Radical cycloaddition reactions(RCRs) are highly effective methods for constructing complex carbo-and heterocycles,which are frequently encountered in natural products that exhibit intriguing biological properties and...Radical cycloaddition reactions(RCRs) are highly effective methods for constructing complex carbo-and heterocycles,which are frequently encountered in natural products that exhibit intriguing biological properties and hold significant potential for applications in medicinal chemistry.Radical-mediated cycloaddition strategies,which recycle radical character,are particularly appealing because they require only a catalytic amount of reagent and promise reactions with theoretically high atom economy.This review focuses on recent developments and synthetic applications in RCRs,with an emphasis on visible lightinduced radical photocycloaddition reactions(RPCRs),transition metal-catalyzed approaches,and small molecule-catalyzed methods.By highlighting some outstanding innovations and addressing current challenges,this review aims to identify potential areas for improvement.These advancements will provide more efficient pathways for the synthesis of natural product molecules and offer valuable insights for the development of new synthetic methodologies.展开更多
This study investigated the suppressive effects of Armoracia rusticana(AR)and its three main glucosinolates on both free and bound heterocyclic amines(HAs),along with their mechanisms of free radical quenching using d...This study investigated the suppressive effects of Armoracia rusticana(AR)and its three main glucosinolates on both free and bound heterocyclic amines(HAs),along with their mechanisms of free radical quenching using density functional theory.Fish patties were supplemented with varying concentrations of AR(0.5%‒1.5%)and glucosinolates(0.005%‒0.015%),showing a dose-dependent inhibition of HAs and concurrent elimination of free radicals and HAs intermediates.Glucobrassicin demonstrated the highest reactivity,which was verified by frontier orbit analysis and conceptual density functional parameters,consistent with experimental findings.Furthermore,the O-H bond connected to the sulfur atom of glucobrassicin possessed the smallest bond dissociation enthalpy(BDE)value,which indicated that this particular hydrogen atom is most susceptible to react with free radicals.Overall,AR and its glucosinolates,especially glucobrassicin,show promise as natural additives for improving food safety and quality.展开更多
Robust, ultra-flexible, and multifunctional MXene-basedelectromagnetic interference (EMI) shielding nanocomposite filmsexhibit enormous potential for applications in artificial intelligence,wireless telecommunication,...Robust, ultra-flexible, and multifunctional MXene-basedelectromagnetic interference (EMI) shielding nanocomposite filmsexhibit enormous potential for applications in artificial intelligence,wireless telecommunication, and portable/wearable electronic equipment.In this work, a nacre-inspired multifunctional heterocyclic aramid(HA)/MXene@polypyrrole (PPy) (HMP) nanocomposite paper withlarge-scale, high strength, super toughness, and excellent tolerance tocomplex conditions is fabricated through the strategy of HA/MXenehydrogel template-assisted in-situ assembly of PPy. Benefiting from the"brick-and-mortar" layered structure and the strong hydrogen-bondinginteractions among MXene, HA, and PPy, the paper exhibits remarkable mechanical performances, including high tensile strength (309.7 MPa),outstanding toughness (57.6 MJ m−3), exceptional foldability, and structural stability against ultrasonication. By using the template effect ofHA/MXene to guide the assembly of conductive polymers, the synthesized paper obtains excellent electronic conductivity. More importantly,the highly continuous conductive path enables the nanocomposite paper to achieve a splendid EMI shielding effectiveness (EMI SE) of 54.1 dBat an ultra-thin thickness (25.4 μm) and a high specific EMI SE of 17,204.7 dB cm2g−1. In addition, the papers also have excellent applicationsin electromagnetic protection, electro-/photothermal de-icing, thermal therapy, and fire safety. These findings broaden the ideas for developinghigh-performance and multifunctional MXene-based films with enormous application potential in EMI shielding and thermal management.展开更多
A strategy for the green synthesis of heterocyclicβ-ketosulfides via nucleophilic substitution ofα-halogenated ketone with het-eroaryl thiols in water media is presented.Compared with the available literature report...A strategy for the green synthesis of heterocyclicβ-ketosulfides via nucleophilic substitution ofα-halogenated ketone with het-eroaryl thiols in water media is presented.Compared with the available literature reports,this new method had the advantages of base-free,additives-free,simple operation,mild condition,greenness,high efficiency,tolerance of a broad scope of substrates.Furth-more,the reaction could easily be scaled up in gram scale and the products also could easily transformed to other useful organic compounds.Mechanism investigation indicated that the tautomerism of pyrimidine-2-thiol to pyrimidine-2(1H)-thione and the hy-drogen bonds played important roles in the reaction.展开更多
Nitrogen-containing heterocycles display a wide range of pharmacological activities attributable to their distinctive structural characteristics.They are frequently employed in the structural modification of pharmaceu...Nitrogen-containing heterocycles display a wide range of pharmacological activities attributable to their distinctive structural characteristics.They are frequently employed in the structural modification of pharmaceuticals,agrochemicals,and advanced materials.The synthesis of nitrogen-containing heterocyclic compounds represents a crucial and rapidly evolving domain within modern organic chemistry.In recent years,photocatalytic approaches have emerged as an environmentally benign and highly efficient synthetic strategy.This has provided novel pathways for constructing diverse heterocyclic architectures and has opened up new perspectives for the synthesis of drug molecules.This article reviews the efficient methods for the photocatalytic synthesis of eight different types of nitrogen-containing heterocyclic compounds in the past five years.展开更多
