α-Trifluoromethyl ketones are a class of useful compounds with versatile applications.Their synthetic application via the transformation of the C—F bonds is of particular interest by allowing the synthesis of organi...α-Trifluoromethyl ketones are a class of useful compounds with versatile applications.Their synthetic application via the transformation of the C—F bonds is of particular interest by allowing the synthesis of organic compounds with diverse structures.Herein,the advances in the research areas ofα-trifluoromethyl ketone synthesis and their defluorination reactions are reviewed.Discussion on the mechanisms of the typical reactions has also been provided,in hope of affording some guides to the chemistry ofα-trifluoromethyl ketones in the synthetic methods toward themselves and their derivatives.展开更多
3-Deoxy-D-manno–oct-2-ulosonic acid(Kdo)is widely distributed in bacteria,and the synthesis of Kdocontaining oligosaccharides is important for the development of novel antibiotics and immunological agents.We have rec...3-Deoxy-D-manno–oct-2-ulosonic acid(Kdo)is widely distributed in bacteria,and the synthesis of Kdocontaining oligosaccharides is important for the development of novel antibiotics and immunological agents.We have recently developed a strategy to achieveα-stereocontrolled glycosylation using a C3-p-tolylthio-substituted Kdo phosphite donor.The wide substrate scope and high reactivity of the donors enabled the efficient synthesis of a series of Kdo-containing glycosides with completeα-stereoselectivity and without the formation of 2,3-ene byproducts.In this study,we improved the method by replacing the leaving group diethyl phosphite with fluoride,which enhanced the stability of the donor and led to cleaner reaction.Furthermore,the substrate range was expanded by synthesizing a series of Kdo O/C/S/Nglycosides,which also opened up a new avenue for the synthesis of CMP-Kdo synthase inhibitors.展开更多
Planar chiral cyclophanes are a type of structurally intriguing organic molecules,which have found increasingly applications in the field of biologically active compounds,asymmetric catalysis,and optically pure materi...Planar chiral cyclophanes are a type of structurally intriguing organic molecules,which have found increasingly applications in the field of biologically active compounds,asymmetric catalysis,and optically pure materials.As such,significant efforts in the development of new methods to build up enantioenriched cyclophanes in a precise manner have attracted increased attention in recent years.Among the plethora of reported synthetic strategies,catalytic enantioselective method has emerged as one of the most straightforward and efficient ways to deliver optically pure planar chiral cyclophanes.In this review,the recent progress in catalytic enantioselective reactions for the synthesis of planar chiral cyclophanes will be discussed,which would stimulate the research interest of chemists for the discovery of novel asymmetric strategies for the preparation of valuable and previously difficult-to-access chiral molecules.展开更多
The transition metal-free chalcogen trifluoromethylation of alkenes represents a highly efficient transformation for the rapid generation of C(sp3)-rich aliphatic trifluoromethyl compounds. However, a unified methodol...The transition metal-free chalcogen trifluoromethylation of alkenes represents a highly efficient transformation for the rapid generation of C(sp3)-rich aliphatic trifluoromethyl compounds. However, a unified methodology to achieve oxy-, thio-, and seleno-trifluoromethylation remains elusive yet highly desirable. In this study, we report a triarylamine-catalyzed three-component vicinal chalcogen-trifluoromethylation of alkenes under blue light irradiation without the need of transition metal catalyst. This reaction is broadly applicable to oxy, thio, and seleno nucleophiles, facilitating modular access to a diverse array of β-trifluoromethyl alcohols, ethers, thioethers, thiocyanates, and selenocyanates with good yields and predictable regioselectivities (61 examples). Additionally, we demonstrate its application in the late-stage modification of natural products and pharmaceutical compounds. Preliminary mechanistic studies suggest that a catalytic electron donor-acceptor (EDA) complex between triarylamine and the Umemoto reagent is key to enabling the radical/polar crossover process.展开更多
The synthesis of fused arenes from non-aromatic precursors is useful but challenging.Herein,the synthesis of widely-used naphthylamines was focused.The three-component reactions of p-quinols,enals and amines were inve...The synthesis of fused arenes from non-aromatic precursors is useful but challenging.Herein,the synthesis of widely-used naphthylamines was focused.The three-component reactions of p-quinols,enals and amines were investigated under the dienamine/iminium-based dual organocatalysis.The efficient synthesis of naphthylamines was achieved via a formal[3+3]cyclization of the amines activated p-quinols and enals,with the following Bu_(4)NOAc/AgNO_(3) facilitated dual aromatization.The different reactivity of in-situ generated dienamine and iminium intermediates resulted in the differentiating catalysis,providing an efficient and practical methodology for the synthesis of fused arenes from non-aromatic precursors.展开更多
Polycyclic compounds are widely found in natural products and drug molecules with important biological activities,which attracted the attention of many chemists.Phosphine-catalyzed nucleophilic addition is one of the ...Polycyclic compounds are widely found in natural products and drug molecules with important biological activities,which attracted the attention of many chemists.Phosphine-catalyzed nucleophilic addition is one of the most powerful tools for the construction of various cyclic compounds with the advantages of atom economy,mild reaction conditions and simplicity of operation.Allenolates,Morita−Baylis−Hillman(MBH)alcohols and their derivatives(MBHADs),electron-deficient olefins and alkynes are very efficient substrates in phosphine mediated annulations,which formed many phosphonium species such asβ-phosphonium enolates,β-phosphonium dienolates and vinyl phosphonium ylides as intermediates.This review describes the reactivities of these phosphonium zwitterions and summarizes the synthesis of polycycle compounds through phosphine-mediated intramolecular and intermolecular sequential annulations.Thus,a systematic summary of the research process based on the phosphine-mediated sequential annulations of allenolates,MBH alcohols and MBHADs,electron-deficient olefins and alkynes are presented in Chapters 2-6,respectively.展开更多
