Machine learning(ML)has demon-strated significant potential in en-hancing the predictive capabilities of density functional theory methods.In this study,we develop an ML model for correcting B3LYP-D,a density function...Machine learning(ML)has demon-strated significant potential in en-hancing the predictive capabilities of density functional theory methods.In this study,we develop an ML model for correcting B3LYP-D,a density functional approximation that incorporates dispersion correc-tions for non-covalent interactions.This model utilizes semilocal elec-tron density descriptors,and is trained with accurate reference data for both relative and ab-solute energies.Extensive benchmark tests reveal that the ML correction substantially en-hances the generalization ability of the B3LYP-D functional,improving the predictions of at-omization and dissociation energies for complex molecular systems.It retains the accuracy of B3LYP-D in predicting reaction barrier heights and non-covalent interactions while enabling efficient,fully self-consistent field calculations.This work signifies a promising advancement in the development of ML-corrected functionals that surpass the performance of traditional B3LYP-D.展开更多
The reduced graphene oxide(RGO)/bisphenol A(BPA)composites were prepared by an adsorption-reduction method.The composites are characterized by X-ray diffraction(XRD),UV-vis,thermogravimetric(TG)analysis,field emission...The reduced graphene oxide(RGO)/bisphenol A(BPA)composites were prepared by an adsorption-reduction method.The composites are characterized by X-ray diffraction(XRD),UV-vis,thermogravimetric(TG)analysis,field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM).The results confirm that BPA is adsorbed on the basal plane of RGO byπ-πstacking interaction.Furthermore,the electrochemical behaviors were evaluated by cyclic voltammetry,galvanostatic charge/discharge techniques and electrochemical impedance spectroscopy(EIS).The results show that the RGO/BPA nanocomposites exhibit ultrahigh specific capacitance of 466 F•g^(−1) at a current density of 1 A•g^(−1),excellent rate capability(more than 81%retention at 10 A•g^(−1) relative to 1 A•g^(−1))and superior cycling stability(90%capacitance decay after 4000 cycles).Consequently,the RGO/BPA nanocomposites can be regarded as promising electrode materials for supercapacitor applications.展开更多
2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) is a stoichiometric oxidant that is frequently used in traditional organic synthesis. Recently, the rapid development of organic electrochemistry has led to new advancem...2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) is a stoichiometric oxidant that is frequently used in traditional organic synthesis. Recently, the rapid development of organic electrochemistry has led to new advancements in DDQ-catalyzed C—H bonds functionalization. Moreover, the challenging C—H functionalization of electron-deficient arenes has been achieved through the merger of electrochemical DDQ catalysis and photoirradiation. In addition, the synthetic utility of electrophotochemical DDQ catalysis was further demonstrated by the nucleophilic aromatic substitution (SNAr) reaction of unactivated aryl fluorides. The recent developments in electro- and electrophotochemical DDQ-catalyzed C—H/C—F func- tionalizations with attention to their strategies and mechanistic insights are summarized. It is hoped that this not only deepens the understanding of this field, but also helps relevant researchers expand the application scope of DDQ catalysis.展开更多
Difunctionalization of unsaturated hydrocarbons is a pivotal synthetic strategy enabling the conversion of alkenes and alkynes into high value-added compounds.It allows for the introduction of two functional groups in...Difunctionalization of unsaturated hydrocarbons is a pivotal synthetic strategy enabling the conversion of alkenes and alkynes into high value-added compounds.It allows for the introduction of two functional groups into the unsaturated bond in a single step,facilitating the efficient construction of complex molecular architectures,which has been widely utilized in material chemistry,pharmaceutical and fine chemical synthesis.Recently,significant progress has been made via free radical-mediated difunctionalization due to the extensive application of photocatalysis.However,highly selective difunc-tionalization reactions still remain challenging.The research progress of selective difunctionalization of unsaturated hydro-carbons using a free radical addition/functional group migration strategy over the past decade is summarized,and synthetic strategies and key reaction steps are systematically elaborated.展开更多
This study reviews light-responsive polymers in various applications,including drug delivery,information storage,sensor,self-healing material,antibacterial or anti-fouling,and environmental applications.Light-responsi...This study reviews light-responsive polymers in various applications,including drug delivery,information storage,sensor,self-healing material,antibacterial or anti-fouling,and environmental applications.Light-responsive polymers are a new material type being developed for various medical,electronics,engineering,and environmental applications.The working principle of light-responsive materials is based on metalligand interactions or non-covalent interactions between polymer functional groups,metal ions,and other filler functional groups.Light irradiation causes physical and mechanical changes in drug delivery and antibacterial systems,which results in the materials releasing more drugs or antibacterial substances.When materials in information storage devices and sensors are exposed to light,they can change color or glow.This has been applied for data storage to reveal QR codes under UV light.Additionally,this review discusses the thermodynamic aspects and computer modeling of light-responsive materials to emphasize the importance and development of these materials.Finally,light-responsive polymer development for various applications is presented.展开更多