Gold-catalyzed amination reactions based on azides viaα-imino gold carbene intermediates have attracted extensive attention in the past decades because this methodology leads to the facile and efficient construction ...Gold-catalyzed amination reactions based on azides viaα-imino gold carbene intermediates have attracted extensive attention in the past decades because this methodology leads to the facile and efficient construction of synthetically useful N-containing molecules,especially valuable N-heterocycles.However,successful examples of intermolecular generation ofα-imino gold carbenes by using azides as amination reagents are rarely explored probably due to the weak nucleophilicity of azides.Herein,we disclose an efficient gold-catalyzed intermolecular aminative cyclopropanation of ynamides with the allyl azides,enabling flexible synthesis of a wide range of valuable 3-azabicyclo[3.1.0]hex-2-ene derivatives in good to excellent yields with excellent diastereoselectivities.Importantly,this protocol represents the first use of allyl azide as an efficient amination reagent in gold-catalyzed alkyne amination reactions.展开更多
Calcium carbide,a bulky and cheap raw chemical,is traditionally depolymerized by water to release acetylene,allowing the downstream organic transformation.In this study,hydrogen sulfide(H_(2)S),an industrial waste gas...Calcium carbide,a bulky and cheap raw chemical,is traditionally depolymerized by water to release acetylene,allowing the downstream organic transformation.In this study,hydrogen sulfide(H_(2)S),an industrial waste gas,has been exploited to depolymerize calcium carbide,which represents a strategy for the comprehensive utilization of both hydrogen sulfide and calcium carbide.As a proof of concept,a three-component condensation reaction was established to prepare thioamides directly from hydrogen sulfide and calcium carbide in high yields.Leveraging the unique properties of thioamides that possess both nucleophilic sulfur and electrophilic carbon sites,a series of novel tandem reactions were further developed to construct structurally diverse heterocyclic compounds.Our strategy not only provides a new chemical pathway for calcium carbide depolymerization,but also offers a solution for the utilization of hazardous hydrogen sulfide gas.More importantly,this approach facilitates the comprehensive and sustainable utilization of the calcium carbide resource.展开更多
A series of isomeric sandwich-type dysprosiacarboranyl complexes,including[Na(THF)_(5)][3.2'-(THF)_(2)-3.2-Dy(1,2-C_(2)B_(9)H_(11))_(x)(1'7'-C_(2)B_(9)H_(11))_(2-x))(o/m-Dy)and[Na(THF)_(5)][2.2'-(THF)_...A series of isomeric sandwich-type dysprosiacarboranyl complexes,including[Na(THF)_(5)][3.2'-(THF)_(2)-3.2-Dy(1,2-C_(2)B_(9)H_(11))_(x)(1'7'-C_(2)B_(9)H_(11))_(2-x))(o/m-Dy)and[Na(THF)_(5)][2.2'-(THF)_(2)-2.2'-Dy(1,7-C_(2)B_(9)H_(11))2](m-Dy)were synthesized by using the isomeric dicarbollide ligands,namely[nido-7,8-C2BgH_(11)]^(2-)and[nido-7,9-C_(2)B_(9)H_(11)]^(2-).The structural details of o/m-Dy and m-Dy and magnetic dynamics of m-Dy were investigated to compare with the previous study on[Na(THF)_(5)][2.2'-(THF)_(2)-2.2'-Dy(1,2-C_(2)B_(9)H_(11))_(2)]o-Dy.The bending angles of sandwiched dysprosiacarboranes are straightened so as to improve energy bar-riers(U_(eff))from 430(5)to 591(0)K.Magneto-structural correlations show that the introduction of meta-C sites within the π-electron delocalized heterocyclic ring can effectively shorten the Dy-C_(2)B_(3)centroid distance and increase the C_(2)B_(3)centroid...Dy...C_(2)B_(3)centroid bending angle which is attributed to the dif-ferences in electronegativity between C and B atoms on the ring of C_(2)B_(3)^(2-).Therefore,to further enhance the performance of single-molecule magnets(SMMs)on this basis,future endeavors should focus on diminishing the equatorial solvent molecules to make a wider C2B3...Dy...C_(2)B_(3)bending angle.展开更多
Regioselevtive functionalization of perylene diimides(PDIs)at bay area often requires multistep synthesis and strenuous recrystallization.Direct bromination of perylene diimides only afford the 1,6 and 1,7-regioisomer...Regioselevtive functionalization of perylene diimides(PDIs)at bay area often requires multistep synthesis and strenuous recrystallization.Direct bromination of perylene diimides only afford the 1,6 and 1,7-regioisomers.More importantly,the 1,6-dibromo regioisomers could only be separated by preparative HPLC.Herein,we report a promising strategy for constructing Janus backbone of BN-doped perylene diimide derivatives.This Janus-type configuration results in the unique regioselective functionalization of BN-JPDIs,which yields exclusively the 1,6-regioisomers.Further investigation shows that the Janus-type configuration leads to a net dipole moment of 1.94 D and intramolecular charge transfer,which causes substantial changes on the optoelectronic properties.Moreover,the single crystal organic field-effect transistors based on BN-JPDIs exhibit electron mobilities up to 0.57 cm^(2)V^(-1)s^(-1),showcasing their potential as versatile building block towards high-performance n-type organic semiconductors.展开更多
The demand for anisotropic aerogels with excellent comprehensive properties in cutting-edge fields such as aerospace is growing.Based on the above background,a novel heterocyclic para-aramid nanofiber/reduced graphene...The demand for anisotropic aerogels with excellent comprehensive properties in cutting-edge fields such as aerospace is growing.Based on the above background,a novel heterocyclic para-aramid nanofiber/reduced graphene oxide(HPAN/rGO)composite aerogel was prepared by combining electrospinning and unidirectional freeze-drying.The anisotropic HPAN/rGO composite aerogel exhibited a honeycomb morphology in the direction perpendicular to the growth of ice crystals,and a through-well structure of directed microchannels in the direction parallel to the temperature gradient.By varying the mass ratio of HPAN/rGO,a composite aerogel with an ultra-low density of 5.34-7.81 mg·cm^(-3) and an ultra-high porosity of 98%-99%was obtained.Benefiting from the anisotropic structure,the radial and axial thermal conductivities of HPAN/rGO-3 composite aerogel were 29.37 and 44.35 mW·m^(-1)·K^(-1),respectively.A combination of software simulation and experiments was used to analyze the effect of anisotropic structures on the thermal insulation properties of aerogels.Moreover,due to the intrinsic self-extinguishing properties of heterocyclic para-aramid and the protection of the graphene carbon layer,the composite aerogel also exhibits excellent flame retardancy properties,and its total heat release rate(THR)was only 5.8 kJ·g^(-1),which is far superior to many reported aerogels.Therefore,ultralight anisotropic HPAN/rGO composite aerogels with excellent high-temperature thermal insulation and flame retardancy properties have broad application prospects in complex environments such as aerospace.展开更多