1-Isoquinolin-1(2H)-one skeleton exists widely in natural products,pharmaceuticals and materials.We disclose here a fluorine effect and catalyst cooperatively induced regioselective or regiospecific 3,4-functionalizat...1-Isoquinolin-1(2H)-one skeleton exists widely in natural products,pharmaceuticals and materials.We disclose here a fluorine effect and catalyst cooperatively induced regioselective or regiospecific 3,4-functionalization of unsymmetric 2-CF_(3)-1,3-enynes.The presence of trifluoromethyl group is determinable for the regioselectivity.When the CF_(3) group was replaced with the methyl or amide group,the regioselectivity decreased to a ratio of 1.3:1 or 1:1.7,respectively.For alkyl substitutedβ-CF_(3)-1,3-enynes,a regiospecificity was obtained.This strategy features excellent regioselectivity,broad substrate scope and high functional group tolerance.Mechanistic studies showed that C–H bond activation is the rate-limiting step.展开更多
Whether environmental regulation can increase employment is still controversial in academic circles around the world.An important reason lies in the validity of an empirical method.Using China’s inter-provincial pane...Whether environmental regulation can increase employment is still controversial in academic circles around the world.An important reason lies in the validity of an empirical method.Using China’s inter-provincial panel data from 2003 to 2015 and the synthetic control method(SCM),this paper focuses on a test that was carried out on the basis of a quasi-natural experiment of the 2007 Emission Trading Pilot(ETP)policy.The test results show that the ETP policy has increased the average employment level by 3.25 percentage points and passed a robustness test.The robustness test using the regression control method(RCM)shows that the average employment level has risen by 3.21 percentage points.This means that the ETP policy has significantly increased employment.The paper also puts forward three policy recommendations:optimizing the trading system for emissions rights,encouraging companies to carry out cleaner production and innovation,and incorporating environmental performance assessments.展开更多
Ceria nanoparticles(CeO_(2) NPs)have become popular materials in biomedical and industrial fields due to their potential applications in anti-oxidation,cancer therapy,photocatalytic degradation of pollutants,sensors,e...Ceria nanoparticles(CeO_(2) NPs)have become popular materials in biomedical and industrial fields due to their potential applications in anti-oxidation,cancer therapy,photocatalytic degradation of pollutants,sensors,etc.Many methods,including gas phase,solid phase,liquid phase,and the newly proposed green synthesis method,have been reported for the synthesis of CeO_(2) NPs.Due to the wide application of CeO_(2) NPs,concerns about their adverse impacts on human health have been raised.This review covers recent studies on the biomedical applications of CeO_(2) NPs,including their use in the treatment of various diseases(e.g.,Alzheimer's disease,ischemic stroke,retinal damage,chronic inflammation,and cancer).CeO_(2) NP toxicity is discussed in terms of the different systems of the human body(e.g.,cytotoxicity,genotoxicity,respiratory toxicity,neurotoxicity,and hepatotoxicity).This comprehensive review covers both fundamental discoveries and exploratory progress in CeO_(2) NP research that may lead to practical developments in the future.展开更多
Supercapacitors(SCs)have remarkable energy storage capabilities and have garnered considerable interest due to their superior power densities and ultra-long cycling characteristics.However,their comparatively low ener...Supercapacitors(SCs)have remarkable energy storage capabilities and have garnered considerable interest due to their superior power densities and ultra-long cycling characteristics.However,their comparatively low energy density limits their extensive application in large-scale commercial applications.Electrode materials directly affect the performance of SCs.Thus,the development of cutting-edge electrode materials and modification of their morphological and structural properties are vital for advancing the performance of SCs.Transition metal compounds have a high specific capacity and good cycling durability,making them the most promising electrode active materials for high-energy density SCs.Nevertheless,their inadequate conductivity,unfavorable ion diffusion rates,substantial volume expansion and phase transitions during charging and discharging are obstacles to their stable and efficient integration into SCs.To address these challenges,this study provides a comprehensive summary of the current advancements in transition metal nanomaterials as electrode materials for SCs,an overview of the current research status,and the prevailing challenges.Furthermore,this study highlights synthetic techniques and management strategies for electrode materials derived from transition metal compounds,targeting the resolution of the aforementioned challenges.Finally,a concise discussion is provided on the future directions of SC development,with an emphasis on the utilization of transition metal compound electrode materials.展开更多
Sunlight-driven photocatalysis,which can produce clean fuels and mitigate environmental pollution,has received extensive research attention due to its potential for addressing both energy shortages and environmental c...Sunlight-driven photocatalysis,which can produce clean fuels and mitigate environmental pollution,has received extensive research attention due to its potential for addressing both energy shortages and environmental crises.Bismuth(Bi)-based photocatalysts with broad spectrum solar-light absorption and tunable structures,exhibit promising applications in solar-driven photocatalysis.Oxygen vacancy(OV)engineering is a widely recognized strategy that shows great potential for accelerating charge separation and small molecule activation.Based on OV engineering,this review focuses on Bi-based photocatalysts and provides a comprehensive overview including synthetic methods,regulation strategies,and applications in photocatalytic field.The synthetic methods of Bibased photocatalysts with OVs(BPOVs)are classified into hydrothermal,solvothermal,ultraviolet light reduction,calcination,chemical etching,and mechanical methods based on different reaction types,which provide the possibility for the structural regulation of BPOVs,including dimensional regulation,vacancy creation,elemental doping,and heterojunction fabrication.Furthermore,this review also highlights the photocatalytic applications of BPOVs,including CO_(2)reduction,N2 fixation,H2 generation,O_(2)evolution,pollutant degradation,cancer therapy,and bacteria inactivation.Finally,the conclusion and prospects toward the future development of BPOVs photocatalysts are presented.展开更多
