intramolecular tandem rearrangement for the synthesis of bicyclic furans is reported.The reaction was initiated by an intramolecular cross-coupling of the built-in alkynyl sulfoxide and alkynyl sulfide motifs in the p...intramolecular tandem rearrangement for the synthesis of bicyclic furans is reported.The reaction was initiated by an intramolecular cross-coupling of the built-in alkynyl sulfoxide and alkynyl sulfide motifs in the presence of BF_(3)·Et_(2)O,followed by a[3,3]-sigmatropic sulfonium rearrangement and 5-exo-dig cyclization,affording cycloalkano[c]furans as final products in moderate yields with 100% atom economy.The synthetic utility of the resulting furans has been demonstrated through late-stage diversification by utilizing the alkylthio groups or the furan rings.展开更多
Humans and animals can be exposed to Dioxins and Furans through ingestion of fatty food, skin contact, and breathing contaminated air. Resulting health problems include skin disease, immune problems, and cancers. Mana...Humans and animals can be exposed to Dioxins and Furans through ingestion of fatty food, skin contact, and breathing contaminated air. Resulting health problems include skin disease, immune problems, and cancers. Managing the release of these chemicals is therefore important. The Stockholm Convention on Persistent Organic Pollutants requires parties to adopt measures that reduce sources of these chemicals. Sierra Leone developed its National Implementation Plan (NIP) in 2008, in compliance with this requirement. However, no known further steps have been taken, particularly at community level. In 2013, the UNDP’s GEF/SGP funded a pilot project to manage the release of Dioxins and Furans from two dumpsites in Freetown, Sierra Leone. This work was sponsored with funds from that project. The work sought to delineate the exposure of communities within and around the Bormeh-Kingtom dumpsite (Kingtom, Kolleh town, Ascension town, Crab town, and Congo town) to the chemicals. The study considered sources of exposure, relative quantities generated per year, and the routes of exposure. This exposure study is a first step in managing the release from those sources. Enumerators deployed at the dumpsite every day, 7:00 AM to 6:00 PM, for three months, quantifying and recording source materials. The amount of source materials dumped per day informed calculation of Dioxin/Furan releases in grams toxicity equivalence per year. The results revealed a release of 128.914 g TEQ/year in air and residue. This implies that the communities are at high risk of inhalation and dermal exposure. Livestock, mainly pigs, are also exposed as they feed on the waste deposited in the dumpsite. Humans in turn feed on the livestock, a recipe for biomagnification. The project team has been working on developing Best Management Practices to suppress the release of the chemicals.展开更多
Intermolecular addition-cyclization of 1, 3-dicarbonyl compounds with arylbromo- allenes in K2CO3 mediated condition afforded 2, 3, 4-trisubstituted furans in good yield.
A transition-metal-free strategy for the synthesis of tetrasubstituted furans is reported.Promoted by boron trifluo-ride diethyl etherate,the reaction of alkynyl sulfoxides with ynamides/ynol ethers proceeded via a ca...A transition-metal-free strategy for the synthesis of tetrasubstituted furans is reported.Promoted by boron trifluo-ride diethyl etherate,the reaction of alkynyl sulfoxides with ynamides/ynol ethers proceeded via a cascade process including cross-coupling of the two reactants,[3,3]-sulfonium rearrangement,and 5-exo-dig heterocyclization,leading to tetrasubstituted furan products.The resultant α-alkylthio groups can be used for further functionalization,such as to introduce other alkyl/aryl groups.展开更多
The authors have studied the Diels-Alder reactions between furan derivatives and maleimide derivatives in an ionic liquid and have found that higher reactivity can be obtained in a protic ionic liquid [Mim]Tf2N than i...The authors have studied the Diels-Alder reactions between furan derivatives and maleimide derivatives in an ionic liquid and have found that higher reactivity can be obtained in a protic ionic liquid [Mim]Tf2N than in the conventional organic solvent. Furthermore, in the Diels-Alder reactions of 2- and 2,5-alkylfurans with N-alkylma- leimide, the reactivity increases by extending the alkyl chain length of N-alkylmaleimide. In addition, it was demon- strated that endo-selectivity increases when 2,5-disubstituted furans are used. These results will be explained by comparing the stability of the Diels-Alder adduct with that of the products obtained from the reactions of 2-substituted furans and 2,5-disubstituted furans.展开更多
This paper describes the development of an integrated approach for the preparation of diverse furan derivatives from acetylenic alcohols by gold and palladium catalyzed π-activation chemistry.Notably,this new method ...This paper describes the development of an integrated approach for the preparation of diverse furan derivatives from acetylenic alcohols by gold and palladium catalyzed π-activation chemistry.Notably,this new method was found to be amenable to cyclooctyl-containing substrates,which represents a significant extension to this methodology compared with our previous reports.Furthermore,this newly developed method allowed for the direct construction of cyclooctyl furans from their synthetic precursors under Sonogashira conditions.Experimental results revealed that palladium played two major functions in these reactions,including（1） an essential catalyst in the cross-coupling reaction of the substrates;and（2）facilitating the cyclization of the acetylenic alcohol intermediates through a typical π-activation process.The scope of this chemistry was highlighted by the one-pot synthesis of 3-iodofuran,which provided an opportunity for further functionalization（via coupling methods）.Finally,the AuBr3 protocol was also elaborated to domino cyclization/C-H activation reactions,as well as the cyclization of acyclic precursors.Taken together,the results of this study demonstrate that gold and palladium catalysts can be used to complement each other in cyclization reactions.展开更多