Visible-light-mediated O-H functionalization reactions of alcohols with diazo compounds have been fully developed in recent years.However,alkenyl and acetylenic alcohols were rarely examined in these reactions due to ...Visible-light-mediated O-H functionalization reactions of alcohols with diazo compounds have been fully developed in recent years.However,alkenyl and acetylenic alcohols were rarely examined in these reactions due to the inevitable side reactions involving cycloaddition.Herein,the visible-light-mediated O-H functionalization reactions of alkenyl alcohols with diazo compounds were developed.This process competed favorably with the cycloaddition reaction.A series of multifunctional ethers were provided in low to high yields with aryldiazoacetates or 3-diazooxindoles.Biologically relevant spirooxindole-fused oxacycle could be easily accessed from the O-H functionalization product of alkenyl alcohol and 3-diazooxindole.展开更多
Asymmetric allylic C—H functionalization is a valuable and challenging research area. Different from the conventional direct allylic C—H cleavage strategy, transition metal-catalyzed migratory allylic substitution o...Asymmetric allylic C—H functionalization is a valuable and challenging research area. Different from the conventional direct allylic C—H cleavage strategy, transition metal-catalyzed migratory allylic substitution of remote dienes has emerged as a new route to achieve allylic C—H functionalization enantioselectively. This review provides a detailed summary of the development and advance of this strategy, introduces the related mechanistic processes, and discusses the area based on the types of catalysts and products.展开更多
Chemical recycling/upcycling of plastics has emerged as one of the most promising strategies for the plastic circular economy,enabling the depolymerization and functionalization of plastics into valuable monomers and ...Chemical recycling/upcycling of plastics has emerged as one of the most promising strategies for the plastic circular economy,enabling the depolymerization and functionalization of plastics into valuable monomers and chemicals.However,studies on the depolymerization and functionalization of challenging super engineering plastics have remained in early stage and underexplored.In this review,we would like to discuss the representative accomplishments and mechanism insights on chemical protocols achieved in depolymerization of super engineering plastics,especially for poly(phenylene sulfide)(PPS),poly(aryl ether)s including poly(ether ether ketone)(PEEK),polysulfone(PSU),polyphenylsulfone(PPSU)and polyethersulfone(PES).We anticipate that this review will provide an overall perspective on the current status and future trends of this emerging field.展开更多
The transition metal-catalyzed C–H activation have been considered as increasingly useful approach for installing new functional groups onto organic small molecules due to their high step-and atom-economy,the abundan...The transition metal-catalyzed C–H activation have been considered as increasingly useful approach for installing new functional groups onto organic small molecules due to their high step-and atom-economy,the abundance of hydrocarbon compounds,and the potential for late-stage functionalization of complex organic molecules.The ortho-and meta-C-H activation and functionalization of aromatic compounds have been widely explored in recent years,however the distal para-C-H activation and functionalization has remained a significant challenge because of the difficulty in forming energetically favorable metallacyclic transition states.The utilization of appropriate directing groups or templates as well as the meticulous design of catalysts and ligands has proven to be effective in transition-metal-catalyzed remote para-C-H bonds activation and functionalization of aromatic compounds.This review aims to summarize the strategies for controlling para-selective C–H functionalization using the directing group,template engineering,and catalyst/ligand design under transition metals catalysis in recent years.展开更多
Cp_(2)TiCl_(2) as a Lewis acid precursor and nicotinic acid as a ligand have been used synergistically for the one-pot synthesis of 2-(N-substituted amino)-1,4-naphthoquinones.This method establishes a general strateg...Cp_(2)TiCl_(2) as a Lewis acid precursor and nicotinic acid as a ligand have been used synergistically for the one-pot synthesis of 2-(N-substituted amino)-1,4-naphthoquinones.This method establishes a general strategy for the functionalization and conversion of C-H bonds of 1,4-naphthoquinones into C-N bonds,providing an effective route to synthesize 2-(N-substituted amino)-1,4-naphthoquinone with high yield under mild conditions.Additionally,the synergistic catalytic mechanism was investigated by 1H NMR titration experiments and LC-MS analysis,with experimental results sufficiently and consistently supporting the proposed mechanism of the catalytic cycle.展开更多
In contrast to the predominant mono or difunctionalization of alkenes,the multi-site functionalization of alkenes involving the synergistic formation of more than two new C–C or C–X bonds is much challenging,especia...In contrast to the predominant mono or difunctionalization of alkenes,the multi-site functionalization of alkenes involving the synergistic formation of more than two new C–C or C–X bonds is much challenging,especially for developing new reaction pathway to afford the functional heterocycle compounds with aggregation-induced emission(AIE)property has been rarely reported.In present work,the multi-site functionalization of in situ generated alkenes with indoles has been developed for the synthesis of diversely functionalized carbazoles through the synergistic construction of multiple C–C bonds and C=O bond.A proposed reaction sequence involving C–H alkenylation/radical oxygen atom transfer/Diels-Alder cycloaddition/dehydrogenative aromatization was supported by experiments and density functional theory calculations.Further derivative carbazole-linked-quinoxaline skeletons represent a class of AIEgens with acceptor-donor-acceptor configuration,which generated the desired twisted intramolecular charge transfer(TICT)AIE properties and could be used as fluorescent probes for detecting the micrometer-sized phase separation of polymer blends.The protocol provides a concise route for the synthesis and application of carbazole-based AIE luminogens.展开更多