5-amino-4-nitrobenzo[1,2-c:3,4-c']bis([1,2,5]oxadiazole)1,6-dioxide(CL-18)exhibits significant potential as an initiating explosive.However,its current synthesis process remains non-scalable due to low yields and ...5-amino-4-nitrobenzo[1,2-c:3,4-c']bis([1,2,5]oxadiazole)1,6-dioxide(CL-18)exhibits significant potential as an initiating explosive.However,its current synthesis process remains non-scalable due to low yields and safety risks.In this study,we have developed a simple and safe synthetic route for CL-18.It was synthesized from 3,5-dihaloanisole in a four-step reaction with an overall yield exceeding 60%,surpassing all reported yields in the literature.Subsequently,recrystallization of CL-18 was successfully achieved by carefully selecting appropriate solvents and antisolvents to reduce its mechanical sensitivity.Ultimately,when DMF-ethanol was employed as the recrystallization solvent system,satisfactory product yield(>90%)and reduced mechanical sensitivity(IS=15 J;FS=216 N)were obtained.Additionally,CL-18 is derived from the rearrangement of oxygen atoms on i-CL-18 furoxan,and a comparative analysis of their physicochemical properties was conducted.The thermal stability of both compounds is similar,with onset decomposition temperatures recorded at 186 and 182℃respectively.Similarly,they exhibit 5 s breaking point temperatures of 236 and 237℃.Additionally,we present novel insights into the positional-isomerization-laser-ignition performance of CL-18 and its isomer i-CL-18 using laser irradiation for the first time.Remarkably,our findings demonstrate that i-CL-18 exhibits enhanced laser sensitivity,as it can be directly ignited by a 1064 nm wavelength laser,whereas CL-18 lacks this characteristic.展开更多
COVID-19 is a major event with worldwide influences.Since the beginning of the epidemic,pharmaceutical chemists have paid attention to the therapeutic effect of a variety of small molecule medicines on COVID-19 infect...COVID-19 is a major event with worldwide influences.Since the beginning of the epidemic,pharmaceutical chemists have paid attention to the therapeutic effect of a variety of small molecule medicines on COVID-19 infection.A series of organic molecules are designed and found to be effective in the treatment of COVID-19 infection.In fact,no matter how effective they are,with the development of the COVID-19 epidemic,various small molecule medicines are gradually recognized by people.This is equivalent to a good science popularization of pharmaceutical chemistry.This review aims to introduce the molecules for COVID-19 treatment on the basis of their chemical structures,synthetic methods as well as their effects.展开更多
The entry of collective construction land for business purposes is an important measure for deepening the reform of the rural land system,promoting the flow of urban and rural factors,and realizing rural revitalizatio...The entry of collective construction land for business purposes is an important measure for deepening the reform of the rural land system,promoting the flow of urban and rural factors,and realizing rural revitalization.Since the production of the first batch of pilot projects in 2015,33 county-level cities have participated in the pilot policy by 2023.Deqing County,Zhejiang Province,as the first area to participate in the pilot project,aims to achieve more fruitful results.This paper first examines how promoting farmers’income through the market entry of agricultural land can be achieved,then uses the synthetic control method to quantitatively study the impact of collective operational construction land on farmers’income using panel data from 2011 to 2019,and finally proposes relevant suggestions from the perspective of system reform.展开更多
In order to suppress the airwave noise in marine controlled-source electromagnetic （CSEM） data, we propose a 3D deconvolution （3DD） interferometry method with a synthetic aperture source and obtain the relative an...In order to suppress the airwave noise in marine controlled-source electromagnetic （CSEM） data, we propose a 3D deconvolution （3DD） interferometry method with a synthetic aperture source and obtain the relative anomaly coefficient （RAC） of the EM field reflection responses to show the degree for suppressing the airwave. We analyze the potential of the proposed method for suppressing the airwave, and compare the proposed method with traditional methods in their effectiveness. A method to select synthetic source length is derived and the effect of the water depth on RAC is examined via numerical simulations. The results suggest that 3DD interferometry method with a synthetic source can effectively suppress the airwave and enhance the potential of marine CSEM to hydrocarbon exploration.展开更多
Lithium-sulfur(Li-S)batteries,although a promising candidate of next-generation energy storage devices,are hindered by some bottlenecks in their roadmap toward commercialization.The key challenges include solving the ...Lithium-sulfur(Li-S)batteries,although a promising candidate of next-generation energy storage devices,are hindered by some bottlenecks in their roadmap toward commercialization.The key challenges include solving the issues such as low utilization of active materials,poor cyclic stability,poor rate performance,and unsatisfactory Coulombic efficiency due to the inherent poor electrical and ionic conductivity of sulfur and its discharged products(e.g.,Li2S2 and Li_(2)S),dissolution and migration of polysulfide ions in the electrolyte,unstable solid electrolyte interphase and dendritic growth on an odes,and volume change in both cathodes and anodes.Owing to the high specific surface area,pore volume,low density,good chemical stability,and particularly multimodal pore sizes,hierarchical porous carbon(HPC)mate rials have received considerable attention for circumventing the above pro blems in Li-S batteries.Herein,recent progress made in the synthetic methods and deployment of HPC materials for various components including sulfur cathodes,separators and interlayers,and lithium anodes in Li-S batteries is presented and summarized.More importantly,the correlation between the structures(pore volume,specific surface area,degree of pores,and heteroatom-doping)of HPC and the electrochemical performances of Li-S batteries is elaborated.Finally,a discussion on the challenges and future perspectives associated with HPCs for Li-S batteries is provided.展开更多
