The present study was designed to isolate and characterize novel chemical constituents of the stem bark of Juglans mandshurica Maxim.(Juglandaceae).The chemical constituents were isolated and purified by various chrom...The present study was designed to isolate and characterize novel chemical constituents of the stem bark of Juglans mandshurica Maxim.(Juglandaceae).The chemical constituents were isolated and purified by various chromatographic techniques. The structures of the compounds were elucidated on the basis of spectral data(1D and 2D NMR, HR-ESI-MS, CD, UV, and IR) and by the comparisons of spectroscopic data with the reported values in the literatures. Two long chain polyunsaturated fatty acids(1 and 2) were obtained and identified as(S)-(8E,10E)-12-hydroxy-7-oxo-8,10-octadecadienoic acid(1) and(S)-(8E, 10E)-12-hydroxy-7-oxo-8,10-octadecadienoic acid methyl ester(2). To the best of our knowledge, this is the first report on the isolation and structural elucidation of the two new conjugated ketonic fatty acids from this genus.展开更多
The combination of a low cost source of Biofine＇s levulinic acid with available way of valeric acid synthesis opens up new opportunities for valeric acid as a promising bio-derived source for synthesis of valuable co...The combination of a low cost source of Biofine＇s levulinic acid with available way of valeric acid synthesis opens up new opportunities for valeric acid as a promising bio-derived source for synthesis of valuable compounds for transportation sector. The present review illustrates the development of different approaches to one–pot synthesis of fuel-like alkanes from lignocellulose derived carboxylic acids where particular focus is given to valeric acid consecutive decarboxylative coupling（ketonization） and ketone hydrodeoxygenation in a single reactor over one catalyst bed. The key factors that influence the catalytic performance on both ketonization and hydrodeoxygenation steps as well as their cross-influence will be clarified to provide insights for the design of more efficient catalysts for the one-pot transformation. Valeric acid is considered as a potential acid source from viewpoint of cost effectiveness and feasibility of such transformation with reasonable alkane yield. The both reaction mechanisms and kinetics will also be discussed to understand deeply how the selective C–C coupling and following C=O hydrogenation can be achieved.展开更多
α-Trifluoromethyl ketones are a class of useful compounds with versatile applications.Their synthetic application via the transformation of the C—F bonds is of particular interest by allowing the synthesis of organi...α-Trifluoromethyl ketones are a class of useful compounds with versatile applications.Their synthetic application via the transformation of the C—F bonds is of particular interest by allowing the synthesis of organic compounds with diverse structures.Herein,the advances in the research areas ofα-trifluoromethyl ketone synthesis and their defluorination reactions are reviewed.Discussion on the mechanisms of the typical reactions has also been provided,in hope of affording some guides to the chemistry ofα-trifluoromethyl ketones in the synthetic methods toward themselves and their derivatives.展开更多
The selective hydrogenation ofα,β-unsaturated aldehydes/ketones enables precise control over product structures and properties by regulating hydrogen transport pathways and bond cleavage sequences to selectively red...The selective hydrogenation ofα,β-unsaturated aldehydes/ketones enables precise control over product structures and properties by regulating hydrogen transport pathways and bond cleavage sequences to selectively reduce C=C or C=O bonds while preserving other functional groups within the molecule.This approach serves as a critical strategy for the directional synthesis of high-value molecules.However,achieving such selectivity remains challenging due to the thermodynamic equilibrium and kinetic competition between C=O and C=C bonds inα,β-unsaturated systems.Consequently,constructing precisely targeted catalytic systems is essential to overcome these limitations,offering both fundamental scientific significance and industrial application potential.Metal-organic frameworks(MOFs)and their derivatives have emerged as innovative platforms for designing such systems,owing to their programmable topology,tunable pore microenvironments,spatially controllable active sites,and modifiable electronic structures.This review systematically summarizes the research progress of MOF-based catalysts for selec-tive hydrogenation ofα,β-unsaturated aldehydes/ketones in the last decade,with emphasis on the design strategy,conformational relationship,and catalytic mechanism,aiming to provide new ideas for the design of targeted catalyt-ic systems for the selective hydrogenation ofα,β-unsaturated aldehydes/ketones.展开更多
Employing the principle of active moiety concatenation, a novel series of symmetrical triazine compounds were designed. A series of novel triazine compounds were synthesized using cyanuric chloride, amines, and chalco...Employing the principle of active moiety concatenation, a novel series of symmetrical triazine compounds were designed. A series of novel triazine compounds were synthesized using cyanuric chloride, amines, and chalcones as the initial reactants. The structures of these compounds were characterized through FT-IR, 1H-NMR, 13C-NMR, high-resolution mass spectrometry (HRMS) and high performance liquid chromatography (HPLC). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetra- zolium bromide (MTT) assay was employed to evaluate the in vitro anti-proliferative activity of the new s-triazine compounds against human lung cancer cells (A549), human cervical cancer cells (HeLa), human breast cancer cells (MCF-7) and human colon cancer cells (SW620). The findings indicated that several compounds exhibited promising antitumor effects. Notably, (E)-1-(4-((4,6-dimorpholino-1,3,5-triazin-2-yl)oxy)phenyl)-3-(thiophen-2-yl)prop-2-en-1-one (3bg) demonstrated efficacy as a broad-spectrum anticancer agent, exhibiting significant activity against the A549, HeLa, and MCF-7 cell lines. Furthermore, (E)-1-(4-((4,6-dimorpholino-1,3,5-triazin-2-yl)oxy)phenyl)-3-phenylprop-2-en-1-one (3bb) displayed the most potent in vitro antitumor activity against the MCF-7 cell line with an IC_(50) value of 16.4 μmol/L, establishing it as the most active compound in assay.展开更多