UiO-66-H MOFs can effectively catalyze the direct selective oxidation of methane(DSOM)to high value-added oxygenates under mild conditions.However,UiO-66-NH_(2)with benzene-1,4-dicarboxylate(NH_(2)-BDC)ligand modifyin...UiO-66-H MOFs can effectively catalyze the direct selective oxidation of methane(DSOM)to high value-added oxygenates under mild conditions.However,UiO-66-NH_(2)with benzene-1,4-dicarboxylate(NH_(2)-BDC)ligand modifying the Zr-oxo nodes exhibits relatively inferior catalytic performance for DSOM.Here,a combination of density functional theory(DFT)calculations and experiments was employed to explore the underlying reasons for the limited catalytic activity of UiO-66-NH_(2).The results indicate that the methane hydroxylation performance of UiO-66-NH_(2)is almost unaffected by the increase of·OH concentration.This is attributed to the formation of substantial non-covalent hydrogen bonds between the oxygen atoms of oxygenic species on the Zr-oxo nodes and the hydrogen atoms of-NH_(2)groups,which diminishes the spin density distribution on the active sites of(·OH)m/UiO-66-NH_(2),leading to minimal change of the adsorption energy of CH_(4).Additionally,the calculated adsorption energies(Eads)of CH_(4)exhibit a linear relationship with the catalytic activity of UiO-66-NH_(2)for DSOM reaction.展开更多
Chemical functionalization of graphene is a topic of paramount importance to broaden its applications in chemistry,physics,and biological science but remains a great challenge due to its low chemical activity and poor...Chemical functionalization of graphene is a topic of paramount importance to broaden its applications in chemistry,physics,and biological science but remains a great challenge due to its low chemical activity and poor dispersion.Here,we report a strategy for the photosynergetic electrochemical functionalization of graphene(EFG).By using chloride ion(Cl^(-))as the intercalation anions and co-reactants,the electrogenerated radicals confined in the expanded graphite layers enable efficient radical addition reaction,thus grasping crystallineperfect EFG.We found that the ultraviolet irradiation and applied voltage have increased the surface/interface concentration of Cl,thus boosting the functionalization of graphene.Theoretical calculation and experimental results verified the oxygen evolution reaction(OER)on EFG has been improved by regulating the doping of chlorine atoms.In addition,the reduced interlayer distance and enhanced electrostatic repulsion near the basal plane endow the fabricated EFG-based membrane with high salt retention.This work highlights a method for the in situ functionalization of graphene and the subsequent applications in OER and water desalination.展开更多
Organofluorines play a crucial role in medicine,agrochemicals,and materials science.Adding fluorine to molecules creates structures with specific beneficial properties or tunes properties through interactions with the...Organofluorines play a crucial role in medicine,agrochemicals,and materials science.Adding fluorine to molecules creates structures with specific beneficial properties or tunes properties through interactions with their environment.Many popular pharmaceuticals and agrochemicals contain fluorine because it enhances hydrogen bonding at protein’s active sites.展开更多
Amino acids are the building blocks of proteins and play vital roles in both biological systems and drug development.In recent years,increasing attention has been given to the functionalization of amino acid derivativ...Amino acids are the building blocks of proteins and play vital roles in both biological systems and drug development.In recent years,increasing attention has been given to the functionalization of amino acid derivatives.Since the introduction of therapeutic insulin in the early 20th century,the conjugation of drug molecules with amino acids and peptides has been pivotal in driving advancements in drug discovery and become an integral part of modern medical practice.Currently,over a hundred peptide-drug conjugates have received global approval and are widely used to treat diseases such as diabetes,cancer,chronic pain,and multiple sclerosis.Key technologies for conjugating peptides with bioactive molecules include antibody-drug conjugates(ADCs),peptide-drug conjugates(PDCs),and proteolysis targeting chimeras(PROTACs).Significant efforts have been dedicated to developing strategies for the modification of amino acids and peptides,with particular focus on site-selective C-H alkylation/arylation reactions.These reactions are crucial for synthesizing bioactive molecules,as they enable the precise introduction of functional groups at specific positions,thereby improving the pharmacological properties of the resulting compounds.展开更多
The synergistic effect of conventional flame-retardant elements and graphene has received extensive attention in the development of a new class of flame retardants. Compared to covalent modification, the noncovalent s...The synergistic effect of conventional flame-retardant elements and graphene has received extensive attention in the development of a new class of flame retardants. Compared to covalent modification, the noncovalent strategy is simpler and expeditious and entirely preserves the original quality of graphene. Thus, non-covalently functionalized graphene oxide(FGO) with a phosphorus–nitrogen compound was successfully prepared via a one-pot process in this study. Polyethyleneimine and FGO were alternatively deposited on the surface of a poly(vinyl alcohol)(PVA) film via layer-by-layer assembly driven by electrostatic interaction, imparting excellent flame retardancy to the coated PVA film. The multilayer FGO-based coating formed a protective shield encapsulating the PVA matrix, effectively blocking the transfer of heat and mass during combustion. The coated PVA has a higher initial decomposition temperature of about 260 °C and a nearly 60% reduction in total heat release than neat PVA does. Our results may have a promising prospect for flame-retardant polymers.展开更多