In recent years,an increasing amount of interest has been dedicated to the synthesis and application of ZIF-67-based materials due to their exceptionally high surface area,tunable porosity,and excellent thermal and ch...In recent years,an increasing amount of interest has been dedicated to the synthesis and application of ZIF-67-based materials due to their exceptionally high surface area,tunable porosity,and excellent thermal and chemical stabilities.This review summarizes the latest strategies of synthesizing ZIF-67-based materials by exploring the prominent examples.Then,the recent progress in the applications of ZIF-67-based materials in heterogeneous catalysis,including catalysis of the redox reactions,addition reactions,esterification reactions,Knoevenagel condensations,and hydrogenation-dehydrogenation reactions,has been elaborately discussed.Finally,we end this work by shedding some light on the large-scale industrial production of ZIF-67-based materials and their applications in the future.展开更多
Three-dimensional graphene/conducting polymer（3DGCP） composites have received significant attention in recent years due to their unique structures and promising applications in energy storage.With the structural div...Three-dimensional graphene/conducting polymer（3DGCP） composites have received significant attention in recent years due to their unique structures and promising applications in energy storage.With the structural diversity of graphene and π-functional conducting polymers via rich chemical routes,a number of 3DGCP composites with novel structures and attractive performance have been developed.Particularly,the hierarchical porosity,the interactions between graphene and conducting polymers as well as the their synergetic effects within 3DGCP composites can be well combined and elaborated by various synthetic methods,which made 3DGCP composites show unique electrochemical properties and significantly improved performance in energy storage fields compared to other graphenebased composites.In this short review,we present recent advances in 3DGCP composites in developing effective strategies to prepare 3DGCP composites and exploring them as a unique platform for supercapacitors with unprecedented performance.The challenges and future opportunities are also discussed for promotion of further study.展开更多
The synthetic routes of porous carbons and the applications of the functional porous carbon-based composite electrode materials for lithium secondary batteries are reviewed. The synthetic methods have made great break...The synthetic routes of porous carbons and the applications of the functional porous carbon-based composite electrode materials for lithium secondary batteries are reviewed. The synthetic methods have made great breakthroughs to control the pore size and volume, wall thickness, surface area, and connectivity of porous carbons, which result in the development of functional porous carbon-based composite electrode materials. The effects of porous carbons on the electrochemical properties are further discussed. The porous carbons as ideal matrixes to incorporate active materials make a great improvement on the electrochemical properties because of high surface area and pore volume, excellent electronic conductivity, and strong adsorption capacity. Large numbers of the composite electrode materials have been used for the devices of electrochemical energy conversion and storage, such as lithium-ion batteries （LIBs）, Li-S batteries, and Li-O2 batteries. It is believed that functional porous carbon-based composite electrode materials will continuously contribute to the field of lithium secondary batteries.展开更多
The exploration of lightweight and efficient electromagnetic wave(EMW)absorption materials is a crucial focus topic because the human body and precision instruments are exposed to the increasingly serious electromagne...The exploration of lightweight and efficient electromagnetic wave(EMW)absorption materials is a crucial focus topic because the human body and precision instruments are exposed to the increasingly serious electromagnetic pollution.Ferrite,as the first type of EMW absorption material,is still the indelible superstar in the EMW absorption field due to its unique double loss mechanism,controllable morphology and high permeability.This review briefly introduces the EMW absorption and attenuation mechanism of ferrite-based composite absorbers,including dielectric loss dominated by charge transfer and polarization relaxation,and magnetic loss consisted of eddy current and resonance.Moreover,we comb the advances in synthesis of ferrite materials.In particular,this paper summarizes the advantages and defects of pure ferrite as EMW absorption material.And the approach to tackling the imbalance of impedance matching and highdensity in ferrite is also reviewed,including ion substitution,design of micro-morphology and doping with dielectric loss materials.展开更多
文摘α-Trifluoromethyl ketones are a class of useful compounds with versatile applications.Their synthetic application via the transformation of the C—F bonds is of particular interest by allowing the synthesis of organic compounds with diverse structures.Herein,the advances in the research areas ofα-trifluoromethyl ketone synthesis and their defluorination reactions are reviewed.Discussion on the mechanisms of the typical reactions has also been provided,in hope of affording some guides to the chemistry ofα-trifluoromethyl ketones in the synthetic methods toward themselves and their derivatives.