A direct Michael addition reaction between imidazo[1,2-a]pyridines andα,β-unsaturated ketones using acidic alumina as a C(sp3)—H acid catalyst has been developed.The abundant C(sp3)—H acid sites(Al^(3+))on the aci...A direct Michael addition reaction between imidazo[1,2-a]pyridines andα,β-unsaturated ketones using acidic alumina as a C(sp3)—H acid catalyst has been developed.The abundant C(sp3)—H acid sites(Al^(3+))on the acidic alumina surface effectively activate the carbonyl group ofα,β-unsaturated ketones,significantly enhancing the electrophilicity of theβ-carbon and thereby facilitating selective alkylation at the C3 position of imidazo[1,2-a]pyridines.This method demonstrates excellent functional group compatibility,mild reaction conditions,low reagent costs,and operational simplicity,providing a novel strategy for the efficient synthesis of alkylated imidazo[1,2-a]pyridine derivatives.展开更多
Objective Hypoxia plays a critical role in the pathophysiology of cardiomyopathy,myocardial infarction,and heart failure.Promoting ketone metabolism has been shown to be beneficial for myocardial cells under hypoxic c...Objective Hypoxia plays a critical role in the pathophysiology of cardiomyopathy,myocardial infarction,and heart failure.Promoting ketone metabolism has been shown to be beneficial for myocardial cells under hypoxic conditions.However,the expression and regulatory mechanisms of key enzymes in the ketone pathway under hypoxic conditions are still unclear.This study aimed to investigate the effects of hypoxia on the expression of key enzymes in the ketone metabolic pathway and the underlying regulatory mechanisms involved.Methods H9C2 myocardial cells were cultured for 6 h in an oxygen-glucose-deprived state,and the expression of various genes was detected by quantitative real-time PCR.ELISA and lactate dehydrogenase(LDH)cytotoxicity assay were used to measure CoAs,itaconic acid,and LDH levels,respectively,and the dependence of gene expression on hypoxia-inducible factor-1 alpha(HIF-1α)was evaluated using the inhibitor LW6.Results H9C2 cardiomyocytes exhibited increased ketone body metabolism in response to hypoxia.Hypoxia induced the expression of the ketone body enzymes succinyl-CoA:3-oxoacid CoA transferase(SCOT/OXCT1),3-hydroxybutyrate dehy-drogenase 2(BDH2),and acyl-CoA:cholesterol acyltransferase 1(ACAT1)in cardiomyocytes,with a concomitant increase in the level of acyl-CoA and a decrease in the level of succinyl-CoA.The HIF-1αinhibitor LW6 could partially reverse the expression of BDH2 and ACAT1,as well as the levels of succinyl-CoA.Interestingly,however,hypoxia-induced SCOT/OXCT1 expression was not regulated by the HIF-1αinhibitor.In addition,hypoxia promoted the expression of inflamma-tory factors.Conclusion These data confirm the critical role of ketone metabolism in myocardial hypoxia and help to elucidate the patho-physiology of cardiomyopathy,myocardial infarction and heart failure.展开更多
C-C coupling and hydrodeoxygenation are two important reactions in the production of sustainable aviation fuels(SAFs)with lignocellulose derived oxygenates.However,it is challenging to integrate them into a one-step p...C-C coupling and hydrodeoxygenation are two important reactions in the production of sustainable aviation fuels(SAFs)with lignocellulose derived oxygenates.However,it is challenging to integrate them into a one-step process because the necessity of oxygen containing functional groups in the C-C coupling reactions.Herein,jet fuel range polycycloalkanes and branched alkanes were directly synthesized by a cascade self-aldol condensation/hydrodeoxygenation reaction of lignocellulosic ketones over a zirconium phosphate loaded calcium modified nickel catalyst(NiCa/ZrP)that was prepared by a simple incipient impregnation method.Compared with the catalyst systems that have been reported in literature,the NiCa/ZrP catalyst have many advantages such as fewer step,easier operation and preparation,lower equipment investment and cost,wider applicability,etc.Moreover,the NiCa/ZrP is also applicable for the direct production of jet fuel range alkanes with lignocellulosic ketones and/or alcohols by a cascade dehydrogenation/aldol condensation/hydrodeoxygenation reaction.This work gives a new idea about the reduction of energy consumption and cost by catalyst designing in the manufacture of SAFs from lignocellulose.展开更多
The dynamic kinetic resolution(DKR)process remains a highly efficacious approach for constructing chiral amino alcohols via the catalytic asymmetric hydrogenation ofα-amino ketones.We report herein a highly efficient...The dynamic kinetic resolution(DKR)process remains a highly efficacious approach for constructing chiral amino alcohols via the catalytic asymmetric hydrogenation ofα-amino ketones.We report herein a highly efficient and enantioselective anti-selective dynamic kinetic asymmetric hydrogenation ofα-amino ketones catalyzed by Ir-(S)-f-phamidol system,providing various chiral amino alcohols and chiral oxazolidin-2-ones divergently with high diastereo-and enantioselectivity(up to 99%yield,up to 99%ee and up to 99:1 dr).In addition,the reaction could be performed on the gram-scale,and the resulting chiral amino alcohols are key intermediates of norephedrine and metaraminol.展开更多