In recent years,researchers have increasingly focused on aqueous rechargeable Zn-ion batteries(AZIBs)as a cost-effective and safe alternative to lithium-ion batteries for energy storage.Nevertheless,the limited revers...In recent years,researchers have increasingly focused on aqueous rechargeable Zn-ion batteries(AZIBs)as a cost-effective and safe alternative to lithium-ion batteries for energy storage.Nevertheless,the limited reversibility of the Zn anode and the low coulombic efficiency of the electroplating process limit the application of AZIBs.In this work,pyrrole is employed as a cost-effective electrolyte additive for stabilizing the Zn anode for the first time.By altering the coordination environment of Zn(H2O)62+,chemical and hydrogen evolution corrosion was reduced,and a molecular interface layer was in-situ constructed on the surface of the metal Zn anode,thus effectively inhibiting the corrosion of Zn anode and the growth of dendrites.In addition,the molecular interface layer based on pyrrole can effectively regulate the uniform deposition of Zn ions and limit the 2D diffusion of Zn ions.Therefore,the electrochemical performance of the metal Zn anode is greatly improved in the pyrrole-based electrolyte.At the current density of 1 mA·cm^(-2),the stable cycle can exceed 1200 h,and the average Coulomb efficiency is as high as 99%.Moreover,the full battery can have more than 400 stable cycles with a reversible capacity 247.9 mAh·g^(-1)at a current density 0.5 A·g^(-1)when assembled with V2O5 cathodes.This work provides a simple and feasible strategy for realizing the high performance of aqueous Zn-ion batteries.展开更多
Aliphatic polyesters and polycarbonates are among the promising sustainable polymers,which exhibit unique degradability and chain-chain interactions owing to their heterofunctionality.However,monocomponent aliphatic p...Aliphatic polyesters and polycarbonates are among the promising sustainable polymers,which exhibit unique degradability and chain-chain interactions owing to their heterofunctionality.However,monocomponent aliphatic polyesters and polycarbonates usually suffer from inferior properties and functionalities.By contrast,precisely modulated block copolymers composed of polyesters and polycarbonates give rise to sustainable materials with tailored performance.An efficient approach to synthesize the block copolymers is the ring-opening(co)polymerization of the heterocycle monomers.Herein,this review presents the heterocycle monomer ring-opening(co)polymerization for the formation of sequence-controlled block polyesters and polycarbonates.Available synthetic strategies,different monomers,monomer combinations and the catalyst systems for the formation of different block polyesters and polycarbonates are summarized.展开更多
Lemon oils are broadly used as flavoring agents in beverages,foods,cosmetics and pharmaceuticals,yet the adulteration of natural,particularly cold pressed lemon oils is very common in the industry due to its unmet dem...Lemon oils are broadly used as flavoring agents in beverages,foods,cosmetics and pharmaceuticals,yet the adulteration of natural,particularly cold pressed lemon oils is very common in the industry due to its unmet demand and high cost.Nowadays,most quality control(QC)analysis of lemon oils is conducted by gas chromatography(GC)analysis,which is far from a reliable method.Oxygen heterocyclic compounds(OHCs)in non-volatile fraction are gaining increasing attention in authentication process because of the nearly finger-printing profiles of OHCs in cold pressed citrus essential oils.Our goal in this study was to identify OHCs using high performance liquid chromatography(HPLC)in lemon oils,establish OHC profiles,perform stepwise logistic regression analysis(SLRA)and build effective predicting model and further determine adulterated lemon oils by referencing the OHC profiles and established models.After HPLC analyses,profiling and SLRA modeling of 154 OHCs samples of industrial lemon oils,we found that the combination of isopimpinellin and total OHC concentration are essential and robust predictors to differentiate authentic samples from adulterated lemon oils with a success rate of 98%from the 5-fold cross validation.This study provided a reliable and efficient method in determining the authenticity of lemon oils.展开更多
The design and synthesis of a novel π-conjugated fiuorescent framework by external ligand-assisted C-H olefination of heterocycles with excellent regioselectivity and broad substrate scope are reported herein.These n...The design and synthesis of a novel π-conjugated fiuorescent framework by external ligand-assisted C-H olefination of heterocycles with excellent regioselectivity and broad substrate scope are reported herein.These novel fiuorescent materials could present full-color-tunable emissions with large Stokes shifts. Furthermore, the protocol provides an opportunity to rapidly screen novel organic single-molecule whitelight materials with high fiuorescence quantum yields. The robust organic and low-cost white lightemitting diodes could rapidly be fabricated using the white-light-emitting material. Experimental data and theoretical calculations indicate that in the white-light dual emission the relatively short wavelength from high-lying singlet state emission and the relatively long wavelength from low-lying singlet state emission. The anti-Kasha dual-emission systems will provide a foundation for the development and application of organic single-molecule white light materials, effectively promoting the development and innovation of luminescent materials. In addition, this method demonstrated its potential application in the synthesis of new near-infrared(NIR) fiuorescence materials with large Stokes shifts based on the olefination of heterocycles.展开更多
A transition-metal-free strategy for the synthesis of tetrasubstituted furans is reported.Promoted by boron trifluo-ride diethyl etherate,the reaction of alkynyl sulfoxides with ynamides/ynol ethers proceeded via a ca...A transition-metal-free strategy for the synthesis of tetrasubstituted furans is reported.Promoted by boron trifluo-ride diethyl etherate,the reaction of alkynyl sulfoxides with ynamides/ynol ethers proceeded via a cascade process including cross-coupling of the two reactants,[3,3]-sulfonium rearrangement,and 5-exo-dig heterocyclization,leading to tetrasubstituted furan products.The resultant α-alkylthio groups can be used for further functionalization,such as to introduce other alkyl/aryl groups.展开更多