基金supported by the National Key R&D Program of China(Nos.2022YFF1203005,2022YFC2303700)supported by the National Natural Science Foundation of China(Nos.81930097,82151223).
文摘3-Deoxy-D-manno–oct-2-ulosonic acid(Kdo)is widely distributed in bacteria,and the synthesis of Kdocontaining oligosaccharides is important for the development of novel antibiotics and immunological agents.We have recently developed a strategy to achieveα-stereocontrolled glycosylation using a C3-p-tolylthio-substituted Kdo phosphite donor.The wide substrate scope and high reactivity of the donors enabled the efficient synthesis of a series of Kdo-containing glycosides with completeα-stereoselectivity and without the formation of 2,3-ene byproducts.In this study,we improved the method by replacing the leaving group diethyl phosphite with fluoride,which enhanced the stability of the donor and led to cleaner reaction.Furthermore,the substrate range was expanded by synthesizing a series of Kdo O/C/S/Nglycosides,which also opened up a new avenue for the synthesis of CMP-Kdo synthase inhibitors.
基金financial support provided by Huanghuai University and Hangzhou Medical College.
文摘Planar chiral cyclophanes are a type of structurally intriguing organic molecules,which have found increasingly applications in the field of biologically active compounds,asymmetric catalysis,and optically pure materials.As such,significant efforts in the development of new methods to build up enantioenriched cyclophanes in a precise manner have attracted increased attention in recent years.Among the plethora of reported synthetic strategies,catalytic enantioselective method has emerged as one of the most straightforward and efficient ways to deliver optically pure planar chiral cyclophanes.In this review,the recent progress in catalytic enantioselective reactions for the synthesis of planar chiral cyclophanes will be discussed,which would stimulate the research interest of chemists for the discovery of novel asymmetric strategies for the preparation of valuable and previously difficult-to-access chiral molecules.
基金the financial support provided by the National Natural Science Foundation of China(22361142832,92156025,22271212)the Science and Technology Project of Hebei Education Department Foundation(BJ2025192)We would like to thank Dr.Guosheng Ding,Dr.Kongying Zhu,and Dr.Xiaojuan Deng at the Analysis and Testing Center of Tianjin University for their assistance with NMR testing and analysis.
文摘The transition metal-free chalcogen trifluoromethylation of alkenes represents a highly efficient transformation for the rapid generation of C(sp3)-rich aliphatic trifluoromethyl compounds. However, a unified methodology to achieve oxy-, thio-, and seleno-trifluoromethylation remains elusive yet highly desirable. In this study, we report a triarylamine-catalyzed three-component vicinal chalcogen-trifluoromethylation of alkenes under blue light irradiation without the need of transition metal catalyst. This reaction is broadly applicable to oxy, thio, and seleno nucleophiles, facilitating modular access to a diverse array of β-trifluoromethyl alcohols, ethers, thioethers, thiocyanates, and selenocyanates with good yields and predictable regioselectivities (61 examples). Additionally, we demonstrate its application in the late-stage modification of natural products and pharmaceutical compounds. Preliminary mechanistic studies suggest that a catalytic electron donor-acceptor (EDA) complex between triarylamine and the Umemoto reagent is key to enabling the radical/polar crossover process.
基金the Department of Science and Technology of Jilin Province(20220402046GH,20220101066JC)Research Projects from Education Department of Jilin Province(JJKH20250313BS)are greatly acknowledged.
文摘The synthesis of fused arenes from non-aromatic precursors is useful but challenging.Herein,the synthesis of widely-used naphthylamines was focused.The three-component reactions of p-quinols,enals and amines were investigated under the dienamine/iminium-based dual organocatalysis.The efficient synthesis of naphthylamines was achieved via a formal[3+3]cyclization of the amines activated p-quinols and enals,with the following Bu_(4)NOAc/AgNO_(3) facilitated dual aromatization.The different reactivity of in-situ generated dienamine and iminium intermediates resulted in the differentiating catalysis,providing an efficient and practical methodology for the synthesis of fused arenes from non-aromatic precursors.
基金the National Natural Science Foundation of China(Nos.22171147 and 21871148)for the financial support。
文摘Polycyclic compounds are widely found in natural products and drug molecules with important biological activities,which attracted the attention of many chemists.Phosphine-catalyzed nucleophilic addition is one of the most powerful tools for the construction of various cyclic compounds with the advantages of atom economy,mild reaction conditions and simplicity of operation.Allenolates,Morita−Baylis−Hillman(MBH)alcohols and their derivatives(MBHADs),electron-deficient olefins and alkynes are very efficient substrates in phosphine mediated annulations,which formed many phosphonium species such asβ-phosphonium enolates,β-phosphonium dienolates and vinyl phosphonium ylides as intermediates.This review describes the reactivities of these phosphonium zwitterions and summarizes the synthesis of polycycle compounds through phosphine-mediated intramolecular and intermolecular sequential annulations.Thus,a systematic summary of the research process based on the phosphine-mediated sequential annulations of allenolates,MBH alcohols and MBHADs,electron-deficient olefins and alkynes are presented in Chapters 2-6,respectively.
