The work presents the synthesis and characterization of amidated pectin(AP) based polymer electrolyte membranes(PEM) crosslinked with glutaraldehyde(GA).The prepared membranes are characterized by Fourier transform in...The work presents the synthesis and characterization of amidated pectin(AP) based polymer electrolyte membranes(PEM) crosslinked with glutaraldehyde(GA).The prepared membranes are characterized by Fourier transform infrared spectroscopy(FTIR),organic elemental analysis,X-ray diffraction studies(XRD),thermogravimetric analysis (TGA) and impedance spectroscopy.Mechanical properties of the membranes are evaluated by tensile tests.The degree of amidation(DA),molar and mass reaction yields(Y_M and K_N) are calcu...展开更多
Photocatalytic conversion of CO_(2) is pivotal for mitigating the global greenhouse effect and fostering sustainable energy development.Nowadays,polymeric carbon nitride(PCN)has gained widespread application in CO_(2)...Photocatalytic conversion of CO_(2) is pivotal for mitigating the global greenhouse effect and fostering sustainable energy development.Nowadays,polymeric carbon nitride(PCN)has gained widespread application in CO_(2) solar reduction due to its excellent visible light response,suitable conduction band position,and good cost-effectiveness.However,the amorphous nature and low conductivity of PCN limit its photocatalytic efficiency by leading to low carrier concentrations and facile electron–hole recombination during photocatalysis.Addressing this bottleneck,in this study,potassium-doped PCN(KPCN)/copper(Ⅱ)-complexed bipyridine hydroxyquinoline carboxylic acid(Cu(Ⅱ)(bpy)(H_(2)hqc))composite catalysts were synthesized through a multistep microwave heating process.In the composite,the formation of an S-scheme junction facilitates the enrichment of more negative electrons on the conduction band of KPCN via intermolecular electron–hole recombination between Cu(Ⅱ)(bpy)(H_(2)hqc)(CuPyQc)and KPCN,thereby promoting efficient photoreduction of CO_(2) to CO.Microwave heating enhances the amidation reaction between these two components,achieving the immobilization of homogeneous molecular catalysts and forming amidation chemical bonds that serve as key channels for the S-scheme charge transfer.This work not only presents a new PCN-based catalytic system for CO_(2) reduction applications,but also offers a novel microwave-practical approach for immobilizing homogeneous catalysts.展开更多
As a hydrogen storage material,both AlH_(3)and LiNH_(2)possess a high hydrogen capacity.However,the dehydrogenated AlH_(3)can hardly absorb hydrogen under normal conditions,while LiNH_(2)will generate NH_(3)rather tha...As a hydrogen storage material,both AlH_(3)and LiNH_(2)possess a high hydrogen capacity.However,the dehydrogenated AlH_(3)can hardly absorb hydrogen under normal conditions,while LiNH_(2)will generate NH_(3)rather than H_(2)upon decomposition.In this work,we report thatthe combination of AlH_(3)and LiNH_(2)through simple ball milling leads to partial reversibility of the AlH_(3)-LiNH_(2)system and the suppression of NH_(3)liberation.The negatively charged H^(δ-)in AlH_(3)will react with the positively charged H^(δ+)in LiNH_(2)through a redox reaction to form Li_(2)NH,AlN,and H_(2)at 120-170℃.After dehydrogenation at above 270℃,Li_(3)AlN_(2)is generated,which is crucial for the reversibility of this system.The more the Li3AlN2generated,the better the reversibility of this system.The dehydrogenation capacity of AlH_(3)+2LiNH_(2)at the third cycle(3.0 wt%)is higher than that of AlH_(3)+LiNH_(2)(1.2 wt%)due to the generation of more Li3AlN2.The role of AIH_(3)/Al in the AlH_(3)-LiNH_(2)system is to fix the nitrogen into the form of AIN and Li_(3)AlN_(2)and thus suppress the liberation of NH_(3).Therefore,the synergy of AlH_(3)and LiNH_(2)leads to the reversibility of the Li-Al-NH system and the suppression of NH_(3).展开更多