Ultrasonic/O3 combined process was employed to pretreat heterocyclic pesticide wastewater for increasing biodegradability and reducing biological toxicity. Influences of ultrasonic frequency, ultrasonic power, probe d...Ultrasonic/O3 combined process was employed to pretreat heterocyclic pesticide wastewater for increasing biodegradability and reducing biological toxicity. Influences of ultrasonic frequency, ultrasonic power, probe diameter, initial pH and 03 dosage on the COD removal were studied. The results showed that the ultrasonic/O3 process significantly improved the biodegradability and reduced the biological toxicity of the wastewater. The ratio of BODs/COD was increased from 0.03 to 0.55 and the EC50 increased from 11% to 52% under ultrasonic/O3 treatment. Low ultrasonic frequency brought better COD removal. Initial pH was found to have a high influence on the COD removal and alkaline conditions were more favorable. The influences of ultrasonic power and probe diameter were small. With an increase in O3 dosage, COD removal was effectively improved. The optimal operational parameters for the combined process on COD removal were ultrasonic frequency 20 kHz, initial pH 9.00, ultrasonic power 300 W and dosage of O3 454.8 mg/（L.min）, under which the efficiency of COD removal reached 67.2%.展开更多
Plasmodium falciparum(P.falciparum) is responsible for the majority of life-threatening cases of human malaria,causing 1.5-2.7 million annual deaths.The global emergence of drug-resistant malaria parasites necessitate...Plasmodium falciparum(P.falciparum) is responsible for the majority of life-threatening cases of human malaria,causing 1.5-2.7 million annual deaths.The global emergence of drug-resistant malaria parasites necessitates identification and characterisation of novel drug targets and their potential inhibitors.We identified the carbonic anhydrase(CA) genes in P.falciparum.The pfGA gene encodes an α-carbonic anhydrase,a Zn^(2+)-metalloenzme,possessing catalytic properties distinct from that of the human host CA enzyme.The amino acid sequence of the pfCA enzyme is different from the analogous protozoan and human enzymes.A library of aromatic/heterocyclic sulfonamides possessing a large diversity of scaffolds were found to be very good inhibitors for the malarial enzyme at moderate-low micromolar and submicromolar inhibitions.The structure of the groups substituting the aromatic-ureido-or aromatic-azomethine fragment of the molecule and the length of the parent sulfonamide were critical parameters for the inhibitory properties of the sulfonamides.One derivative,that is,4-(3,4-dichlorophenylureido)thioureidobcnzcnesulfonamide(compound 10) was the most effective in vitro Plasmodium falciparum CA inhibitor,and was also the most effective antimalarial compound on the in vitro P.falciparum growth inhibition.The compound 10 was also effective in vivo antimalarial agent in mice infected with Plasmodium berghei,an animal model of drug testing for human malaria infection. It is therefore concluded that the sulphonamide inhibitors targeting the parasite CA may have potential for the development of novel therapies against human malaria.展开更多
A new heterocyclic compound,named 5,5 -diisobutoxy-2,2 -bifuran(1),and four known compounds(2-5) were isolated from the roots of Cyathula officinalis Kuan.Their structures were elucidated by spectroscopic methods.Amon...A new heterocyclic compound,named 5,5 -diisobutoxy-2,2 -bifuran(1),and four known compounds(2-5) were isolated from the roots of Cyathula officinalis Kuan.Their structures were elucidated by spectroscopic methods.Among these compounds,5,5 - dibutoxy-2,2 -bifuran(2) was isolated for the first time from this plant.展开更多
Interaction between bovine serum albumin(BSA) and phosphorus heterocycles(PHs) was studied using multispectroscopic techniques. The results indicated the high binding affinity of PHs to BSA as it quenches the intrinsi...Interaction between bovine serum albumin(BSA) and phosphorus heterocycles(PHs) was studied using multispectroscopic techniques. The results indicated the high binding affinity of PHs to BSA as it quenches the intrinsic fluorescence of BSA. The experimental data suggested the fluorescence quenching mechanism between PHs and BSA as a dynamic quenching. From the UV–vis studies, the apparent association constant(K_(app)) was found to be 9.25×10~2, 1.27×10~4and 9.01×10~2L/mol for the interaction of BSA with PH-1, PH-2 and PH-3,respectively. According to the F?rster's non-radiation energy transfer(FRET) theory, the binding distances between BSA and PHs were calculated. The binding distances(r) of PH-1, PH-2 and PH-3 were found to be2.86, 3.03, and 5.12 nm, respectively, indicating energy transfer occurs between BSA and PHs. The binding constants of the PHs obtained from the fluorescence quenching data were found to be decreased with increase of temperature. The negative values of the thermodynamic parameters ΔH, ΔS and ΔG at different temperatures revealed that the binding process is spontaneous; hydrogen bonds and van der Waals interaction were the main force to stabilize the complex. The microenvironment of the protein-binding site was studied by synchronous fluorescence and circular dichroism(CD) techniques and data indicated that the conformation of BSA changed in the presence of PHs. Finally, we studied the BSA-PHs docking using Auto Dock and results suggest that PHs is located in the cleft between the domains of BSA.展开更多
基金The financial support from the National Natural Science Foundation of China (Nos.22150410339,W2432012,22301237 and 22171218)the Ministry of Science and Technology China (No.wgxz2022188) is greatly acknowledged。
文摘Radical cycloaddition reactions(RCRs) are highly effective methods for constructing complex carbo-and heterocycles,which are frequently encountered in natural products that exhibit intriguing biological properties and hold significant potential for applications in medicinal chemistry.Radical-mediated cycloaddition strategies,which recycle radical character,are particularly appealing because they require only a catalytic amount of reagent and promise reactions with theoretically high atom economy.This review focuses on recent developments and synthetic applications in RCRs,with an emphasis on visible lightinduced radical photocycloaddition reactions(RPCRs),transition metal-catalyzed approaches,and small molecule-catalyzed methods.By highlighting some outstanding innovations and addressing current challenges,this review aims to identify potential areas for improvement.These advancements will provide more efficient pathways for the synthesis of natural product molecules and offer valuable insights for the development of new synthetic methodologies.