In this study,precise control over the thickness and termination of Ti3C2TX MXene flakes is achieved to enhance their electrical properties,environmental stability,and gas-sensing performance.Utilizing a hybrid method...In this study,precise control over the thickness and termination of Ti3C2TX MXene flakes is achieved to enhance their electrical properties,environmental stability,and gas-sensing performance.Utilizing a hybrid method involving high-pressure processing,stirring,and immiscible solutions,sub-100 nm MXene flake thickness is achieved within the MXene film on the Si-wafer.Functionalization control is achieved by defunctionalizing MXene at 650℃ under vacuum and H2 gas in a CVD furnace,followed by refunctionalization with iodine and bromine vaporization from a bubbler attached to the CVD.Notably,the introduction of iodine,which has a larger atomic size,lower electronegativity,reduce shielding effect,and lower hydrophilicity(contact angle:99°),profoundly affecting MXene.It improves the surface area(36.2 cm^(2) g^(-1)),oxidation stability in aqueous/ambient environments(21 days/80 days),and film conductivity(749 S m^(-1)).Additionally,it significantly enhances the gas-sensing performance,including the sensitivity(0.1119Ωppm^(-1)),response(0.2% and 23%to 50 ppb and 200 ppm NO_(2)),and response/recovery times(90/100 s).The reduced shielding effect of the–I-terminals and the metallic characteristics of MXene enhance the selectivity of I-MXene toward NO2.This approach paves the way for the development of stable and high-performance gas-sensing two-dimensional materials with promising prospects for future studies.展开更多
Mercury ion(Hg^(2+)),as one of the most toxic heavy metal ions,accumulates easily in the environment,which can generate potential hazards to the ecosystem and human health.To effectively detect and remove Hg^(2+),we f...Mercury ion(Hg^(2+)),as one of the most toxic heavy metal ions,accumulates easily in the environment,which can generate potential hazards to the ecosystem and human health.To effectively detect and remove Hg^(2+),we fabricated four types of carbon dots(CDs)using carboxymethyl nanocellulose as a carbon source doped with different elements using a hydrothermal method.All the CDs exhibited a strong fluorescence emission,excitation-dependent emission and possessed good water dispersibility.Moreover,the four fluorescent CDs were used for Hg^(2+)recognition in aqueous solution,where the CDs-N exhibited better sensitivity and selectivity for Hg^(2+)detection,with a low limit of detection of 8.29×10^(-6)mol/L.It was determined that the fluorescence quenching could be ascribed to a photoinduced charge-transfer processes between Hg^(2+)and the CDs.In addition,the CDs-N were used as a smart invisible ink for anticounterfeiting,information encryption and decryption.Furthermore,the CDs-N were immersed into a cellulose(CMC)-based hydrogel network to prepare fluorescent hydrogels capable of simultaneously detecting and adsorbing Hg^(2+).We anticipate that this research will open possibilities for a green method to synthesize fluorescent CDs for metal ion detection and fluorescent ink production.展开更多
Schwann cell transplantation is considered one of the most promising cell-based therapy to repair injured spinal cord due to its unique growth-promoting and myelin-forming properties.A the Food and Drug Administration...Schwann cell transplantation is considered one of the most promising cell-based therapy to repair injured spinal cord due to its unique growth-promoting and myelin-forming properties.A the Food and Drug Administration-approved Phase I clinical trial has been conducted to evaluate the safety of transplanted human autologous Schwann cells to treat patients with spinal cord injury.A major challenge for Schwann cell transplantation is that grafted Schwann cells are confined within the lesion cavity,and they do not migrate into the host environment due to the inhibitory barrier formed by injury-induced glial scar,thus limiting axonal reentry into the host spinal cord.Here we introduce a combinatorial strategy by suppressing the inhibitory extracellular environment with injection of lentivirus-mediated transfection of chondroitinase ABC gene at the rostral and caudal borders of the lesion site and simultaneously leveraging the repair capacity of transplanted Schwann cells in adult rats following a mid-thoracic contusive spinal cord injury.We report that when the glial scar was degraded by chondroitinase ABC at the rostral and caudal lesion borders,Schwann cells migrated for considerable distances in both rostral and caudal directions.Such Schwann cell migration led to enhanced axonal regrowth,including the serotonergic and dopaminergic axons originating from supraspinal regions,and promoted recovery of locomotor and urinary bladder functions.Importantly,the Schwann cell survival and axonal regrowth persisted up to 6 months after the injury,even when treatment was delayed for 3 months to mimic chronic spinal cord injury.These findings collectively show promising evidence for a combinatorial strategy with chondroitinase ABC and Schwann cells in promoting remodeling and recovery of function following spinal cord injury.展开更多
Traumatic brain injury involves complex pathophysiological mechanisms,among which oxidative stress significantly contributes to the occurrence of secondary injury.In this study,we evaluated hypidone hydrochloride(YL-0...Traumatic brain injury involves complex pathophysiological mechanisms,among which oxidative stress significantly contributes to the occurrence of secondary injury.In this study,we evaluated hypidone hydrochloride(YL-0919),a self-developed antidepressant with selective sigma-1 receptor agonist properties,and its associated mechanisms and targets in traumatic brain injury.Behavioral experiments to assess functional deficits were followed by assessment of neuronal damage through histological analyses and examination of blood-brain barrier permeability and brain edema.Next,we investigated the antioxidative effects of YL-0919 by assessing the levels of traditional markers of oxidative stress in vivo in mice and in vitro in HT22 cells.Finally,the targeted action of YL-0919 was verified by employing a sigma-1 receptor antagonist(BD-1047).Our findings demonstrated that YL-0919 markedly improved deficits in motor function and spatial cognition on day 3 post traumatic brain injury,while also decreasing neuronal mortality and reversing blood-brain barrier disruption and brain edema.Furthermore,YL-0919 effectively combated oxidative stress both in vivo and in vitro.The protective effects of YL-0919 were partially inhibited by BD-1047.These results indicated that YL-0919 relieved impairments in motor and spatial cognition by restraining oxidative stress,a neuroprotective effect that was partially reversed by the sigma-1 receptor antagonist BD-1047.YL-0919 may have potential as a new treatment for traumatic brain injury.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22393912,22425301,22373091,22173088)the AI for Science Foundation of Fudan University(No.Fudan X24AI023)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0450101).