A trinuclear copper complex [Cu_(3)(L2)_(2)(SO_(4))_(2)(H_(2)O)_(7)]·8H_(2)O(1)(HL2=1-hydroxy-3-(pyrazin-2-yl)-N-(pyrazin-2-ylmethyl)imidazo[1,5-a]pyrazine-8-carboxamide) with a multi-substituted imidazo[1,5-a]py...A trinuclear copper complex [Cu_(3)(L2)_(2)(SO_(4))_(2)(H_(2)O)_(7)]·8H_(2)O(1)(HL2=1-hydroxy-3-(pyrazin-2-yl)-N-(pyrazin-2-ylmethyl)imidazo[1,5-a]pyrazine-8-carboxamide) with a multi-substituted imidazo[1,5-a]pyrazine scaffold was serendipitously prepared from the reaction of the pro-ligand of H_(2)L1(N,N'-bis(pyrazin-2-ylmethyl)pyrazine-2,3-dicarboxamide) with CuSO_(4)·5H_(2O) in aqueous solution at room temperature.Complex 1 was characterized by IR,single-crystal X-ray analysis,and magnetic susceptibility measurements.Single-crystal X-ray analysis reveals that the complex consists of three Cu(Ⅱ) ions,two in situ transformed L2~-ligands,two coordinated sulfates,seven coordinated water molecules,and eight uncoordinated water molecules.Magnetic susceptibility measurement indicates that there are obvious ferromagnetic coupling interactions between the adjacent Cu(Ⅱ) ions in 1.CCDC:1852713.展开更多
The amide moiety plays an important role as a powerful bioactive backbone,and as the synthetic chemistry community moves toward more sp^(3)-rich scaffolds,alkyl halides have become the feedstock of choice for obtainin...The amide moiety plays an important role as a powerful bioactive backbone,and as the synthetic chemistry community moves toward more sp^(3)-rich scaffolds,alkyl halides have become the feedstock of choice for obtaining carbonylation products.With the development of photoredox catalysis,several aminocarbonylation systems for alkyl halides were developed which usually require transition metal catalysis.Considering the demands for green sustainable chemical synthesis,here we report a metal-free,exogenous catalyst-free aminocarbonylation reaction of alkyl iodides under atmospheric pressure of carbon monoxide.Through a combination of EDA and XAT strategies,the reaction occurs efficiently under only light irradiation at room temperature.展开更多
Carboxylic acid derivatives withα-quaternary carbon center are one of the most ubiquitous moieties in synthetic and medicinal chemistry.Hence,novel and efficient synthetic methods towards carboxylic acid derivatives ...Carboxylic acid derivatives withα-quaternary carbon center are one of the most ubiquitous moieties in synthetic and medicinal chemistry.Hence,novel and efficient synthetic methods towards carboxylic acid derivatives withα-quaternary carbon remain in high demand.However,most of the precursors of these complex compounds are not easy to prepare.Reported herein is a carbonylative five-component synthesis of amides and esters withα-quaternary carbon center enabled by palladium catalysis from abundant acrylonitrile,carbon monoxide,fluoroalkyl halides,and nucleophiles.Diverse amides and esters withα-quaternary carbon which contain difluoromethyl or perfluoroalkyl moiety were prepared in good to excellent yields,providing an efficient synthetic platform for sequential transformations.展开更多
The development of innovative and sustainable catalytic strategies for organic synthesis is a pivotal aspect of advancing material science and chemical engineering.This research presents a new catalytic method for the...The development of innovative and sustainable catalytic strategies for organic synthesis is a pivotal aspect of advancing material science and chemical engineering.This research presents a new catalytic method for the aminoacylation of N-sulfonyl ketimines by utilizing a potassium-doped graphite-like carbon nitride(g-C_(3)N_(4))framework.This method not only enhances the catalytic efficiency and broadens the light absorption spectrum of g-C_(3)N_(4)but also significantly reduces the recombination rate of electronhole pairs,thereby increasing the reaction yield and selectivity.Importantly,our approach facilitates the synthesis of aminoacylated N-heterocycles,expanding the applicability of potassium-modified g-C_(3)N_(4)in photocatalytic organic synthesis.A notable accomplishment of this study is the unprecedented generation of carbamoyl radicals via heterogeneous photocatalysis,which can be easily recycled after reaction.This advancement highlights the capability of potassium-doped g-C_(3)N_(4)(namely K-CN)as an advanced heterogeneous photocatalyst for the formation of complex organic compounds.展开更多