基金supported by the National Natural Science Foundation of China(32302258,32172317)the Science and Technology Innovation Program of Hunan Province(2024RC3185)+1 种基金Hunan Provincial Natural Science Foundation of China(2023JJ40317)Changsha Municipal Natural Science Foundation(kq2202223).
文摘This study investigated the suppressive effects of Armoracia rusticana(AR)and its three main glucosinolates on both free and bound heterocyclic amines(HAs),along with their mechanisms of free radical quenching using density functional theory.Fish patties were supplemented with varying concentrations of AR(0.5%‒1.5%)and glucosinolates(0.005%‒0.015%),showing a dose-dependent inhibition of HAs and concurrent elimination of free radicals and HAs intermediates.Glucobrassicin demonstrated the highest reactivity,which was verified by frontier orbit analysis and conceptual density functional parameters,consistent with experimental findings.Furthermore,the O-H bond connected to the sulfur atom of glucobrassicin possessed the smallest bond dissociation enthalpy(BDE)value,which indicated that this particular hydrogen atom is most susceptible to react with free radicals.Overall,AR and its glucosinolates,especially glucobrassicin,show promise as natural additives for improving food safety and quality.
基金supported by the Fundamental Research Funds for the Central Universities and Heilongjiang Provincial Natural Science Foundation of China(Grant No.YQ2020E009).
文摘Robust, ultra-flexible, and multifunctional MXene-basedelectromagnetic interference (EMI) shielding nanocomposite filmsexhibit enormous potential for applications in artificial intelligence,wireless telecommunication, and portable/wearable electronic equipment.In this work, a nacre-inspired multifunctional heterocyclic aramid(HA)/MXene@polypyrrole (PPy) (HMP) nanocomposite paper withlarge-scale, high strength, super toughness, and excellent tolerance tocomplex conditions is fabricated through the strategy of HA/MXenehydrogel template-assisted in-situ assembly of PPy. Benefiting from the"brick-and-mortar" layered structure and the strong hydrogen-bondinginteractions among MXene, HA, and PPy, the paper exhibits remarkable mechanical performances, including high tensile strength (309.7 MPa),outstanding toughness (57.6 MJ m−3), exceptional foldability, and structural stability against ultrasonication. By using the template effect ofHA/MXene to guide the assembly of conductive polymers, the synthesized paper obtains excellent electronic conductivity. More importantly,the highly continuous conductive path enables the nanocomposite paper to achieve a splendid EMI shielding effectiveness (EMI SE) of 54.1 dBat an ultra-thin thickness (25.4 μm) and a high specific EMI SE of 17,204.7 dB cm2g−1. In addition, the papers also have excellent applicationsin electromagnetic protection, electro-/photothermal de-icing, thermal therapy, and fire safety. These findings broaden the ideas for developinghigh-performance and multifunctional MXene-based films with enormous application potential in EMI shielding and thermal management.
文摘A strategy for the green synthesis of heterocyclicβ-ketosulfides via nucleophilic substitution ofα-halogenated ketone with het-eroaryl thiols in water media is presented.Compared with the available literature reports,this new method had the advantages of base-free,additives-free,simple operation,mild condition,greenness,high efficiency,tolerance of a broad scope of substrates.Furth-more,the reaction could easily be scaled up in gram scale and the products also could easily transformed to other useful organic compounds.Mechanism investigation indicated that the tautomerism of pyrimidine-2-thiol to pyrimidine-2(1H)-thione and the hy-drogen bonds played important roles in the reaction.
基金Project supported by the Hunan Provincial Natural Science Foundation(No.2023JJ30525)the Hunan Provincial Department of Education Scientific Research Project(No.22A0295)+2 种基金the Hunan Province Key Laboratory for Antibody-Based Drug and Intelligent Delivery System(No.2023-KL02)the Hunan Provincial Health Commission Scientific Research Project(No.D202313057620)2024 College Student Innovation and Entrepreneurship Training Program(No.S202410555025)。
文摘Nitrogen-containing heterocycles display a wide range of pharmacological activities attributable to their distinctive structural characteristics.They are frequently employed in the structural modification of pharmaceuticals,agrochemicals,and advanced materials.The synthesis of nitrogen-containing heterocyclic compounds represents a crucial and rapidly evolving domain within modern organic chemistry.In recent years,photocatalytic approaches have emerged as an environmentally benign and highly efficient synthetic strategy.This has provided novel pathways for constructing diverse heterocyclic architectures and has opened up new perspectives for the synthesis of drug molecules.This article reviews the efficient methods for the photocatalytic synthesis of eight different types of nitrogen-containing heterocyclic compounds in the past five years.
基金financial support from the National Natural Science Foundation of China(Nos.22125108,22331004 and 22121001)Yunnan Normal University,Applied Basic Research Projects of Yunnan Province(No.202101AT070217)+1 种基金the Jiangxi Provincial Natural Science Foundation(No.20224BAB213013)the Jiangxi Provincial Department of Education in Science and Technology Program Project(No.GJJ210906)。
文摘Gold-catalyzed amination reactions based on azides viaα-imino gold carbene intermediates have attracted extensive attention in the past decades because this methodology leads to the facile and efficient construction of synthetically useful N-containing molecules,especially valuable N-heterocycles.However,successful examples of intermolecular generation ofα-imino gold carbenes by using azides as amination reagents are rarely explored probably due to the weak nucleophilicity of azides.Herein,we disclose an efficient gold-catalyzed intermolecular aminative cyclopropanation of ynamides with the allyl azides,enabling flexible synthesis of a wide range of valuable 3-azabicyclo[3.1.0]hex-2-ene derivatives in good to excellent yields with excellent diastereoselectivities.Importantly,this protocol represents the first use of allyl azide as an efficient amination reagent in gold-catalyzed alkyne amination reactions.