Unsaturated alcohols are a class of Biogenic volatile organic compounds(BVOCs)emitted in large quantities by plants when damaged or under adverse environmental conditions,and studies on their atmospheric degradation a...Unsaturated alcohols are a class of Biogenic volatile organic compounds(BVOCs)emitted in large quantities by plants when damaged or under adverse environmental conditions,and studies on their atmospheric degradation at night are still lacking.We used chamber experiments to study the gas-phase reactions of three unsaturated alcohols,E-2-penten-1-ol,Z-2-hexen-1-ol and Z-3-hepten-1-ol,with NO_(3)radicals(NO_(3)•)during the night.The rate constants of these reactions were(11.7±1.76)×10^(−13),(8.55±1.33)×10^(−13)and(6.08±0.47)×10^(−13)cm^(3)/(molecule·s)at 298K and 760 Torr,respectively.In contrast,the reaction rate of similar substances with ozone was about 10^(−18)cm^(3)/(molecule·s),which indicates that the reaction with NO_(3)•is themain oxidation pathway for unsaturated alcohols at night.Small molecule aldehydes and ketones were the main gas-phase organic products of the reaction of three aldehydes and ketones with NO_(3)•,and the total small molecule aldehydes and ketones yields can reach between 45%-60%.They mainly originate from the breakage of alkoxy radicals,and different breakage sites determine different product distributions.In addition,the SOA yields of the three unsaturated alcohols with NO_(3)•were 7.1%±1.0%,12.5%±1.9%and 30.0%±4.5%,respectively,whichweremuch higher than those of similarly structured substances with O_(3)or OH radicals(•OH).The results of high-resolution mass spectrometry shows that the main components of Secondary organic aerosol(SOA)of the three unsaturated alcohols are dimeric compounds containing several nitrate groups,which are formed through the polymerization of oxyalkyl radicals.展开更多
Pyridyl-based ketones and 1,6-diketones are both attractive and invaluable scaffolds which play pivotal roles in the construction and structural modification of a plethora of synthetically paramount natural products,p...Pyridyl-based ketones and 1,6-diketones are both attractive and invaluable scaffolds which play pivotal roles in the construction and structural modification of a plethora of synthetically paramount natural products,pharmaceuticals,organic materials and fine chemicals.In this context,we herein demonstrate an unprecedented,robust and generally applicable synthetically strategy to deliver these two crucial ketone frameworks via visible-light-induced ring-opening coupling reactions of cycloalcohols with vinylazaarenes and enones,respectively.A plausible mechanism involves the selectiveβ-C-C bond cleavage of cycloalcohols enabled by proton-coupled electron transfer and ensuing Giese-type addition followed by single electron reduction and protonation.The synthetic methodology exhibits broad substrate scope,excellent functional group compatibility as well as operational simplicity and environmental friendliness.展开更多
The bioinert nature of polyether ether ketone(PEEK)material limits the widespread clinical application of PEEK implants.Although the porous structure is considered to improve osseointegration of PEEK implants,it is ha...The bioinert nature of polyether ether ketone(PEEK)material limits the widespread clinical application of PEEK implants.Although the porous structure is considered to improve osseointegration of PEEK implants,it is hardly used due to its mechanical properties.This study investigated the combined influence of the porous structure and in vivo mechanical stimulation on implantation safety and bone growth based on finite element analysis of the biomechanical behavior of the implantation system.The combined control of pore size and screw preloads allows the porous PEEK implant to achieve good osseointegration while maintaining a relatively high safety level.A pore size of 600μm and a preload of 0.05 N·m are the optimal combination for the long-term stability of the implant,with which the safety factor of the implant is>2,and the predicted percentage of effective bone growth area of the bone-implant interface reaches 97%.For further clinical application,PEEK implants were fabricated with fused filament fabrication(FFF)three-dimensional(3D)printing,and clinical outcomes demonstrated better bone repair efficacy and long-term stability of porous PEEK implants compared to solid PEEK implants.Moreover,good osteointegration performance of 3D-printed porous PEEK implants was observed,with an average bone volume fraction>40%three months after implantation.In conclusion,3D-printed porous PEEK implants have great potential for clinical application,with validated implantation safety and good osseointegration.展开更多
A novel process for the separation of hafnium from thiocyanic acid medium using the mixture of diisobutyl ketone（DIBK） and tributyl phosphate（TBP） as the extractant was developed.This extraction process was invest...A novel process for the separation of hafnium from thiocyanic acid medium using the mixture of diisobutyl ketone（DIBK） and tributyl phosphate（TBP） as the extractant was developed.This extraction process was investigated experimentally as a function of the amount of TBP added,acidity,zirconium and hafnium concentrations,salting-out agent,temperature,duration,respectively.The results show that hafnium is enriched in the organic layer and zirconium is in aqueous layer in DIBK-TBP system.Under the optimal technological conditions：TBP addition 20%（v/v）,aqueous phase acidity 3.0 mol/L,ammonium sulfate addition 0.8-1.25 mol/L,room temperature and extraction time 10 min,the separation factor of hafnium from zirconium is 9.3.展开更多