文摘Machine learning(ML)has demon-strated significant potential in en-hancing the predictive capabilities of density functional theory methods.In this study,we develop an ML model for correcting B3LYP-D,a density functional approximation that incorporates dispersion correc-tions for non-covalent interactions.This model utilizes semilocal elec-tron density descriptors,and is trained with accurate reference data for both relative and ab-solute energies.Extensive benchmark tests reveal that the ML correction substantially en-hances the generalization ability of the B3LYP-D functional,improving the predictions of at-omization and dissociation energies for complex molecular systems.It retains the accuracy of B3LYP-D in predicting reaction barrier heights and non-covalent interactions while enabling efficient,fully self-consistent field calculations.This work signifies a promising advancement in the development of ML-corrected functionals that surpass the performance of traditional B3LYP-D.
基金support offered by the National Natural Science Foundation of China(Nos.20963009 and 21163017)Specialized Research Fund for the Doctoral Program of Higher Education,China(No.20126203110001).
文摘The reduced graphene oxide(RGO)/bisphenol A(BPA)composites were prepared by an adsorption-reduction method.The composites are characterized by X-ray diffraction(XRD),UV-vis,thermogravimetric(TG)analysis,field emission scanning electron microscopy(FESEM),transmission electron microscopy(TEM).The results confirm that BPA is adsorbed on the basal plane of RGO byπ-πstacking interaction.Furthermore,the electrochemical behaviors were evaluated by cyclic voltammetry,galvanostatic charge/discharge techniques and electrochemical impedance spectroscopy(EIS).The results show that the RGO/BPA nanocomposites exhibit ultrahigh specific capacitance of 466 F•g^(−1) at a current density of 1 A•g^(−1),excellent rate capability(more than 81%retention at 10 A•g^(−1) relative to 1 A•g^(−1))and superior cycling stability(90%capacitance decay after 4000 cycles).Consequently,the RGO/BPA nanocomposites can be regarded as promising electrode materials for supercapacitor applications.
文摘2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) is a stoichiometric oxidant that is frequently used in traditional organic synthesis. Recently, the rapid development of organic electrochemistry has led to new advancements in DDQ-catalyzed C—H bonds functionalization. Moreover, the challenging C—H functionalization of electron-deficient arenes has been achieved through the merger of electrochemical DDQ catalysis and photoirradiation. In addition, the synthetic utility of electrophotochemical DDQ catalysis was further demonstrated by the nucleophilic aromatic substitution (SNAr) reaction of unactivated aryl fluorides. The recent developments in electro- and electrophotochemical DDQ-catalyzed C—H/C—F func- tionalizations with attention to their strategies and mechanistic insights are summarized. It is hoped that this not only deepens the understanding of this field, but also helps relevant researchers expand the application scope of DDQ catalysis.
文摘Difunctionalization of unsaturated hydrocarbons is a pivotal synthetic strategy enabling the conversion of alkenes and alkynes into high value-added compounds.It allows for the introduction of two functional groups into the unsaturated bond in a single step,facilitating the efficient construction of complex molecular architectures,which has been widely utilized in material chemistry,pharmaceutical and fine chemical synthesis.Recently,significant progress has been made via free radical-mediated difunctionalization due to the extensive application of photocatalysis.However,highly selective difunc-tionalization reactions still remain challenging.The research progress of selective difunctionalization of unsaturated hydro-carbons using a free radical addition/functional group migration strategy over the past decade is summarized,and synthetic strategies and key reaction steps are systematically elaborated.
基金the Franco-Thai Cooperation Programme in Higher Education and Research(Franco-Thai Mobility Programme/PHC SIAM)Year 2024-2025。
文摘This study reviews light-responsive polymers in various applications,including drug delivery,information storage,sensor,self-healing material,antibacterial or anti-fouling,and environmental applications.Light-responsive polymers are a new material type being developed for various medical,electronics,engineering,and environmental applications.The working principle of light-responsive materials is based on metalligand interactions or non-covalent interactions between polymer functional groups,metal ions,and other filler functional groups.Light irradiation causes physical and mechanical changes in drug delivery and antibacterial systems,which results in the materials releasing more drugs or antibacterial substances.When materials in information storage devices and sensors are exposed to light,they can change color or glow.This has been applied for data storage to reveal QR codes under UV light.Additionally,this review discusses the thermodynamic aspects and computer modeling of light-responsive materials to emphasize the importance and development of these materials.Finally,light-responsive polymer development for various applications is presented.
文摘Visible-light-mediated O-H functionalization reactions of alcohols with diazo compounds have been fully developed in recent years.However,alkenyl and acetylenic alcohols were rarely examined in these reactions due to the inevitable side reactions involving cycloaddition.Herein,the visible-light-mediated O-H functionalization reactions of alkenyl alcohols with diazo compounds were developed.This process competed favorably with the cycloaddition reaction.A series of multifunctional ethers were provided in low to high yields with aryldiazoacetates or 3-diazooxindoles.Biologically relevant spirooxindole-fused oxacycle could be easily accessed from the O-H functionalization product of alkenyl alcohol and 3-diazooxindole.
文摘Asymmetric allylic C—H functionalization is a valuable and challenging research area. Different from the conventional direct allylic C—H cleavage strategy, transition metal-catalyzed migratory allylic substitution of remote dienes has emerged as a new route to achieve allylic C—H functionalization enantioselectively. This review provides a detailed summary of the development and advance of this strategy, introduces the related mechanistic processes, and discusses the area based on the types of catalysts and products.