基金the National Natural Science Foundation of China(Nos.22379075,22471114,U23A20528)the Group Project of Developing Inner Mongolia through Talents from the Talents Work Leading Group under the CPC Inner Mongolia Autonomous Regional Committee(No.2025TEL04)+2 种基金Natural Science Foundation of Inner Mongolia Autonomous Region(No.2024LHMS02011)the Innovative Research Team in Universities of Inner Mongolia Autonomous Region(No.NMGIRT2212)Basic Scientific Research Funds of Universities directly under the Inner Mongolia Autonomous Region(Nos.ZTY2025013 and JY20240076)for financial support。
文摘Calcium carbide,a bulky and cheap raw chemical,is traditionally depolymerized by water to release acetylene,allowing the downstream organic transformation.In this study,hydrogen sulfide(H_(2)S),an industrial waste gas,has been exploited to depolymerize calcium carbide,which represents a strategy for the comprehensive utilization of both hydrogen sulfide and calcium carbide.As a proof of concept,a three-component condensation reaction was established to prepare thioamides directly from hydrogen sulfide and calcium carbide in high yields.Leveraging the unique properties of thioamides that possess both nucleophilic sulfur and electrophilic carbon sites,a series of novel tandem reactions were further developed to construct structurally diverse heterocyclic compounds.Our strategy not only provides a new chemical pathway for calcium carbide depolymerization,but also offers a solution for the utilization of hazardous hydrogen sulfide gas.More importantly,this approach facilitates the comprehensive and sustainable utilization of the calcium carbide resource.
基金the National Natural Science Foundation of China(22375157)the Programme of Introducing Talents of Discipline to Universities(B23025)+4 种基金State Key Laboratory of Electrical Insulation and Power Equipment(EIPE23402,EIPE23405)SpecialSupportPlanof ShaanxiProvincefor Young Top-notch Talent,the Fundamental Research Funds for Central Universities(xtr052023002,xzy012023024)the China Postdoctoral Science Foundation(2023M742783)Shaanxi Postdoctoral Science Foundation(2023BSHYDZZ12)the"Scientists+engineers"Team Building Project of Qin Chuang Yuan(2022KXJ-088).
文摘A series of isomeric sandwich-type dysprosiacarboranyl complexes,including[Na(THF)_(5)][3.2'-(THF)_(2)-3.2-Dy(1,2-C_(2)B_(9)H_(11))_(x)(1'7'-C_(2)B_(9)H_(11))_(2-x))(o/m-Dy)and[Na(THF)_(5)][2.2'-(THF)_(2)-2.2'-Dy(1,7-C_(2)B_(9)H_(11))2](m-Dy)were synthesized by using the isomeric dicarbollide ligands,namely[nido-7,8-C2BgH_(11)]^(2-)and[nido-7,9-C_(2)B_(9)H_(11)]^(2-).The structural details of o/m-Dy and m-Dy and magnetic dynamics of m-Dy were investigated to compare with the previous study on[Na(THF)_(5)][2.2'-(THF)_(2)-2.2'-Dy(1,2-C_(2)B_(9)H_(11))_(2)]o-Dy.The bending angles of sandwiched dysprosiacarboranes are straightened so as to improve energy bar-riers(U_(eff))from 430(5)to 591(0)K.Magneto-structural correlations show that the introduction of meta-C sites within the π-electron delocalized heterocyclic ring can effectively shorten the Dy-C_(2)B_(3)centroid distance and increase the C_(2)B_(3)centroid...Dy...C_(2)B_(3)centroid bending angle which is attributed to the dif-ferences in electronegativity between C and B atoms on the ring of C_(2)B_(3)^(2-).Therefore,to further enhance the performance of single-molecule magnets(SMMs)on this basis,future endeavors should focus on diminishing the equatorial solvent molecules to make a wider C2B3...Dy...C_(2)B_(3)bending angle.
基金support from the National Natural Science Foundation of China(Nos.22071007,22020102001,22335002)the National Key R&D Program of China(No.2022YFB3602802)+3 种基金Beijing Natural Science Foundation(No.Z220025)the National Facility for Protein Science in Shanghai,Shanghai Advanced Research Institute,CAS,for providing technical support in X-ray diffraction data collectionthe High-Performance Computing Platform of Peking University for supporting the computational workthe support of BMS Junior Fellow program。
文摘Regioselevtive functionalization of perylene diimides(PDIs)at bay area often requires multistep synthesis and strenuous recrystallization.Direct bromination of perylene diimides only afford the 1,6 and 1,7-regioisomers.More importantly,the 1,6-dibromo regioisomers could only be separated by preparative HPLC.Herein,we report a promising strategy for constructing Janus backbone of BN-doped perylene diimide derivatives.This Janus-type configuration results in the unique regioselective functionalization of BN-JPDIs,which yields exclusively the 1,6-regioisomers.Further investigation shows that the Janus-type configuration leads to a net dipole moment of 1.94 D and intramolecular charge transfer,which causes substantial changes on the optoelectronic properties.Moreover,the single crystal organic field-effect transistors based on BN-JPDIs exhibit electron mobilities up to 0.57 cm^(2)V^(-1)s^(-1),showcasing their potential as versatile building block towards high-performance n-type organic semiconductors.
基金supported by the National Key R&D Program of China(No.2021YFB3700103).