The safety and performance of lithium-ion batteries(LIBs)largely depend on the structural design and performance characteristics of the separator.Commercial polyolefin separators suffer from problems such as poor ther...The safety and performance of lithium-ion batteries(LIBs)largely depend on the structural design and performance characteristics of the separator.Commercial polyolefin separators suffer from problems such as poor thermal stability,insufficient porosity,and inferior electrolyte wettability,which not only easily lead to battery safety issues but also significantly affect the ionic conductivity and energy density of the batteries.Herein,we have designed a facile,efficient and controllable methodology to develop a high-porosity poly(m-phenylene isophthalamide)(PMIA)separator with both excellent wettability and superior thermal resistance by a vapor-induced phase separation technique.Specifically,the PMIA separator undergoes a thermal shrinkage of less than 1%even after being treated at 200℃ for one hour,which greatly enhances the thermal safety of the battery.In addition,a continuous and interconnected high-porosity structure(porosity of 69%)is formed by utilizing a stable and controllable solvent exchange rate,thereby constructing abundant channels for the transportation of ions within the battery.Moreover,the amide groups in the PMIA molecular structure further confer the separator with excellent wettability,enabling it to possess outstanding electrolyte absorption capacity(electrolyte absorption rate of 270%).As a result,the Li||LFP full cell with PMIA separator exhibits excellent capacity and cycling stability,maintaining a reversible specific capacity of 105.6 mAh g^(-1)after 600 cycles at 5 C.And Li||NCM811 full cell with PMIA separator show no significant degradation(168.1 mAh g^(-1)at 0.5 C)after long-cycle at high temperature.These results indicate the potential of the PMIA separator for high thermal stability and high energy battery,and the scalability of this technology also provides new ideas and directions for the preparation of separators with superior comprehensive performance.展开更多
A visible light-promoted fast photochemical Wolff rearrangement was developed toward synthesis ofα-substituted amides in continuous flow with the use of a photochemical oscillatory flow reactor(POFR).The control expe...A visible light-promoted fast photochemical Wolff rearrangement was developed toward synthesis ofα-substituted amides in continuous flow with the use of a photochemical oscillatory flow reactor(POFR).The control experiment indicates that a fast process of the Wolff rearrangement(<40 s)is involved.Notably,this protocol does not require excess use of any reactants,and the resultingα-substituted amides could be isolated by recrystallization in good to excellent yields.展开更多
Chiral N-substituted amino amides and esters are ubiquitous scaffolds in pesticides and pharmaceutical chemicals,but their asymmetric synthesis remains challenging especially for those with multiple chiral centers.In ...Chiral N-substituted amino amides and esters are ubiquitous scaffolds in pesticides and pharmaceutical chemicals,but their asymmetric synthesis remains challenging especially for those with multiple chiral centers.In this study,IR104 from Streptomyces aureocirculatus was identified from 157 wild-type imine reductases for the synthesis of(S)-2-((R)-2-oxo-4-propylpyrrolidin-1-yl)butanamide(antiepileptic drug Brivaracetam)via dynamic kinetic resolution reductive amination from ethyl 3-formylhexanoate and(S)-2-aminobutylamide with high diastereoselectivity.To further improve the catalytic efficiency of IR104,its mutant D191E/L195I/E253S/M258A(M3)was identified by saturation mutagenesis and iterative combinatorial mutagenesis,which exhibited a 102-fold increase in the catalytic efficiency relative to that of wild-type enzyme and high diastereoselectivity(98:2 d.r.).Crystal structural analysis and molecular dynamics simulations provided some insights into the molecular basis for the improved activity of the mutant enzyme.The imine reductase identified in this study could accept chiral amino amides/esters as amino donors for the dynamic kinetic resolution reductive amination of racemicα-substituted aldehydo-esters,expanding the substrate scope of imine reductases in the dynamic kinetic resolution-reductive amination.Finally,IR104-M3 was successfully used for the preparation of Brivaracetam at gram scale.Using this mutant,various N-substituted amino amides/esters with two chiral centers were also synthesized with up to 99:1 d.r.and 96%yields and subsequently converted intoγ-andδ-lactams,providing an efficient protocol for the synthesis of these important compounds via enzymatic dynamic kinetic resolution-reductive amination from simple building blocks.展开更多