基金supported by the National Natural Science Foundation of China(Nos.22125103 and 22301077)STCSM(22JC140100)Shanghai Pujiang Program(No.22PJ1403200)。
文摘Chemical recycling/upcycling of plastics has emerged as one of the most promising strategies for the plastic circular economy,enabling the depolymerization and functionalization of plastics into valuable monomers and chemicals.However,studies on the depolymerization and functionalization of challenging super engineering plastics have remained in early stage and underexplored.In this review,we would like to discuss the representative accomplishments and mechanism insights on chemical protocols achieved in depolymerization of super engineering plastics,especially for poly(phenylene sulfide)(PPS),poly(aryl ether)s including poly(ether ether ketone)(PEEK),polysulfone(PSU),polyphenylsulfone(PPSU)and polyethersulfone(PES).We anticipate that this review will provide an overall perspective on the current status and future trends of this emerging field.
基金support from the National Natural Science Foundation of China(No.21901206)Postdoctoral Science Foundation of China(No.2022M712589)+2 种基金General Key R&D Projects in Shaanxi Province(No.2023-YBGY-321)Natural Science Foundation of Chongqing(No.CSTB2022NSCQ-MSX0826)National&Local Joint Engineering Research Center for mineral Salt Deep Utilization,Huaiyin Institute of Technology(No.SF202407)for financial support。
文摘The transition metal-catalyzed C–H activation have been considered as increasingly useful approach for installing new functional groups onto organic small molecules due to their high step-and atom-economy,the abundance of hydrocarbon compounds,and the potential for late-stage functionalization of complex organic molecules.The ortho-and meta-C-H activation and functionalization of aromatic compounds have been widely explored in recent years,however the distal para-C-H activation and functionalization has remained a significant challenge because of the difficulty in forming energetically favorable metallacyclic transition states.The utilization of appropriate directing groups or templates as well as the meticulous design of catalysts and ligands has proven to be effective in transition-metal-catalyzed remote para-C-H bonds activation and functionalization of aromatic compounds.This review aims to summarize the strategies for controlling para-selective C–H functionalization using the directing group,template engineering,and catalyst/ligand design under transition metals catalysis in recent years.
基金2024 Special Talent Introduction Projects of Key R&D Program of Ningxia Hui Autonomous Region(2024BEH04049)the 2024 Guyuan City Innovation-Driven Achievement Transformation Project(2024BGTYF01-47)2025 Ningxia Natural Science Foundation Program(2025AAC030624).
文摘Cp_(2)TiCl_(2) as a Lewis acid precursor and nicotinic acid as a ligand have been used synergistically for the one-pot synthesis of 2-(N-substituted amino)-1,4-naphthoquinones.This method establishes a general strategy for the functionalization and conversion of C-H bonds of 1,4-naphthoquinones into C-N bonds,providing an effective route to synthesize 2-(N-substituted amino)-1,4-naphthoquinone with high yield under mild conditions.Additionally,the synergistic catalytic mechanism was investigated by 1H NMR titration experiments and LC-MS analysis,with experimental results sufficiently and consistently supporting the proposed mechanism of the catalytic cycle.
文摘In contrast to the predominant mono or difunctionalization of alkenes,the multi-site functionalization of alkenes involving the synergistic formation of more than two new C–C or C–X bonds is much challenging,especially for developing new reaction pathway to afford the functional heterocycle compounds with aggregation-induced emission(AIE)property has been rarely reported.In present work,the multi-site functionalization of in situ generated alkenes with indoles has been developed for the synthesis of diversely functionalized carbazoles through the synergistic construction of multiple C–C bonds and C=O bond.A proposed reaction sequence involving C–H alkenylation/radical oxygen atom transfer/Diels-Alder cycloaddition/dehydrogenative aromatization was supported by experiments and density functional theory calculations.Further derivative carbazole-linked-quinoxaline skeletons represent a class of AIEgens with acceptor-donor-acceptor configuration,which generated the desired twisted intramolecular charge transfer(TICT)AIE properties and could be used as fluorescent probes for detecting the micrometer-sized phase separation of polymer blends.The protocol provides a concise route for the synthesis and application of carbazole-based AIE luminogens.
基金the financial support from National Natural Science Foundation of China(22363001,22378379,22479032,22022814)the National Key R&D Project(2022YFA1503900)+6 种基金the Natural Science Special Foundation of Guizhou University(No.202140)National Natural Science Foundation of China for Single-Atom Catalysis(22388102)the Youth Innovation Promotion Association CAS(Y2021057)Dalian Science Foundation for Distinguished Young Scholars(2021RJ10)Grant.YLU-DNL Fund(2022010)the Young Top-notch Talents of Liaoning Province(XLYC2203140)the Liaoning Foundation for Distinguished Young Scholars(2025JH6/101100011).