基金supported by National Natural Science Founda:tion of China(22461002,22308061,22305046)Natural Science Foundation(NSF)of Jiangxi Province(20224BAB213011,20242BAB20110,20224BAB213012)+1 种基金High-Level and Highly Demanded Overseas Talent Programs of Jiangxi Province(20232BCJ25050)Gannan Normal University Start-up Fund(BSJJ202109).
文摘1-Isoquinolin-1(2H)-one skeleton exists widely in natural products,pharmaceuticals and materials.We disclose here a fluorine effect and catalyst cooperatively induced regioselective or regiospecific 3,4-functionalization of unsymmetric 2-CF_(3)-1,3-enynes.The presence of trifluoromethyl group is determinable for the regioselectivity.When the CF_(3) group was replaced with the methyl or amide group,the regioselectivity decreased to a ratio of 1.3:1 or 1:1.7,respectively.For alkyl substitutedβ-CF_(3)-1,3-enynes,a regiospecificity was obtained.This strategy features excellent regioselectivity,broad substrate scope and high functional group tolerance.Mechanistic studies showed that C–H bond activation is the rate-limiting step.
文摘Whether environmental regulation can increase employment is still controversial in academic circles around the world.An important reason lies in the validity of an empirical method.Using China’s inter-provincial panel data from 2003 to 2015 and the synthetic control method(SCM),this paper focuses on a test that was carried out on the basis of a quasi-natural experiment of the 2007 Emission Trading Pilot(ETP)policy.The test results show that the ETP policy has increased the average employment level by 3.25 percentage points and passed a robustness test.The robustness test using the regression control method(RCM)shows that the average employment level has risen by 3.21 percentage points.This means that the ETP policy has significantly increased employment.The paper also puts forward three policy recommendations:optimizing the trading system for emissions rights,encouraging companies to carry out cleaner production and innovation,and incorporating environmental performance assessments.
基金supported by the National Natural Science Foundation of China(Nos.32161143035 and 81970826)the Yantai Science and Technology Innovation Development Plan(No.2022XDRH033),China。
文摘Ceria nanoparticles(CeO_(2) NPs)have become popular materials in biomedical and industrial fields due to their potential applications in anti-oxidation,cancer therapy,photocatalytic degradation of pollutants,sensors,etc.Many methods,including gas phase,solid phase,liquid phase,and the newly proposed green synthesis method,have been reported for the synthesis of CeO_(2) NPs.Due to the wide application of CeO_(2) NPs,concerns about their adverse impacts on human health have been raised.This review covers recent studies on the biomedical applications of CeO_(2) NPs,including their use in the treatment of various diseases(e.g.,Alzheimer's disease,ischemic stroke,retinal damage,chronic inflammation,and cancer).CeO_(2) NP toxicity is discussed in terms of the different systems of the human body(e.g.,cytotoxicity,genotoxicity,respiratory toxicity,neurotoxicity,and hepatotoxicity).This comprehensive review covers both fundamental discoveries and exploratory progress in CeO_(2) NP research that may lead to practical developments in the future.
基金supported by the National Natural Science Foundation of China(No.22301151)the Natural Science Foundation of Inner Mongolia Autonomous Region of China(No.2022QN05024)+3 种基金the Fundamental Scientific Research Funds for Universities directly under Inner Mongolia Autonomous Region of China(Nos.JY20230097 and JY20220116)the Program for Innovative Research Team in Universities of Inner Mongolia Autonomous Region(No.NMGIRT2211)Inner Mongolia University of Technology Key Discipline Team Project of Materials Science(No.ZD202012)the Young Leading Talent of“Grassland Talents”Project of Inner Mongolia Autonomous Region(No.QNLJ012010)。
文摘Supercapacitors(SCs)have remarkable energy storage capabilities and have garnered considerable interest due to their superior power densities and ultra-long cycling characteristics.However,their comparatively low energy density limits their extensive application in large-scale commercial applications.Electrode materials directly affect the performance of SCs.Thus,the development of cutting-edge electrode materials and modification of their morphological and structural properties are vital for advancing the performance of SCs.Transition metal compounds have a high specific capacity and good cycling durability,making them the most promising electrode active materials for high-energy density SCs.Nevertheless,their inadequate conductivity,unfavorable ion diffusion rates,substantial volume expansion and phase transitions during charging and discharging are obstacles to their stable and efficient integration into SCs.To address these challenges,this study provides a comprehensive summary of the current advancements in transition metal nanomaterials as electrode materials for SCs,an overview of the current research status,and the prevailing challenges.Furthermore,this study highlights synthetic techniques and management strategies for electrode materials derived from transition metal compounds,targeting the resolution of the aforementioned challenges.Finally,a concise discussion is provided on the future directions of SC development,with an emphasis on the utilization of transition metal compound electrode materials.
基金This work was financially supported by the National Natural Science Foundation of China(NSFC)(No.22308336)the City University of Hong Kong start-up fund.