文摘The demand for anisotropic aerogels with excellent comprehensive properties in cutting-edge fields such as aerospace is growing.Based on the above background,a novel heterocyclic para-aramid nanofiber/reduced graphene oxide(HPAN/rGO)composite aerogel was prepared by combining electrospinning and unidirectional freeze-drying.The anisotropic HPAN/rGO composite aerogel exhibited a honeycomb morphology in the direction perpendicular to the growth of ice crystals,and a through-well structure of directed microchannels in the direction parallel to the temperature gradient.By varying the mass ratio of HPAN/rGO,a composite aerogel with an ultra-low density of 5.34-7.81 mg·cm^(-3) and an ultra-high porosity of 98%-99%was obtained.Benefiting from the anisotropic structure,the radial and axial thermal conductivities of HPAN/rGO-3 composite aerogel were 29.37 and 44.35 mW·m^(-1)·K^(-1),respectively.A combination of software simulation and experiments was used to analyze the effect of anisotropic structures on the thermal insulation properties of aerogels.Moreover,due to the intrinsic self-extinguishing properties of heterocyclic para-aramid and the protection of the graphene carbon layer,the composite aerogel also exhibits excellent flame retardancy properties,and its total heat release rate(THR)was only 5.8 kJ·g^(-1),which is far superior to many reported aerogels.Therefore,ultralight anisotropic HPAN/rGO composite aerogels with excellent high-temperature thermal insulation and flame retardancy properties have broad application prospects in complex environments such as aerospace.
基金supported by the National Natural Science Foundation of China(No.51902036)the Natural Science Foundation of Chongqing Science&Technology Commission(No.CSTB2022NSCQ-MSX0828)+2 种基金the Venture&Innovation Support Program for Chongqing Overseas Returnees(No.CX2021046)the Science and Technology Research Program of Chongqing Municipal Education Commission(No.KJZD-K202300802)the Research Project of Innovative Talent Training Engineering Program of Chongqing Primary and Secondary School(No.CY230801).
文摘In recent years,researchers have increasingly focused on aqueous rechargeable Zn-ion batteries(AZIBs)as a cost-effective and safe alternative to lithium-ion batteries for energy storage.Nevertheless,the limited reversibility of the Zn anode and the low coulombic efficiency of the electroplating process limit the application of AZIBs.In this work,pyrrole is employed as a cost-effective electrolyte additive for stabilizing the Zn anode for the first time.By altering the coordination environment of Zn(H2O)62+,chemical and hydrogen evolution corrosion was reduced,and a molecular interface layer was in-situ constructed on the surface of the metal Zn anode,thus effectively inhibiting the corrosion of Zn anode and the growth of dendrites.In addition,the molecular interface layer based on pyrrole can effectively regulate the uniform deposition of Zn ions and limit the 2D diffusion of Zn ions.Therefore,the electrochemical performance of the metal Zn anode is greatly improved in the pyrrole-based electrolyte.At the current density of 1 mA·cm^(-2),the stable cycle can exceed 1200 h,and the average Coulomb efficiency is as high as 99%.Moreover,the full battery can have more than 400 stable cycles with a reversible capacity 247.9 mAh·g^(-1)at a current density 0.5 A·g^(-1)when assembled with V2O5 cathodes.This work provides a simple and feasible strategy for realizing the high performance of aqueous Zn-ion batteries.
基金supported by the National Natural Science Foundation of China,Fund for Distinguished Young Scholars(No.52325301)CAS Project for Young Scientists in Basic Research(YSBR-094)the National Natural Science Foundation of China,Basic Science Center Program(No.51988102).
文摘Aliphatic polyesters and polycarbonates are among the promising sustainable polymers,which exhibit unique degradability and chain-chain interactions owing to their heterofunctionality.However,monocomponent aliphatic polyesters and polycarbonates usually suffer from inferior properties and functionalities.By contrast,precisely modulated block copolymers composed of polyesters and polycarbonates give rise to sustainable materials with tailored performance.An efficient approach to synthesize the block copolymers is the ring-opening(co)polymerization of the heterocycle monomers.Herein,this review presents the heterocycle monomer ring-opening(co)polymerization for the formation of sequence-controlled block polyesters and polycarbonates.Available synthetic strategies,different monomers,monomer combinations and the catalyst systems for the formation of different block polyesters and polycarbonates are summarized.
文摘Lemon oils are broadly used as flavoring agents in beverages,foods,cosmetics and pharmaceuticals,yet the adulteration of natural,particularly cold pressed lemon oils is very common in the industry due to its unmet demand and high cost.Nowadays,most quality control(QC)analysis of lemon oils is conducted by gas chromatography(GC)analysis,which is far from a reliable method.Oxygen heterocyclic compounds(OHCs)in non-volatile fraction are gaining increasing attention in authentication process because of the nearly finger-printing profiles of OHCs in cold pressed citrus essential oils.Our goal in this study was to identify OHCs using high performance liquid chromatography(HPLC)in lemon oils,establish OHC profiles,perform stepwise logistic regression analysis(SLRA)and build effective predicting model and further determine adulterated lemon oils by referencing the OHC profiles and established models.After HPLC analyses,profiling and SLRA modeling of 154 OHCs samples of industrial lemon oils,we found that the combination of isopimpinellin and total OHC concentration are essential and robust predictors to differentiate authentic samples from adulterated lemon oils with a success rate of 98%from the 5-fold cross validation.This study provided a reliable and efficient method in determining the authenticity of lemon oils.
基金the Fundamental Research Funds for the Central Universities (Nos. 2024CDJXY0022023CDJYGRH-YB17+4 种基金2022CDJXY-025)the Venture & Innovation Support Program for Chongqing Overseas Returnees (No. cx2022061)the Natural Science Foundation of Chongqing (No. CSTB2022NSCQ-MSX1123)the Chongqing Talents: Exceptional Young Talents Project (No. cstc2021ycjh-bgzxm0067)the Hongshen Young Scholars Program from Chongqing University (No. 0247001104426) for financial support。
文摘The design and synthesis of a novel π-conjugated fiuorescent framework by external ligand-assisted C-H olefination of heterocycles with excellent regioselectivity and broad substrate scope are reported herein.These novel fiuorescent materials could present full-color-tunable emissions with large Stokes shifts. Furthermore, the protocol provides an opportunity to rapidly screen novel organic single-molecule whitelight materials with high fiuorescence quantum yields. The robust organic and low-cost white lightemitting diodes could rapidly be fabricated using the white-light-emitting material. Experimental data and theoretical calculations indicate that in the white-light dual emission the relatively short wavelength from high-lying singlet state emission and the relatively long wavelength from low-lying singlet state emission. The anti-Kasha dual-emission systems will provide a foundation for the development and application of organic single-molecule white light materials, effectively promoting the development and innovation of luminescent materials. In addition, this method demonstrated its potential application in the synthesis of new near-infrared(NIR) fiuorescence materials with large Stokes shifts based on the olefination of heterocycles.