A transition-metal-and oxidant-free amination/cyclization reaction to access 1,2,4-triazolo[1,5-a]pyridines was realized in water by using amino diphenylphosphinate as amino source.A broad array of readily accessible ...A transition-metal-and oxidant-free amination/cyclization reaction to access 1,2,4-triazolo[1,5-a]pyridines was realized in water by using amino diphenylphosphinate as amino source.A broad array of readily accessible N-(pyridyl)amides could be converted into the products featuring a diverse set of functional groups.The sustainable methodology was successfully applied to the late-stage functionalization of natural products and drugs.展开更多
Identifying chemical structures inhuman-derived samples presents significant challenges due to limited structural data obtained from untargeted metabolomics studies.When the chemical structures of molecules are closel...Identifying chemical structures inhuman-derived samples presents significant challenges due to limited structural data obtained from untargeted metabolomics studies.When the chemical structures of molecules are closely related to the phenotypic status of human ecosystems,it becomes invaluable to devise a method for efficiently and systematically determining structures that correlate with the pathophysiological status of humans in a high-throughput approach.展开更多
Aim To synthesize the tripepide Weinreb amide Boc Asp(OBzl) β Ala Asp(OBzl) N(OMe)Me (7) as a useful precursor of aspartyl peptide aldehyde derivatives; Methods DCC, IBCF method was used for preparation of ...Aim To synthesize the tripepide Weinreb amide Boc Asp(OBzl) β Ala Asp(OBzl) N(OMe)Me (7) as a useful precursor of aspartyl peptide aldehyde derivatives; Methods DCC, IBCF method was used for preparation of Weinreb amide; N hydroxysuccinimide activated ester was used in peptide synthesis; and Boc as N protecting group of amino acid. Results Boc Asp(OBzl) N(OMe)Me (3), Boc β Ala Asp(OBzl) N(OMe)Me (5), and Boc Asp(OBzl) β Ala Asp(OBzl) N(OMe)Me (7) were synthesized successfully. Conclusion An useful precursor of tripeptide aspartyl aldehydes was synthesized.展开更多
Five 1,4-dihydrothieno[3＇,2＇：5,6]thiopyrano[4,3-c]pyrazole-3-carboxylic amide derivatives were synthesized from 2- mercaptothiophene via a six-step procedure. The prepared compounds were initially evaluated for the...Five 1,4-dihydrothieno[3＇,2＇：5,6]thiopyrano[4,3-c]pyrazole-3-carboxylic amide derivatives were synthesized from 2- mercaptothiophene via a six-step procedure. The prepared compounds were initially evaluated for their antiprolifemtive activity using the estrogen receptors expressing MCF-7 human mammary tumor cell line in vitro. All of the prepared compounds showed moderate anti-tumor activity.展开更多
The amide A band of protein is sensitive to the hydrogen bands of amide groups of proteins. However, it is hard to distinguish the amide A band of aqueous protein in situ directly, since it overlaps with O-H stretchin...The amide A band of protein is sensitive to the hydrogen bands of amide groups of proteins. However, it is hard to distinguish the amide A band of aqueous protein in situ directly, since it overlaps with O-H stretching vibration of water. In this work, we presented a new analytical method of Raman ratio spectrum, which can extract the amide A band of proteins in water. To obtain the Raman ratio spectrum, the Raman spectrum of aqueous protein was divided by that of pure water. A mathematical simulation was employed to examine whether Raman ratio spectrum is effective. Two kinds of protein, lysozyme and （^-chymotrypsin were employed. The amide A bands of them in water were extracted from Raman ratio spectra. Additionally, the process of thermal denaturation of lysozyme was detected from Raman ratio spectrum. These results demonstrated the Raman ratio spectra could be employed to study the amide A modes of proteins in water.展开更多
文摘The work presents the synthesis and characterization of amidated pectin(AP) based polymer electrolyte membranes(PEM) crosslinked with glutaraldehyde(GA).The prepared membranes are characterized by Fourier transform infrared spectroscopy(FTIR),organic elemental analysis,X-ray diffraction studies(XRD),thermogravimetric analysis (TGA) and impedance spectroscopy.Mechanical properties of the membranes are evaluated by tensile tests.The degree of amidation(DA),molar and mass reaction yields(Y_M and K_N) are calcu...
