have been synthesized by using the bifunctional pyrinde-benzene carboxylic acids and bis（imidazole） linkers as mixed ligands to react with Mn SO4,and further characterized by elemental analysis, IR, and PXRD. Compound 1 is in the triclicnic system, space group P1 with a = 10.1089（8）, b = 13.1927（12）, c = 14.0638（12）A, α = 69.437（2）, β= 73.2890（10）, γ = 78.5320（10）o, V = 1671.9（2） A^3, Z = 2, Dc = 1.449 g/cm^3, F（000） = 705,μ（MoK α） = 0.453 mm^-1, S = 1.053, R = 0.0491 and wR = 0.1367 for 5837 unique reflections（Rint =0.0208） with I 〉 2σ（I）. Compound 2 belongs to the monoclicnic system, space group C2/c with a =15.199（3）, b = 19.731（3）, c = 21.537（5） ？, β = 105.228（3）o, V = 6232（2） A^3, Z = 8, Dc = 1.363g/cm^3, F（000） = 2648, μ（MoK α） = 0.475 mm^-1, S = 1.048, R = 0.0489 and wR = 0.1151 for 7414 unique reflections（Rint = 0.0425） with I 〉 2σ（I）. Structural analyses reveal that complex 1 is a4-connected（44.62）-sql bilayer structure with binuclear [Mn2（COO）2] SBU, while complex 2 is a normally（3,5）-connected（42.67.8）（42.6）-3,5L2 monolayer. And the sheets interacted with the adjacent sheets through weak interactions, finally giving a stable three-dimensional（3D）supramolecule. Besides, the variable-temperature magnetic susceptibility measurement of complex1 was investigated.
基金This work was supported by Tsinghua-Zhongda Postdoctoral Science Foundation and China Postdoctoral Science Foundation.
文摘Nanometer calcium carbonate was modified with Frechet type polyether dendrons bearing a COOH group at thefocal point by a wet-coating technique in dichloromethane at room temperature. The interaction between CaCO;and thedendritic modifier was proven by IR and mass spectroscopy of the modified CaCO;after thorough extraction withdichloromethane. The amount of tightly bonded organic modifier was estimated by TGA. It was shown that the amount ofbonded molecules decreased with increasing generation number due to the larger number of branches. Compared tounmodified CaCO;, the modified CaCO;possess different dispersibility in water and in organic solvents.