文摘Sunlight-driven photocatalysis,which can produce clean fuels and mitigate environmental pollution,has received extensive research attention due to its potential for addressing both energy shortages and environmental crises.Bismuth(Bi)-based photocatalysts with broad spectrum solar-light absorption and tunable structures,exhibit promising applications in solar-driven photocatalysis.Oxygen vacancy(OV)engineering is a widely recognized strategy that shows great potential for accelerating charge separation and small molecule activation.Based on OV engineering,this review focuses on Bi-based photocatalysts and provides a comprehensive overview including synthetic methods,regulation strategies,and applications in photocatalytic field.The synthetic methods of Bibased photocatalysts with OVs(BPOVs)are classified into hydrothermal,solvothermal,ultraviolet light reduction,calcination,chemical etching,and mechanical methods based on different reaction types,which provide the possibility for the structural regulation of BPOVs,including dimensional regulation,vacancy creation,elemental doping,and heterojunction fabrication.Furthermore,this review also highlights the photocatalytic applications of BPOVs,including CO_(2)reduction,N2 fixation,H2 generation,O_(2)evolution,pollutant degradation,cancer therapy,and bacteria inactivation.Finally,the conclusion and prospects toward the future development of BPOVs photocatalysts are presented.
基金support from the National Natural Science Foundation of China(Grant No.22175160)the Science Challenge Project(Grant No.TZ2018004)。
文摘5-amino-4-nitrobenzo[1,2-c:3,4-c']bis([1,2,5]oxadiazole)1,6-dioxide(CL-18)exhibits significant potential as an initiating explosive.However,its current synthesis process remains non-scalable due to low yields and safety risks.In this study,we have developed a simple and safe synthetic route for CL-18.It was synthesized from 3,5-dihaloanisole in a four-step reaction with an overall yield exceeding 60%,surpassing all reported yields in the literature.Subsequently,recrystallization of CL-18 was successfully achieved by carefully selecting appropriate solvents and antisolvents to reduce its mechanical sensitivity.Ultimately,when DMF-ethanol was employed as the recrystallization solvent system,satisfactory product yield(>90%)and reduced mechanical sensitivity(IS=15 J;FS=216 N)were obtained.Additionally,CL-18 is derived from the rearrangement of oxygen atoms on i-CL-18 furoxan,and a comparative analysis of their physicochemical properties was conducted.The thermal stability of both compounds is similar,with onset decomposition temperatures recorded at 186 and 182℃respectively.Similarly,they exhibit 5 s breaking point temperatures of 236 and 237℃.Additionally,we present novel insights into the positional-isomerization-laser-ignition performance of CL-18 and its isomer i-CL-18 using laser irradiation for the first time.Remarkably,our findings demonstrate that i-CL-18 exhibits enhanced laser sensitivity,as it can be directly ignited by a 1064 nm wavelength laser,whereas CL-18 lacks this characteristic.
基金Natural Science Foundation of Hubei Province(No.2022CFB008)the Open Fund Project of Hubei Key Laboratory of Radiation Chemistry and Functional Materials(No.2021KF07)+1 种基金the fund of the joint-laboratory of Shanghai Dingya Pharmaceutical Chemical Technology Co.,Ltd.with Yangzhou University(2022-2027)Priority Academic Program Development of Jiangsu Higher Education Institution for support。
文摘COVID-19 is a major event with worldwide influences.Since the beginning of the epidemic,pharmaceutical chemists have paid attention to the therapeutic effect of a variety of small molecule medicines on COVID-19 infection.A series of organic molecules are designed and found to be effective in the treatment of COVID-19 infection.In fact,no matter how effective they are,with the development of the COVID-19 epidemic,various small molecule medicines are gradually recognized by people.This is equivalent to a good science popularization of pharmaceutical chemistry.This review aims to introduce the molecules for COVID-19 treatment on the basis of their chemical structures,synthetic methods as well as their effects.
文摘The entry of collective construction land for business purposes is an important measure for deepening the reform of the rural land system,promoting the flow of urban and rural factors,and realizing rural revitalization.Since the production of the first batch of pilot projects in 2015,33 county-level cities have participated in the pilot policy by 2023.Deqing County,Zhejiang Province,as the first area to participate in the pilot project,aims to achieve more fruitful results.This paper first examines how promoting farmers’income through the market entry of agricultural land can be achieved,then uses the synthetic control method to quantitatively study the impact of collective operational construction land on farmers’income using panel data from 2011 to 2019,and finally proposes relevant suggestions from the perspective of system reform.
基金supported by the national project"Deep Exploration Technology and Experimentation"(SinoProbe-09-02)
文摘In order to suppress the airwave noise in marine controlled-source electromagnetic （CSEM） data, we propose a 3D deconvolution （3DD） interferometry method with a synthetic aperture source and obtain the relative anomaly coefficient （RAC） of the EM field reflection responses to show the degree for suppressing the airwave. We analyze the potential of the proposed method for suppressing the airwave, and compare the proposed method with traditional methods in their effectiveness. A method to select synthetic source length is derived and the effect of the water depth on RAC is examined via numerical simulations. The results suggest that 3DD interferometry method with a synthetic source can effectively suppress the airwave and enhance the potential of marine CSEM to hydrocarbon exploration.