During the synthesis of the derivatives of styryl ketonic Mannich bases, a side -product IM,other than the normal Mannich base MA, is obtained. Mannich reaction is further studied and the formation mechanism of produc...During the synthesis of the derivatives of styryl ketonic Mannich bases, a side -product IM,other than the normal Mannich base MA, is obtained. Mannich reaction is further studied and the formation mechanism of product IM is postulated and discussed on the basis of deuterium labelling.展开更多
Macrocyclic arylene ether ketone was characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrum(MALDI-TOF MS)combining with nuclear magnetic resonance(NMR)spectra.No any more fragment io...Macrocyclic arylene ether ketone was characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrum(MALDI-TOF MS)combining with nuclear magnetic resonance(NMR)spectra.No any more fragment ionization peaks except for the molecular ion peak from the mass spectrum.The structure of macrocyclic dimmer was further affirmed by the NMR spectra through the analysis of chemical shifts.The MALDI-TOF MS combining with NMR technique was found an important tool to characterized Macrocyclic aromatic oligomers.展开更多
Novel reusable MnOx‐N@C catalyst has been developed for the direct oxidation of N‐heterocycles under solvent‐free conditions using TBHP as benign oxidant to give the corresponding N‐heterocyclic ketones. The catal...Novel reusable MnOx‐N@C catalyst has been developed for the direct oxidation of N‐heterocycles under solvent‐free conditions using TBHP as benign oxidant to give the corresponding N‐heterocyclic ketones. The catalytic system exhibited a broad substrate scope and excellent regi‐oselectivity, as well as being amenable to gram‐scale synthesis. This MnOx‐N@C catalyst also showed good reusability and was successfully recycled six times without any significant loss of activity.展开更多
The equilibrium and kinetics of methyl isobutyl ketone(MIBK) extraction resin for adsorption and separation of zirconium and hafnium were studied under the different conditions of acidity,initial total concentrations ...The equilibrium and kinetics of methyl isobutyl ketone(MIBK) extraction resin for adsorption and separation of zirconium and hafnium were studied under the different conditions of acidity,initial total concentrations of zirconium and hafnium and temperature.The equilibrium data of both zirconium and hafnium are found to follow the Freundlich adsorption isotherm,and the Freundlich isotherm constants(KF) are 3.53 and 0.64 mg/g,respectively.The equilibrium data of zirconium also fit the Langmuir adsorption isotherm,and the saturation adsorption capacity(Qmax) and the Langmuir isotherm constant(KL)are 75.93 mg/g and-0.012 7 L/g,respectively.The obtained kinetic data of both zirconium and hafnium are found to fit the HO pseudo-second-order kinetic model,and the rate constants of pseudo-second-order equation(k2) are-0.019 and 0.41 g/(mg·min),respectively.Column tests show that the MIBK extraction resin could be used as efficient adsorbent material for separating hafnium from zirconium.展开更多
Di(4-bromophenyl)ketone and various aromatic diamines as the monomers,a series of novel poly(imino ketone)s (PIKs)have been synthesized via palladium-catalyzed aryl amination,which is Hartwig-Buchwald polycondensation...Di(4-bromophenyl)ketone and various aromatic diamines as the monomers,a series of novel poly(imino ketone)s (PIKs)have been synthesized via palladium-catalyzed aryl amination,which is Hartwig-Buchwald polycondensation reaction.The structures of PIKs are characterized by means of elemental analysis,FT-IR,~1H-NMR and UV-Vis spectroscopy. The results show a good agreement with the proposed structure.The general properties of PIKs are studied by DSC,TG and wide-angle X-ray diffraction,the solubility behavior is...展开更多
Peptidyl epoxyketones were potential antitumor agents due to their 20S proteasome inhibitory activities. Based on their structures and special inhibitory mechanism, a series of compounds were designed by linking the e...Peptidyl epoxyketones were potential antitumor agents due to their 20S proteasome inhibitory activities. Based on their structures and special inhibitory mechanism, a series of compounds were designed by linking the epoxyketone moiety （the Cterminal pharmacophore） and the peptide backbones. To make these compounds, we used a novel method to prepare the terminal α,β-unsaturated ketone, the crucial intermediate, from Weinreb amide with satisfactory yield （62%-65%）.展开更多
基金supported by the National Natural Science Foundation of China(Nos.81160386,81260474,30911140276)
文摘The present study was designed to isolate and characterize novel chemical constituents of the stem bark of Juglans mandshurica Maxim.(Juglandaceae).The chemical constituents were isolated and purified by various chromatographic techniques. The structures of the compounds were elucidated on the basis of spectral data(1D and 2D NMR, HR-ESI-MS, CD, UV, and IR) and by the comparisons of spectroscopic data with the reported values in the literatures. Two long chain polyunsaturated fatty acids(1 and 2) were obtained and identified as(S)-(8E,10E)-12-hydroxy-7-oxo-8,10-octadecadienoic acid(1) and(S)-(8E, 10E)-12-hydroxy-7-oxo-8,10-octadecadienoic acid methyl ester(2). To the best of our knowledge, this is the first report on the isolation and structural elucidation of the two new conjugated ketonic fatty acids from this genus.