基金supported by the National Natural Science Foundation of China(Nos.22106105 and 22201180)the Innovation Program of Shanghai Municipal Education Commission(No.2019-01-07-00-E00015)+2 种基金Shanghai Science and Technology Innovation Program(No.21DZ1206300)the Central Local Science and Technology Development Guidance Fund(No.YDZX20213100003002)Shanghai Science and Technology Commission Program(No.20060502200).
文摘Photocatalytic conversion of CO_(2) is pivotal for mitigating the global greenhouse effect and fostering sustainable energy development.Nowadays,polymeric carbon nitride(PCN)has gained widespread application in CO_(2) solar reduction due to its excellent visible light response,suitable conduction band position,and good cost-effectiveness.However,the amorphous nature and low conductivity of PCN limit its photocatalytic efficiency by leading to low carrier concentrations and facile electron–hole recombination during photocatalysis.Addressing this bottleneck,in this study,potassium-doped PCN(KPCN)/copper(Ⅱ)-complexed bipyridine hydroxyquinoline carboxylic acid(Cu(Ⅱ)(bpy)(H_(2)hqc))composite catalysts were synthesized through a multistep microwave heating process.In the composite,the formation of an S-scheme junction facilitates the enrichment of more negative electrons on the conduction band of KPCN via intermolecular electron–hole recombination between Cu(Ⅱ)(bpy)(H_(2)hqc)(CuPyQc)and KPCN,thereby promoting efficient photoreduction of CO_(2) to CO.Microwave heating enhances the amidation reaction between these two components,achieving the immobilization of homogeneous molecular catalysts and forming amidation chemical bonds that serve as key channels for the S-scheme charge transfer.This work not only presents a new PCN-based catalytic system for CO_(2) reduction applications,but also offers a novel microwave-practical approach for immobilizing homogeneous catalysts.
基金financially supported by the National Natural Science Foundation of China(Nos.22379030,52001079,52261038)the Science and Technology Department of Guangxi Zhuang Autonomous(Nos.2024JJG160001,GuiKeAD21238022)the Innovation Project of Guangxi Graduate Education(No.YCBZ2023011)
文摘As a hydrogen storage material,both AlH_(3)and LiNH_(2)possess a high hydrogen capacity.However,the dehydrogenated AlH_(3)can hardly absorb hydrogen under normal conditions,while LiNH_(2)will generate NH_(3)rather than H_(2)upon decomposition.In this work,we report thatthe combination of AlH_(3)and LiNH_(2)through simple ball milling leads to partial reversibility of the AlH_(3)-LiNH_(2)system and the suppression of NH_(3)liberation.The negatively charged H^(δ-)in AlH_(3)will react with the positively charged H^(δ+)in LiNH_(2)through a redox reaction to form Li_(2)NH,AlN,and H_(2)at 120-170℃.After dehydrogenation at above 270℃,Li_(3)AlN_(2)is generated,which is crucial for the reversibility of this system.The more the Li3AlN2generated,the better the reversibility of this system.The dehydrogenation capacity of AlH_(3)+2LiNH_(2)at the third cycle(3.0 wt%)is higher than that of AlH_(3)+LiNH_(2)(1.2 wt%)due to the generation of more Li3AlN2.The role of AIH_(3)/Al in the AlH_(3)-LiNH_(2)system is to fix the nitrogen into the form of AIN and Li_(3)AlN_(2)and thus suppress the liberation of NH_(3).Therefore,the synergy of AlH_(3)and LiNH_(2)leads to the reversibility of the Li-Al-NH system and the suppression of NH_(3).