基金Yinyu Xiang is very grateful to the China Scholarship Council(CSC:No.201806950083)for his PhD scholarship。
文摘Lithium-sulfur(Li-S)batteries,although a promising candidate of next-generation energy storage devices,are hindered by some bottlenecks in their roadmap toward commercialization.The key challenges include solving the issues such as low utilization of active materials,poor cyclic stability,poor rate performance,and unsatisfactory Coulombic efficiency due to the inherent poor electrical and ionic conductivity of sulfur and its discharged products(e.g.,Li2S2 and Li_(2)S),dissolution and migration of polysulfide ions in the electrolyte,unstable solid electrolyte interphase and dendritic growth on an odes,and volume change in both cathodes and anodes.Owing to the high specific surface area,pore volume,low density,good chemical stability,and particularly multimodal pore sizes,hierarchical porous carbon(HPC)mate rials have received considerable attention for circumventing the above pro blems in Li-S batteries.Herein,recent progress made in the synthetic methods and deployment of HPC materials for various components including sulfur cathodes,separators and interlayers,and lithium anodes in Li-S batteries is presented and summarized.More importantly,the correlation between the structures(pore volume,specific surface area,degree of pores,and heteroatom-doping)of HPC and the electrochemical performances of Li-S batteries is elaborated.Finally,a discussion on the challenges and future perspectives associated with HPCs for Li-S batteries is provided.
基金financial support from the National Natural Science Foundation of China(22008032)the Guangdong Basic and Applied Basic Research Foundation(2019A1515110706)+1 种基金the Shandong Provincial Natural Science Foundation(ZR2020ZD08)the Guangdong Provincial Key Lab of Green Chemical Product Technology(GC202111)
文摘In recent years,an increasing amount of interest has been dedicated to the synthesis and application of ZIF-67-based materials due to their exceptionally high surface area,tunable porosity,and excellent thermal and chemical stabilities.This review summarizes the latest strategies of synthesizing ZIF-67-based materials by exploring the prominent examples.Then,the recent progress in the applications of ZIF-67-based materials in heterogeneous catalysis,including catalysis of the redox reactions,addition reactions,esterification reactions,Knoevenagel condensations,and hydrogenation-dehydrogenation reactions,has been elaborately discussed.Finally,we end this work by shedding some light on the large-scale industrial production of ZIF-67-based materials and their applications in the future.
基金supported by The Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning(No.TP2015002)the National Natural Science Foundation of China(No.51403099)
文摘Three-dimensional graphene/conducting polymer（3DGCP） composites have received significant attention in recent years due to their unique structures and promising applications in energy storage.With the structural diversity of graphene and π-functional conducting polymers via rich chemical routes,a number of 3DGCP composites with novel structures and attractive performance have been developed.Particularly,the hierarchical porosity,the interactions between graphene and conducting polymers as well as the their synergetic effects within 3DGCP composites can be well combined and elaborated by various synthetic methods,which made 3DGCP composites show unique electrochemical properties and significantly improved performance in energy storage fields compared to other graphenebased composites.In this short review,we present recent advances in 3DGCP composites in developing effective strategies to prepare 3DGCP composites and exploring them as a unique platform for supercapacitors with unprecedented performance.The challenges and future opportunities are also discussed for promotion of further study.
基金supported by the Programs of National 973 (2011CB935900)NSFC (51231003 and 21231005)+1 种基金111 Project (B12015)Tianjin High-Tech (10SYSYJC27600)
文摘The synthetic routes of porous carbons and the applications of the functional porous carbon-based composite electrode materials for lithium secondary batteries are reviewed. The synthetic methods have made great breakthroughs to control the pore size and volume, wall thickness, surface area, and connectivity of porous carbons, which result in the development of functional porous carbon-based composite electrode materials. The effects of porous carbons on the electrochemical properties are further discussed. The porous carbons as ideal matrixes to incorporate active materials make a great improvement on the electrochemical properties because of high surface area and pore volume, excellent electronic conductivity, and strong adsorption capacity. Large numbers of the composite electrode materials have been used for the devices of electrochemical energy conversion and storage, such as lithium-ion batteries （LIBs）, Li-S batteries, and Li-O2 batteries. It is believed that functional porous carbon-based composite electrode materials will continuously contribute to the field of lithium secondary batteries.
基金financially supported by the National Natural Science Foundation of China(Nos.52074227,51801186 and U1806219)the Fundamental Research Funds for the Central Universities(No.310201911cx019)。
文摘The exploration of lightweight and efficient electromagnetic wave(EMW)absorption materials is a crucial focus topic because the human body and precision instruments are exposed to the increasingly serious electromagnetic pollution.Ferrite,as the first type of EMW absorption material,is still the indelible superstar in the EMW absorption field due to its unique double loss mechanism,controllable morphology and high permeability.This review briefly introduces the EMW absorption and attenuation mechanism of ferrite-based composite absorbers,including dielectric loss dominated by charge transfer and polarization relaxation,and magnetic loss consisted of eddy current and resonance.Moreover,we comb the advances in synthesis of ferrite materials.In particular,this paper summarizes the advantages and defects of pure ferrite as EMW absorption material.And the approach to tackling the imbalance of impedance matching and highdensity in ferrite is also reviewed,including ion substitution,design of micro-morphology and doping with dielectric loss materials.