基金partly supported by Russian Academy of Science Project No. V.46.4.4Part of work related to metal oxides was supported by RFBR grant 15-03-09329
文摘The combination of a low cost source of Biofine＇s levulinic acid with available way of valeric acid synthesis opens up new opportunities for valeric acid as a promising bio-derived source for synthesis of valuable compounds for transportation sector. The present review illustrates the development of different approaches to one–pot synthesis of fuel-like alkanes from lignocellulose derived carboxylic acids where particular focus is given to valeric acid consecutive decarboxylative coupling（ketonization） and ketone hydrodeoxygenation in a single reactor over one catalyst bed. The key factors that influence the catalytic performance on both ketonization and hydrodeoxygenation steps as well as their cross-influence will be clarified to provide insights for the design of more efficient catalysts for the one-pot transformation. Valeric acid is considered as a potential acid source from viewpoint of cost effectiveness and feasibility of such transformation with reasonable alkane yield. The both reaction mechanisms and kinetics will also be discussed to understand deeply how the selective C–C coupling and following C=O hydrogenation can be achieved.
文摘α-Trifluoromethyl ketones are a class of useful compounds with versatile applications.Their synthetic application via the transformation of the C—F bonds is of particular interest by allowing the synthesis of organic compounds with diverse structures.Herein,the advances in the research areas ofα-trifluoromethyl ketone synthesis and their defluorination reactions are reviewed.Discussion on the mechanisms of the typical reactions has also been provided,in hope of affording some guides to the chemistry ofα-trifluoromethyl ketones in the synthetic methods toward themselves and their derivatives.
文摘The selective hydrogenation ofα,β-unsaturated aldehydes/ketones enables precise control over product structures and properties by regulating hydrogen transport pathways and bond cleavage sequences to selectively reduce C=C or C=O bonds while preserving other functional groups within the molecule.This approach serves as a critical strategy for the directional synthesis of high-value molecules.However,achieving such selectivity remains challenging due to the thermodynamic equilibrium and kinetic competition between C=O and C=C bonds inα,β-unsaturated systems.Consequently,constructing precisely targeted catalytic systems is essential to overcome these limitations,offering both fundamental scientific significance and industrial application potential.Metal-organic frameworks(MOFs)and their derivatives have emerged as innovative platforms for designing such systems,owing to their programmable topology,tunable pore microenvironments,spatially controllable active sites,and modifiable electronic structures.This review systematically summarizes the research progress of MOF-based catalysts for selec-tive hydrogenation ofα,β-unsaturated aldehydes/ketones in the last decade,with emphasis on the design strategy,conformational relationship,and catalytic mechanism,aiming to provide new ideas for the design of targeted catalyt-ic systems for the selective hydrogenation ofα,β-unsaturated aldehydes/ketones.
文摘Employing the principle of active moiety concatenation, a novel series of symmetrical triazine compounds were designed. A series of novel triazine compounds were synthesized using cyanuric chloride, amines, and chalcones as the initial reactants. The structures of these compounds were characterized through FT-IR, 1H-NMR, 13C-NMR, high-resolution mass spectrometry (HRMS) and high performance liquid chromatography (HPLC). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetra- zolium bromide (MTT) assay was employed to evaluate the in vitro anti-proliferative activity of the new s-triazine compounds against human lung cancer cells (A549), human cervical cancer cells (HeLa), human breast cancer cells (MCF-7) and human colon cancer cells (SW620). The findings indicated that several compounds exhibited promising antitumor effects. Notably, (E)-1-(4-((4,6-dimorpholino-1,3,5-triazin-2-yl)oxy)phenyl)-3-(thiophen-2-yl)prop-2-en-1-one (3bg) demonstrated efficacy as a broad-spectrum anticancer agent, exhibiting significant activity against the A549, HeLa, and MCF-7 cell lines. Furthermore, (E)-1-(4-((4,6-dimorpholino-1,3,5-triazin-2-yl)oxy)phenyl)-3-phenylprop-2-en-1-one (3bb) displayed the most potent in vitro antitumor activity against the MCF-7 cell line with an IC_(50) value of 16.4 μmol/L, establishing it as the most active compound in assay.