文摘A trinuclear copper complex [Cu_(3)(L2)_(2)(SO_(4))_(2)(H_(2)O)_(7)]·8H_(2)O(1)(HL2=1-hydroxy-3-(pyrazin-2-yl)-N-(pyrazin-2-ylmethyl)imidazo[1,5-a]pyrazine-8-carboxamide) with a multi-substituted imidazo[1,5-a]pyrazine scaffold was serendipitously prepared from the reaction of the pro-ligand of H_(2)L1(N,N'-bis(pyrazin-2-ylmethyl)pyrazine-2,3-dicarboxamide) with CuSO_(4)·5H_(2O) in aqueous solution at room temperature.Complex 1 was characterized by IR,single-crystal X-ray analysis,and magnetic susceptibility measurements.Single-crystal X-ray analysis reveals that the complex consists of three Cu(Ⅱ) ions,two in situ transformed L2~-ligands,two coordinated sulfates,seven coordinated water molecules,and eight uncoordinated water molecules.Magnetic susceptibility measurement indicates that there are obvious ferromagnetic coupling interactions between the adjacent Cu(Ⅱ) ions in 1.CCDC:1852713.
基金supported by National Key R&D Program of China(No.2023YFA1507500)the International Partnership Program of Chinese Academy of Sciences(No.028GJHZ2023045FN)。
文摘The amide moiety plays an important role as a powerful bioactive backbone,and as the synthetic chemistry community moves toward more sp^(3)-rich scaffolds,alkyl halides have become the feedstock of choice for obtaining carbonylation products.With the development of photoredox catalysis,several aminocarbonylation systems for alkyl halides were developed which usually require transition metal catalysis.Considering the demands for green sustainable chemical synthesis,here we report a metal-free,exogenous catalyst-free aminocarbonylation reaction of alkyl iodides under atmospheric pressure of carbon monoxide.Through a combination of EDA and XAT strategies,the reaction occurs efficiently under only light irradiation at room temperature.
基金the financial support from National Key R&D Program of China(No.2023YFA1507500)DICP。
文摘Carboxylic acid derivatives withα-quaternary carbon center are one of the most ubiquitous moieties in synthetic and medicinal chemistry.Hence,novel and efficient synthetic methods towards carboxylic acid derivatives withα-quaternary carbon remain in high demand.However,most of the precursors of these complex compounds are not easy to prepare.Reported herein is a carbonylative five-component synthesis of amides and esters withα-quaternary carbon center enabled by palladium catalysis from abundant acrylonitrile,carbon monoxide,fluoroalkyl halides,and nucleophiles.Diverse amides and esters withα-quaternary carbon which contain difluoromethyl or perfluoroalkyl moiety were prepared in good to excellent yields,providing an efficient synthetic platform for sequential transformations.
基金financial support from the National Natural Science Foundation of China(No.22171249)the Science&Technology Innovation Talents in Universities of Henan Province(No.23HASTIT003)。
文摘The development of innovative and sustainable catalytic strategies for organic synthesis is a pivotal aspect of advancing material science and chemical engineering.This research presents a new catalytic method for the aminoacylation of N-sulfonyl ketimines by utilizing a potassium-doped graphite-like carbon nitride(g-C_(3)N_(4))framework.This method not only enhances the catalytic efficiency and broadens the light absorption spectrum of g-C_(3)N_(4)but also significantly reduces the recombination rate of electronhole pairs,thereby increasing the reaction yield and selectivity.Importantly,our approach facilitates the synthesis of aminoacylated N-heterocycles,expanding the applicability of potassium-modified g-C_(3)N_(4)in photocatalytic organic synthesis.A notable accomplishment of this study is the unprecedented generation of carbamoyl radicals via heterogeneous photocatalysis,which can be easily recycled after reaction.This advancement highlights the capability of potassium-doped g-C_(3)N_(4)(namely K-CN)as an advanced heterogeneous photocatalyst for the formation of complex organic compounds.