文摘A transition-metal-free strategy for the synthesis of tetrasubstituted furans is reported.Promoted by boron trifluo-ride diethyl etherate,the reaction of alkynyl sulfoxides with ynamides/ynol ethers proceeded via a cascade process including cross-coupling of the two reactants,[3,3]-sulfonium rearrangement,and 5-exo-dig heterocyclization,leading to tetrasubstituted furan products.The resultant α-alkylthio groups can be used for further functionalization,such as to introduce other alkyl/aryl groups.
基金supported by the National Water Pollution Control and Management Technology Major Project(No. 2008ZX07316-003)
文摘Ultrasonic/O3 combined process was employed to pretreat heterocyclic pesticide wastewater for increasing biodegradability and reducing biological toxicity. Influences of ultrasonic frequency, ultrasonic power, probe diameter, initial pH and 03 dosage on the COD removal were studied. The results showed that the ultrasonic/O3 process significantly improved the biodegradability and reduced the biological toxicity of the wastewater. The ratio of BODs/COD was increased from 0.03 to 0.55 and the EC50 increased from 11% to 52% under ultrasonic/O3 treatment. Low ultrasonic frequency brought better COD removal. Initial pH was found to have a high influence on the COD removal and alkaline conditions were more favorable. The influences of ultrasonic power and probe diameter were small. With an increase in O3 dosage, COD removal was effectively improved. The optimal operational parameters for the combined process on COD removal were ultrasonic frequency 20 kHz, initial pH 9.00, ultrasonic power 300 W and dosage of O3 454.8 mg/（L.min）, under which the efficiency of COD removal reached 67.2%.
基金Supported by a grant from UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases(No.900142,930143,960103,970074,990490)the National Science and Technology Development Agency of Thailand(Career Development Award ID no.01-38-007)the Thailand Research Fund(BasicResearch Grants ID No.BRG/13/2543.BRG4580020.BRG 4880006)
文摘Plasmodium falciparum(P.falciparum) is responsible for the majority of life-threatening cases of human malaria,causing 1.5-2.7 million annual deaths.The global emergence of drug-resistant malaria parasites necessitates identification and characterisation of novel drug targets and their potential inhibitors.We identified the carbonic anhydrase(CA) genes in P.falciparum.The pfGA gene encodes an α-carbonic anhydrase,a Zn^(2+)-metalloenzme,possessing catalytic properties distinct from that of the human host CA enzyme.The amino acid sequence of the pfCA enzyme is different from the analogous protozoan and human enzymes.A library of aromatic/heterocyclic sulfonamides possessing a large diversity of scaffolds were found to be very good inhibitors for the malarial enzyme at moderate-low micromolar and submicromolar inhibitions.The structure of the groups substituting the aromatic-ureido-or aromatic-azomethine fragment of the molecule and the length of the parent sulfonamide were critical parameters for the inhibitory properties of the sulfonamides.One derivative,that is,4-(3,4-dichlorophenylureido)thioureidobcnzcnesulfonamide(compound 10) was the most effective in vitro Plasmodium falciparum CA inhibitor,and was also the most effective antimalarial compound on the in vitro P.falciparum growth inhibition.The compound 10 was also effective in vivo antimalarial agent in mice infected with Plasmodium berghei,an animal model of drug testing for human malaria infection. It is therefore concluded that the sulphonamide inhibitors targeting the parasite CA may have potential for the development of novel therapies against human malaria.
基金the Natural Science Foundation of Tianjin(No.06YFJMJC15800) for the financial support.
文摘A new heterocyclic compound,named 5,5 -diisobutoxy-2,2 -bifuran(1),and four known compounds(2-5) were isolated from the roots of Cyathula officinalis Kuan.Their structures were elucidated by spectroscopic methods.Among these compounds,5,5 - dibutoxy-2,2 -bifuran(2) was isolated for the first time from this plant.
文摘Interaction between bovine serum albumin(BSA) and phosphorus heterocycles(PHs) was studied using multispectroscopic techniques. The results indicated the high binding affinity of PHs to BSA as it quenches the intrinsic fluorescence of BSA. The experimental data suggested the fluorescence quenching mechanism between PHs and BSA as a dynamic quenching. From the UV–vis studies, the apparent association constant(K_(app)) was found to be 9.25×10~2, 1.27×10~4and 9.01×10~2L/mol for the interaction of BSA with PH-1, PH-2 and PH-3,respectively. According to the F?rster's non-radiation energy transfer(FRET) theory, the binding distances between BSA and PHs were calculated. The binding distances(r) of PH-1, PH-2 and PH-3 were found to be2.86, 3.03, and 5.12 nm, respectively, indicating energy transfer occurs between BSA and PHs. The binding constants of the PHs obtained from the fluorescence quenching data were found to be decreased with increase of temperature. The negative values of the thermodynamic parameters ΔH, ΔS and ΔG at different temperatures revealed that the binding process is spontaneous; hydrogen bonds and van der Waals interaction were the main force to stabilize the complex. The microenvironment of the protein-binding site was studied by synchronous fluorescence and circular dichroism(CD) techniques and data indicated that the conformation of BSA changed in the presence of PHs. Finally, we studied the BSA-PHs docking using Auto Dock and results suggest that PHs is located in the cleft between the domains of BSA.