文摘UiO-66-H MOFs can effectively catalyze the direct selective oxidation of methane(DSOM)to high value-added oxygenates under mild conditions.However,UiO-66-NH_(2)with benzene-1,4-dicarboxylate(NH_(2)-BDC)ligand modifying the Zr-oxo nodes exhibits relatively inferior catalytic performance for DSOM.Here,a combination of density functional theory(DFT)calculations and experiments was employed to explore the underlying reasons for the limited catalytic activity of UiO-66-NH_(2).The results indicate that the methane hydroxylation performance of UiO-66-NH_(2)is almost unaffected by the increase of·OH concentration.This is attributed to the formation of substantial non-covalent hydrogen bonds between the oxygen atoms of oxygenic species on the Zr-oxo nodes and the hydrogen atoms of-NH_(2)groups,which diminishes the spin density distribution on the active sites of(·OH)m/UiO-66-NH_(2),leading to minimal change of the adsorption energy of CH_(4).Additionally,the calculated adsorption energies(Eads)of CH_(4)exhibit a linear relationship with the catalytic activity of UiO-66-NH_(2)for DSOM reaction.
基金supported by the Natural Science Foundation of Guangxi Province(2021GXNSFBA220077,GUIKE AD23026050)National Natural Science Foundation of China(22102035 and 22162006)Innovation Project of Guangxi Graduate Education(XYCBZ2024021).
文摘Chemical functionalization of graphene is a topic of paramount importance to broaden its applications in chemistry,physics,and biological science but remains a great challenge due to its low chemical activity and poor dispersion.Here,we report a strategy for the photosynergetic electrochemical functionalization of graphene(EFG).By using chloride ion(Cl^(-))as the intercalation anions and co-reactants,the electrogenerated radicals confined in the expanded graphite layers enable efficient radical addition reaction,thus grasping crystallineperfect EFG.We found that the ultraviolet irradiation and applied voltage have increased the surface/interface concentration of Cl,thus boosting the functionalization of graphene.Theoretical calculation and experimental results verified the oxygen evolution reaction(OER)on EFG has been improved by regulating the doping of chlorine atoms.In addition,the reduced interlayer distance and enhanced electrostatic repulsion near the basal plane endow the fabricated EFG-based membrane with high salt retention.This work highlights a method for the in situ functionalization of graphene and the subsequent applications in OER and water desalination.
文摘Organofluorines play a crucial role in medicine,agrochemicals,and materials science.Adding fluorine to molecules creates structures with specific beneficial properties or tunes properties through interactions with their environment.Many popular pharmaceuticals and agrochemicals contain fluorine because it enhances hydrogen bonding at protein’s active sites.
文摘Amino acids are the building blocks of proteins and play vital roles in both biological systems and drug development.In recent years,increasing attention has been given to the functionalization of amino acid derivatives.Since the introduction of therapeutic insulin in the early 20th century,the conjugation of drug molecules with amino acids and peptides has been pivotal in driving advancements in drug discovery and become an integral part of modern medical practice.Currently,over a hundred peptide-drug conjugates have received global approval and are widely used to treat diseases such as diabetes,cancer,chronic pain,and multiple sclerosis.Key technologies for conjugating peptides with bioactive molecules include antibody-drug conjugates(ADCs),peptide-drug conjugates(PDCs),and proteolysis targeting chimeras(PROTACs).Significant efforts have been dedicated to developing strategies for the modification of amino acids and peptides,with particular focus on site-selective C-H alkylation/arylation reactions.These reactions are crucial for synthesizing bioactive molecules,as they enable the precise introduction of functional groups at specific positions,thereby improving the pharmacological properties of the resulting compounds.
基金supported by National Natural Science Foundation of China (No. 51473095)the Program of Innovative Research Team for Young Scientists of Sichuan Province (2016TD0010)
文摘The synergistic effect of conventional flame-retardant elements and graphene has received extensive attention in the development of a new class of flame retardants. Compared to covalent modification, the noncovalent strategy is simpler and expeditious and entirely preserves the original quality of graphene. Thus, non-covalently functionalized graphene oxide(FGO) with a phosphorus–nitrogen compound was successfully prepared via a one-pot process in this study. Polyethyleneimine and FGO were alternatively deposited on the surface of a poly(vinyl alcohol)(PVA) film via layer-by-layer assembly driven by electrostatic interaction, imparting excellent flame retardancy to the coated PVA film. The multilayer FGO-based coating formed a protective shield encapsulating the PVA matrix, effectively blocking the transfer of heat and mass during combustion. The coated PVA has a higher initial decomposition temperature of about 260 °C and a nearly 60% reduction in total heat release than neat PVA does. Our results may have a promising prospect for flame-retardant polymers.
基金supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT)(No. 2021R1I1A1A0105621313, No. 2022R1F1A1074441, No. 2022K1A3A1A20014496, and No. 2022R1F1A1074083)supported by the Ministry of Education Funding (No. RIS 2021-004)supported by the Brain Pool program funded by the Ministry of Science and ICT through the National Research Foundation of Korea (RS-2023-00284318).
文摘In this study,precise control over the thickness and termination of Ti3C2TX MXene flakes is achieved to enhance their electrical properties,environmental stability,and gas-sensing performance.Utilizing a hybrid method involving high-pressure processing,stirring,and immiscible solutions,sub-100 nm MXene flake thickness is achieved within the MXene film on the Si-wafer.Functionalization control is achieved by defunctionalizing MXene at 650℃ under vacuum and H2 gas in a CVD furnace,followed by refunctionalization with iodine and bromine vaporization from a bubbler attached to the CVD.Notably,the introduction of iodine,which has a larger atomic size,lower electronegativity,reduce shielding effect,and lower hydrophilicity(contact angle:99°),profoundly affecting MXene.It improves the surface area(36.2 cm^(2) g^(-1)),oxidation stability in aqueous/ambient environments(21 days/80 days),and film conductivity(749 S m^(-1)).Additionally,it significantly enhances the gas-sensing performance,including the sensitivity(0.1119Ωppm^(-1)),response(0.2% and 23%to 50 ppb and 200 ppm NO_(2)),and response/recovery times(90/100 s).The reduced shielding effect of the–I-terminals and the metallic characteristics of MXene enhance the selectivity of I-MXene toward NO2.This approach paves the way for the development of stable and high-performance gas-sensing two-dimensional materials with promising prospects for future studies.