基金supported by the National Natural Science Foundation of China(52273059,52403046)the Science and Technology Plans of Tianjin(22JCYBJC01030)+1 种基金the Tianjin Research Innovation Project for Postgraduate Students(2022BKY145)partially supported by financial contributions from Yantai Tayho Advanced Materials Co.,Ltd。
文摘The safety and performance of lithium-ion batteries(LIBs)largely depend on the structural design and performance characteristics of the separator.Commercial polyolefin separators suffer from problems such as poor thermal stability,insufficient porosity,and inferior electrolyte wettability,which not only easily lead to battery safety issues but also significantly affect the ionic conductivity and energy density of the batteries.Herein,we have designed a facile,efficient and controllable methodology to develop a high-porosity poly(m-phenylene isophthalamide)(PMIA)separator with both excellent wettability and superior thermal resistance by a vapor-induced phase separation technique.Specifically,the PMIA separator undergoes a thermal shrinkage of less than 1%even after being treated at 200℃ for one hour,which greatly enhances the thermal safety of the battery.In addition,a continuous and interconnected high-porosity structure(porosity of 69%)is formed by utilizing a stable and controllable solvent exchange rate,thereby constructing abundant channels for the transportation of ions within the battery.Moreover,the amide groups in the PMIA molecular structure further confer the separator with excellent wettability,enabling it to possess outstanding electrolyte absorption capacity(electrolyte absorption rate of 270%).As a result,the Li||LFP full cell with PMIA separator exhibits excellent capacity and cycling stability,maintaining a reversible specific capacity of 105.6 mAh g^(-1)after 600 cycles at 5 C.And Li||NCM811 full cell with PMIA separator show no significant degradation(168.1 mAh g^(-1)at 0.5 C)after long-cycle at high temperature.These results indicate the potential of the PMIA separator for high thermal stability and high energy battery,and the scalability of this technology also provides new ideas and directions for the preparation of separators with superior comprehensive performance.
基金financial support from the National Natural Science Foundation of China(No.22208279)Financial support from the Fuzhou University(No.0041/511095)。
文摘A visible light-promoted fast photochemical Wolff rearrangement was developed toward synthesis ofα-substituted amides in continuous flow with the use of a photochemical oscillatory flow reactor(POFR).The control experiment indicates that a fast process of the Wolff rearrangement(<40 s)is involved.Notably,this protocol does not require excess use of any reactants,and the resultingα-substituted amides could be isolated by recrystallization in good to excellent yields.
文摘Chiral N-substituted amino amides and esters are ubiquitous scaffolds in pesticides and pharmaceutical chemicals,but their asymmetric synthesis remains challenging especially for those with multiple chiral centers.In this study,IR104 from Streptomyces aureocirculatus was identified from 157 wild-type imine reductases for the synthesis of(S)-2-((R)-2-oxo-4-propylpyrrolidin-1-yl)butanamide(antiepileptic drug Brivaracetam)via dynamic kinetic resolution reductive amination from ethyl 3-formylhexanoate and(S)-2-aminobutylamide with high diastereoselectivity.To further improve the catalytic efficiency of IR104,its mutant D191E/L195I/E253S/M258A(M3)was identified by saturation mutagenesis and iterative combinatorial mutagenesis,which exhibited a 102-fold increase in the catalytic efficiency relative to that of wild-type enzyme and high diastereoselectivity(98:2 d.r.).Crystal structural analysis and molecular dynamics simulations provided some insights into the molecular basis for the improved activity of the mutant enzyme.The imine reductase identified in this study could accept chiral amino amides/esters as amino donors for the dynamic kinetic resolution reductive amination of racemicα-substituted aldehydo-esters,expanding the substrate scope of imine reductases in the dynamic kinetic resolution-reductive amination.Finally,IR104-M3 was successfully used for the preparation of Brivaracetam at gram scale.Using this mutant,various N-substituted amino amides/esters with two chiral centers were also synthesized with up to 99:1 d.r.and 96%yields and subsequently converted intoγ-andδ-lactams,providing an efficient protocol for the synthesis of these important compounds via enzymatic dynamic kinetic resolution-reductive amination from simple building blocks.