文摘A direct Michael addition reaction between imidazo[1,2-a]pyridines andα,β-unsaturated ketones using acidic alumina as a C(sp3)—H acid catalyst has been developed.The abundant C(sp3)—H acid sites(Al^(3+))on the acidic alumina surface effectively activate the carbonyl group ofα,β-unsaturated ketones,significantly enhancing the electrophilicity of theβ-carbon and thereby facilitating selective alkylation at the C3 position of imidazo[1,2-a]pyridines.This method demonstrates excellent functional group compatibility,mild reaction conditions,low reagent costs,and operational simplicity,providing a novel strategy for the efficient synthesis of alkylated imidazo[1,2-a]pyridine derivatives.
基金supported by the Specialized Research Fund for the National Natural Science Foundation of China(No.81973511).
文摘Objective Hypoxia plays a critical role in the pathophysiology of cardiomyopathy,myocardial infarction,and heart failure.Promoting ketone metabolism has been shown to be beneficial for myocardial cells under hypoxic conditions.However,the expression and regulatory mechanisms of key enzymes in the ketone pathway under hypoxic conditions are still unclear.This study aimed to investigate the effects of hypoxia on the expression of key enzymes in the ketone metabolic pathway and the underlying regulatory mechanisms involved.Methods H9C2 myocardial cells were cultured for 6 h in an oxygen-glucose-deprived state,and the expression of various genes was detected by quantitative real-time PCR.ELISA and lactate dehydrogenase(LDH)cytotoxicity assay were used to measure CoAs,itaconic acid,and LDH levels,respectively,and the dependence of gene expression on hypoxia-inducible factor-1 alpha(HIF-1α)was evaluated using the inhibitor LW6.Results H9C2 cardiomyocytes exhibited increased ketone body metabolism in response to hypoxia.Hypoxia induced the expression of the ketone body enzymes succinyl-CoA:3-oxoacid CoA transferase(SCOT/OXCT1),3-hydroxybutyrate dehy-drogenase 2(BDH2),and acyl-CoA:cholesterol acyltransferase 1(ACAT1)in cardiomyocytes,with a concomitant increase in the level of acyl-CoA and a decrease in the level of succinyl-CoA.The HIF-1αinhibitor LW6 could partially reverse the expression of BDH2 and ACAT1,as well as the levels of succinyl-CoA.Interestingly,however,hypoxia-induced SCOT/OXCT1 expression was not regulated by the HIF-1αinhibitor.In addition,hypoxia promoted the expression of inflamma-tory factors.Conclusion These data confirm the critical role of ketone metabolism in myocardial hypoxia and help to elucidate the patho-physiology of cardiomyopathy,myocardial infarction and heart failure.
基金supported by the National Key R&D Program of China(2022YFB4201802)the National Natural Science Foundation of China(22178335)DICP(DICP I202448)。
文摘C-C coupling and hydrodeoxygenation are two important reactions in the production of sustainable aviation fuels(SAFs)with lignocellulose derived oxygenates.However,it is challenging to integrate them into a one-step process because the necessity of oxygen containing functional groups in the C-C coupling reactions.Herein,jet fuel range polycycloalkanes and branched alkanes were directly synthesized by a cascade self-aldol condensation/hydrodeoxygenation reaction of lignocellulosic ketones over a zirconium phosphate loaded calcium modified nickel catalyst(NiCa/ZrP)that was prepared by a simple incipient impregnation method.Compared with the catalyst systems that have been reported in literature,the NiCa/ZrP catalyst have many advantages such as fewer step,easier operation and preparation,lower equipment investment and cost,wider applicability,etc.Moreover,the NiCa/ZrP is also applicable for the direct production of jet fuel range alkanes with lignocellulosic ketones and/or alcohols by a cascade dehydrogenation/aldol condensation/hydrodeoxygenation reaction.This work gives a new idea about the reduction of energy consumption and cost by catalyst designing in the manufacture of SAFs from lignocellulose.