基金supported by the National Natural Science Foundation of China(Nos.52370110 and 21607044)supported by the Fundamental Research Funds for the Central Universities(No.2023MS146)the Open Research Fund of the School of Chemistry and Chemical Engineering,Henan Normal University for support(Nos.2020ZD01 and 2021YB07)。
文摘Mercury ion(Hg^(2+)),as one of the most toxic heavy metal ions,accumulates easily in the environment,which can generate potential hazards to the ecosystem and human health.To effectively detect and remove Hg^(2+),we fabricated four types of carbon dots(CDs)using carboxymethyl nanocellulose as a carbon source doped with different elements using a hydrothermal method.All the CDs exhibited a strong fluorescence emission,excitation-dependent emission and possessed good water dispersibility.Moreover,the four fluorescent CDs were used for Hg^(2+)recognition in aqueous solution,where the CDs-N exhibited better sensitivity and selectivity for Hg^(2+)detection,with a low limit of detection of 8.29×10^(-6)mol/L.It was determined that the fluorescence quenching could be ascribed to a photoinduced charge-transfer processes between Hg^(2+)and the CDs.In addition,the CDs-N were used as a smart invisible ink for anticounterfeiting,information encryption and decryption.Furthermore,the CDs-N were immersed into a cellulose(CMC)-based hydrogel network to prepare fluorescent hydrogels capable of simultaneously detecting and adsorbing Hg^(2+).We anticipate that this research will open possibilities for a green method to synthesize fluorescent CDs for metal ion detection and fluorescent ink production.
基金supported in part by NIH R01 NS100531,R01 NS103481NIH R21NS130241(to LD)+3 种基金Merit Review Award I01 BX002356,I01 BX003705 from the U.S.Department of Veterans AffairsIndiana Spinal Cord and Brain Injury Research Foundation(No.19919)Mari Hulman George Endowment Funds(to XMX)Indiana Spinal Cord&Brain Injury Research Fund from ISDH(to NKL and LD)。
文摘Schwann cell transplantation is considered one of the most promising cell-based therapy to repair injured spinal cord due to its unique growth-promoting and myelin-forming properties.A the Food and Drug Administration-approved Phase I clinical trial has been conducted to evaluate the safety of transplanted human autologous Schwann cells to treat patients with spinal cord injury.A major challenge for Schwann cell transplantation is that grafted Schwann cells are confined within the lesion cavity,and they do not migrate into the host environment due to the inhibitory barrier formed by injury-induced glial scar,thus limiting axonal reentry into the host spinal cord.Here we introduce a combinatorial strategy by suppressing the inhibitory extracellular environment with injection of lentivirus-mediated transfection of chondroitinase ABC gene at the rostral and caudal borders of the lesion site and simultaneously leveraging the repair capacity of transplanted Schwann cells in adult rats following a mid-thoracic contusive spinal cord injury.We report that when the glial scar was degraded by chondroitinase ABC at the rostral and caudal lesion borders,Schwann cells migrated for considerable distances in both rostral and caudal directions.Such Schwann cell migration led to enhanced axonal regrowth,including the serotonergic and dopaminergic axons originating from supraspinal regions,and promoted recovery of locomotor and urinary bladder functions.Importantly,the Schwann cell survival and axonal regrowth persisted up to 6 months after the injury,even when treatment was delayed for 3 months to mimic chronic spinal cord injury.These findings collectively show promising evidence for a combinatorial strategy with chondroitinase ABC and Schwann cells in promoting remodeling and recovery of function following spinal cord injury.
基金supported by the National Natural Science Foundation of China,Nos.82204360(to HM)and 82270411(to GW)National Science and Technology Innovation 2030 Major Program,No.2021ZD0200900(to YL)。
文摘Traumatic brain injury involves complex pathophysiological mechanisms,among which oxidative stress significantly contributes to the occurrence of secondary injury.In this study,we evaluated hypidone hydrochloride(YL-0919),a self-developed antidepressant with selective sigma-1 receptor agonist properties,and its associated mechanisms and targets in traumatic brain injury.Behavioral experiments to assess functional deficits were followed by assessment of neuronal damage through histological analyses and examination of blood-brain barrier permeability and brain edema.Next,we investigated the antioxidative effects of YL-0919 by assessing the levels of traditional markers of oxidative stress in vivo in mice and in vitro in HT22 cells.Finally,the targeted action of YL-0919 was verified by employing a sigma-1 receptor antagonist(BD-1047).Our findings demonstrated that YL-0919 markedly improved deficits in motor function and spatial cognition on day 3 post traumatic brain injury,while also decreasing neuronal mortality and reversing blood-brain barrier disruption and brain edema.Furthermore,YL-0919 effectively combated oxidative stress both in vivo and in vitro.The protective effects of YL-0919 were partially inhibited by BD-1047.These results indicated that YL-0919 relieved impairments in motor and spatial cognition by restraining oxidative stress,a neuroprotective effect that was partially reversed by the sigma-1 receptor antagonist BD-1047.YL-0919 may have potential as a new treatment for traumatic brain injury.