基金financial support from the National Natural Science Foundation of China(No.82003585)the Program for Science&Technology Innovation Talents in Universities of Henan Province(No.24HASTIT069)+5 种基金the Technical Innovation Team of Henan Normal University(No.2022TD03)the Special Project for Fundamental Research in University of Henan Province(No.23ZX009)the Henan Science and Technology Program(No.232102310364)the Key Project of Henan Educational Committee(No.22A150041)Excellent Youth Foundation of Henan Scientific Committee(No.222300420012)the Young Core Instructor Training Program of Xinyang Agriculture and Forestry University(2023)。
文摘A transition-metal-and oxidant-free amination/cyclization reaction to access 1,2,4-triazolo[1,5-a]pyridines was realized in water by using amino diphenylphosphinate as amino source.A broad array of readily accessible N-(pyridyl)amides could be converted into the products featuring a diverse set of functional groups.The sustainable methodology was successfully applied to the late-stage functionalization of natural products and drugs.
基金supported by the National Natural Science Foundation of China(Nos.81930109 and 82321005)。
文摘Identifying chemical structures inhuman-derived samples presents significant challenges due to limited structural data obtained from untargeted metabolomics studies.When the chemical structures of molecules are closely related to the phenotypic status of human ecosystems,it becomes invaluable to devise a method for efficiently and systematically determining structures that correlate with the pathophysiological status of humans in a high-throughput approach.
文摘Aim To synthesize the tripepide Weinreb amide Boc Asp(OBzl) β Ala Asp(OBzl) N(OMe)Me (7) as a useful precursor of aspartyl peptide aldehyde derivatives; Methods DCC, IBCF method was used for preparation of Weinreb amide; N hydroxysuccinimide activated ester was used in peptide synthesis; and Boc as N protecting group of amino acid. Results Boc Asp(OBzl) N(OMe)Me (3), Boc β Ala Asp(OBzl) N(OMe)Me (5), and Boc Asp(OBzl) β Ala Asp(OBzl) N(OMe)Me (7) were synthesized successfully. Conclusion An useful precursor of tripeptide aspartyl aldehydes was synthesized.
基金National Natural Science Foundation of China (Grant No. 20474053)
文摘Five 1,4-dihydrothieno[3＇,2＇：5,6]thiopyrano[4,3-c]pyrazole-3-carboxylic amide derivatives were synthesized from 2- mercaptothiophene via a six-step procedure. The prepared compounds were initially evaluated for their antiprolifemtive activity using the estrogen receptors expressing MCF-7 human mammary tumor cell line in vitro. All of the prepared compounds showed moderate anti-tumor activity.
基金This work was supported by the National Natural Science Foundation of China （No.91127042, No.21103158, No.21273211, No.21473171）, the National Key Basic Research Special Foundation （No.2013CB834602 and No.2010CB923300）, the Fundamental Research Funds for the Central Universities （No.7215623603）, and the Hua-shan Mountain Scholar Program. We also thank Doctor Kang-zhen Tian and Professor Shu-ji Ye for the measurement of IR spectra of aqueous lysozyme.
文摘The amide A band of protein is sensitive to the hydrogen bands of amide groups of proteins. However, it is hard to distinguish the amide A band of aqueous protein in situ directly, since it overlaps with O-H stretching vibration of water. In this work, we presented a new analytical method of Raman ratio spectrum, which can extract the amide A band of proteins in water. To obtain the Raman ratio spectrum, the Raman spectrum of aqueous protein was divided by that of pure water. A mathematical simulation was employed to examine whether Raman ratio spectrum is effective. Two kinds of protein, lysozyme and （^-chymotrypsin were employed. The amide A bands of them in water were extracted from Raman ratio spectra. Additionally, the process of thermal denaturation of lysozyme was detected from Raman ratio spectrum. These results demonstrated the Raman ratio spectra could be employed to study the amide A modes of proteins in water.