基金the National Key R&D Program of China(No.2021YFA1500201)Shenzhen Science and Technology Innovation Committee(No.KQTD20150717103157174)+6 种基金Stable Support Plan Program of Shenzhen Natural Science Fund(No.20200925161222002)Key-Area Research and Development Program of Guangdong Province(No.2020B010188001)Innovative Team of Universities in Guangdong Province(No.2020KCXTD016)National Natural Science Foundation of China(No.21991113)the National Natural Science Foundation of China(Nos.21901107 and 22171129)the Guangdong Basic and Applied Basic Research Foundation(2022B1515020055)Shenzhen Science and Technology Innovation Committee(No.JCYJ20210324104202007)for financial support。
文摘The dynamic kinetic resolution(DKR)process remains a highly efficacious approach for constructing chiral amino alcohols via the catalytic asymmetric hydrogenation ofα-amino ketones.We report herein a highly efficient and enantioselective anti-selective dynamic kinetic asymmetric hydrogenation ofα-amino ketones catalyzed by Ir-(S)-f-phamidol system,providing various chiral amino alcohols and chiral oxazolidin-2-ones divergently with high diastereo-and enantioselectivity(up to 99%yield,up to 99%ee and up to 99:1 dr).In addition,the reaction could be performed on the gram-scale,and the resulting chiral amino alcohols are key intermediates of norephedrine and metaraminol.
基金supported by the National Key Research and Development Program of China(No.2020YFA0607800)the National Natural Science Foundation of China(Nos.42022039 and 42130606)Beijing National Laboratory for Molecular Sciences(No.BNLMS-CXXM-202011),the Youth Innovation Promotion Association of Chinese Academy of Sciences(No.Y2021013).
文摘Unsaturated alcohols are a class of Biogenic volatile organic compounds(BVOCs)emitted in large quantities by plants when damaged or under adverse environmental conditions,and studies on their atmospheric degradation at night are still lacking.We used chamber experiments to study the gas-phase reactions of three unsaturated alcohols,E-2-penten-1-ol,Z-2-hexen-1-ol and Z-3-hepten-1-ol,with NO_(3)radicals(NO_(3)•)during the night.The rate constants of these reactions were(11.7±1.76)×10^(−13),(8.55±1.33)×10^(−13)and(6.08±0.47)×10^(−13)cm^(3)/(molecule·s)at 298K and 760 Torr,respectively.In contrast,the reaction rate of similar substances with ozone was about 10^(−18)cm^(3)/(molecule·s),which indicates that the reaction with NO_(3)•is themain oxidation pathway for unsaturated alcohols at night.Small molecule aldehydes and ketones were the main gas-phase organic products of the reaction of three aldehydes and ketones with NO_(3)•,and the total small molecule aldehydes and ketones yields can reach between 45%-60%.They mainly originate from the breakage of alkoxy radicals,and different breakage sites determine different product distributions.In addition,the SOA yields of the three unsaturated alcohols with NO_(3)•were 7.1%±1.0%,12.5%±1.9%and 30.0%±4.5%,respectively,whichweremuch higher than those of similarly structured substances with O_(3)or OH radicals(•OH).The results of high-resolution mass spectrometry shows that the main components of Secondary organic aerosol(SOA)of the three unsaturated alcohols are dimeric compounds containing several nitrate groups,which are formed through the polymerization of oxyalkyl radicals.
基金financial support from National Natural Science Foundation of China(Nos.21801129,22078153 and22378201)National Key Research and Development Program of China(No.2022YFB3805603)+3 种基金Natural science research projects in Jiangsu Higher Education Institutions(No.18KJB150018)Open Research Fund of School of Chemistry and Chemical EngineeringHenan Normal University(No.2024Y16)Nanjing Tech University(Start-up Grant Nos.39837137,39837101 and 3827401739)for financial support。
文摘Pyridyl-based ketones and 1,6-diketones are both attractive and invaluable scaffolds which play pivotal roles in the construction and structural modification of a plethora of synthetically paramount natural products,pharmaceuticals,organic materials and fine chemicals.In this context,we herein demonstrate an unprecedented,robust and generally applicable synthetically strategy to deliver these two crucial ketone frameworks via visible-light-induced ring-opening coupling reactions of cycloalcohols with vinylazaarenes and enones,respectively.A plausible mechanism involves the selectiveβ-C-C bond cleavage of cycloalcohols enabled by proton-coupled electron transfer and ensuing Giese-type addition followed by single electron reduction and protonation.The synthetic methodology exhibits broad substrate scope,excellent functional group compatibility as well as operational simplicity and environmental friendliness.
基金supported by the National Key R&D Program of China(No.2023YFB4603500)the Program for Innovation Team of Shaanxi Province(No.2023-CX-TD-17)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Shaanxi Province Qinchuangyuan“Scientist+Engineer”Team Construction Project(No.2022KXJ-106).
文摘The bioinert nature of polyether ether ketone(PEEK)material limits the widespread clinical application of PEEK implants.Although the porous structure is considered to improve osseointegration of PEEK implants,it is hardly used due to its mechanical properties.This study investigated the combined influence of the porous structure and in vivo mechanical stimulation on implantation safety and bone growth based on finite element analysis of the biomechanical behavior of the implantation system.The combined control of pore size and screw preloads allows the porous PEEK implant to achieve good osseointegration while maintaining a relatively high safety level.A pore size of 600μm and a preload of 0.05 N·m are the optimal combination for the long-term stability of the implant,with which the safety factor of the implant is>2,and the predicted percentage of effective bone growth area of the bone-implant interface reaches 97%.For further clinical application,PEEK implants were fabricated with fused filament fabrication(FFF)three-dimensional(3D)printing,and clinical outcomes demonstrated better bone repair efficacy and long-term stability of porous PEEK implants compared to solid PEEK implants.Moreover,good osteointegration performance of 3D-printed porous PEEK implants was observed,with an average bone volume fraction>40%three months after implantation.In conclusion,3D-printed porous PEEK implants have great potential for clinical application,with validated implantation safety and good osseointegration.
基金Project (2012BAB10B10) supported by the National Key Technology R&D Program during the 12th Five-year Plan of ChinaProject (51174146) supported by the National Natural Science Foundation of China+2 种基金Project (212110) supported by the Foundation for Key Program of Ministry of Education,ChinaProject (Q20111509) supported by the Program for Excellent Talents of the Education Department of Hubei Province,ChinaProject (10125042) supported by the Scientific Research Foundation of Wuhan Institute of Technology,China
文摘A novel process for the separation of hafnium from thiocyanic acid medium using the mixture of diisobutyl ketone（DIBK） and tributyl phosphate（TBP） as the extractant was developed.This extraction process was investigated experimentally as a function of the amount of TBP added,acidity,zirconium and hafnium concentrations,salting-out agent,temperature,duration,respectively.The results show that hafnium is enriched in the organic layer and zirconium is in aqueous layer in DIBK-TBP system.Under the optimal technological conditions：TBP addition 20%（v/v）,aqueous phase acidity 3.0 mol/L,ammonium sulfate addition 0.8-1.25 mol/L,room temperature and extraction time 10 min,the separation factor of hafnium from zirconium is 9.3.
基金the National Natural Science Foundation of China.
文摘During the synthesis of the derivatives of styryl ketonic Mannich bases, a side -product IM,other than the normal Mannich base MA, is obtained. Mannich reaction is further studied and the formation mechanism of product IM is postulated and discussed on the basis of deuterium labelling.
文摘Macrocyclic arylene ether ketone was characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrum(MALDI-TOF MS)combining with nuclear magnetic resonance(NMR)spectra.No any more fragment ionization peaks except for the molecular ion peak from the mass spectrum.The structure of macrocyclic dimmer was further affirmed by the NMR spectra through the analysis of chemical shifts.The MALDI-TOF MS combining with NMR technique was found an important tool to characterized Macrocyclic aromatic oligomers.
基金supported by the National Basic research Program of China (973 Program,2009CB623505)the National Natural Science Foundation of China (21273225)~~
文摘Novel reusable MnOx‐N@C catalyst has been developed for the direct oxidation of N‐heterocycles under solvent‐free conditions using TBHP as benign oxidant to give the corresponding N‐heterocyclic ketones. The catalytic system exhibited a broad substrate scope and excellent regi‐oselectivity, as well as being amenable to gram‐scale synthesis. This MnOx‐N@C catalyst also showed good reusability and was successfully recycled six times without any significant loss of activity.
文摘The equilibrium and kinetics of methyl isobutyl ketone(MIBK) extraction resin for adsorption and separation of zirconium and hafnium were studied under the different conditions of acidity,initial total concentrations of zirconium and hafnium and temperature.The equilibrium data of both zirconium and hafnium are found to follow the Freundlich adsorption isotherm,and the Freundlich isotherm constants(KF) are 3.53 and 0.64 mg/g,respectively.The equilibrium data of zirconium also fit the Langmuir adsorption isotherm,and the saturation adsorption capacity(Qmax) and the Langmuir isotherm constant(KL)are 75.93 mg/g and-0.012 7 L/g,respectively.The obtained kinetic data of both zirconium and hafnium are found to fit the HO pseudo-second-order kinetic model,and the rate constants of pseudo-second-order equation(k2) are-0.019 and 0.41 g/(mg·min),respectively.Column tests show that the MIBK extraction resin could be used as efficient adsorbent material for separating hafnium from zirconium.
基金This work was financially supported by the National Natural Science Foundation of China(No.15076017).
文摘Di(4-bromophenyl)ketone and various aromatic diamines as the monomers,a series of novel poly(imino ketone)s (PIKs)have been synthesized via palladium-catalyzed aryl amination,which is Hartwig-Buchwald polycondensation reaction.The structures of PIKs are characterized by means of elemental analysis,FT-IR,~1H-NMR and UV-Vis spectroscopy. The results show a good agreement with the proposed structure.The general properties of PIKs are studied by DSC,TG and wide-angle X-ray diffraction,the solubility behavior is...
基金National Natural Science Foundation of China (Grant No. 30772650 and 20772008)
文摘Peptidyl epoxyketones were potential antitumor agents due to their 20S proteasome inhibitory activities. Based on their structures and special inhibitory mechanism, a series of compounds were designed by linking the epoxyketone moiety （the Cterminal pharmacophore） and the peptide backbones. To make these compounds, we used a novel method to prepare the terminal α,β-unsaturated ketone, the crucial intermediate, from Weinreb amide with satisfactory yield （62%-65%）.