A simple and highly efficient catalytic system for the selective aerobic oxidative ring-opening of substituted furans has been achieved using Fe(NO_(3))_(3)·9H_(2)O as a catalyst and air as an oxidant under mild ...A simple and highly efficient catalytic system for the selective aerobic oxidative ring-opening of substituted furans has been achieved using Fe(NO_(3))_(3)·9H_(2)O as a catalyst and air as an oxidant under mild conditions.A series of(Z)-1,4-enediones were obtained in good yields(up to 97%)with excellent stereoselectivity(up to>20:1 Z/E ratio).The present synthetic method exhibits perfect atom economy,wide substrate scope,and highly functionalized products allowing diverse transformations.展开更多
In pharmaceutical chemistry,five-membered aromatic heterocycles occupy a pivotal position due to their distinctive structural motifs that significantly enhance drug-like properties,including metabolic stability,solubi...In pharmaceutical chemistry,five-membered aromatic heterocycles occupy a pivotal position due to their distinctive structural motifs that significantly enhance drug-like properties,including metabolic stability,solubility,and target selectivity.These privileged structures,characterized by unique physicochemical properties and diverse biological activities,serve as fundamental building blocks for numerous clinically approved drugs.Among these heterocycles,pyrrole stands out as a privileged structural motif that is widely distributed in natural products and bioactive molecules[1,2].展开更多
Main observation and conclusion The reaction of 2-alkynylanisoles/sulfides with SOCl_(2) and DMSO was conducted to conveniently furnish the biologically interesting 3-(methylthio)-benzo[b]furans/thiophenes via intramo...Main observation and conclusion The reaction of 2-alkynylanisoles/sulfides with SOCl_(2) and DMSO was conducted to conveniently furnish the biologically interesting 3-(methylthio)-benzo[b]furans/thiophenes via intramolecular cyclization.DMSO acts as a solvent as well as a sulfur source and can also be replaced with DMSO-d_(6),enabling the incorporation of the SCD3 moiety of DMSO-d_(6) to the 3-position of the heterocyclic frameworks.展开更多
Furans bearing alkynyl substituents are highly useful in organic synthesis.However,the methodologies to access these important furan derivatives are rather limited.We herein report an efficient synthesis of alkynylate...Furans bearing alkynyl substituents are highly useful in organic synthesis.However,the methodologies to access these important furan derivatives are rather limited.We herein report an efficient synthesis of alkynylated furan derivatives based on Pd-catalyzed oxidative cross-coupling reaction between allenyl ketones and terminal alkynes.This novel synthesis of alkynylated furans with wide substrate scope is operationally simple and tolerates various functional groups.Mechanistically,the formation of the palladium carbene through cycloisomerization and the subsequent alkynyl migratory insertion are proposed as the key steps in the transformation.The reaction reported in this paper further demonstrates the generality of the carbene-based cross coupling.展开更多
The mechanisms of gold（I）-catalyzed cycloaddition of 1-（1-alkynyl） cyclopropyl ketones with nucleophiles have been investi- gated using density functional theory calculations at the B3LYP/6-31G （d, p） level of t...The mechanisms of gold（I）-catalyzed cycloaddition of 1-（1-alkynyl） cyclopropyl ketones with nucleophiles have been investi- gated using density functional theory calculations at the B3LYP/6-31G （d, p） level of theory. A polarizable continuum model （PCM） has been established in order to evaluate the effects of solvents on the reactions. The results of the calculations indicate that the first step of the catalytic cycle is the cyclization of the carbonyl oxygen onto the triple bond which forms a new and stable resonance structure of an oxonium ion and a carbocation intermediate. The subsequent ring expansion step results in the formation of the final product and regeneration of the catalyst. Furthermore, the regioselectivity and effect of substituents has been discussed, including an analysis of energy, bond length, and natural bond orbital （NBO） charge distributions in the rate-determining step. Our computational results are consistent with earlier experimental observations.展开更多
A magnetic nano-supported Cu(I)catalyst was prepared and showed high activity for cyclization of ene-yne-ketone to synthesize furans.The catalyst was easily recovered from the reaction by using external magnets and re...A magnetic nano-supported Cu(I)catalyst was prepared and showed high activity for cyclization of ene-yne-ketone to synthesize furans.The catalyst was easily recovered from the reaction by using external magnets and reused 8 times without significant loss of its catalytic activity.展开更多
The development of polymer nanoparticle composites with enhanced thermal and antibacterial properties is essential for next-generation biomedical materials.However,conventional polymers often exhibit limited bioactivi...The development of polymer nanoparticle composites with enhanced thermal and antibacterial properties is essential for next-generation biomedical materials.However,conventional polymers often exhibit limited bioactivity and poor resistance to degradation,restricting their functional applications.The novelty of this study involves the combination of the bio-derived cross-linker 2,5-bis(aminomethyl)furan(BAF)into poly(methylmethacrylate)PMMA to form a cross-linked network incorporated with various ratios of ZnO nanoparticles(ZnO NPs),resulting in improved biological and thermal properties.The surface morphologies,material crystallinity,and thermal degradation properties of the synthesized BAF-PMMA/ZnO were investigated using Scanning Electron microscopy(SEM),Energy-Dispersive X-ray spectroscopy(EDX),X-ray diffraction(XRD),andThermogravimetric characterization technique(TGA),respectively.The prepared BAF-PMMA/ZnO nanocomposites showed an enhancement in the crystallinity after increasing the ratio of ZnO NPs compared to the amorphous cross-linked BAF-PMMA polymer.The thermal stability of nanocomposites was significantly enhanced after the introduction of ZnO NPs into crosslinked BAF-PMMA polymer.The resultant nanocomposites BAF-PMMA/ZnO were examined as antibacterial agents against the Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)bacterial strains.The results showed that most BAF-PMMA/ZnO nanocomposites have antibacterial activity against both bacterial species compared to the pure cross-linked BAF-PMMA polymer.The BAF-PMMA/ZnO 10 wt.%sample shows the highest inhibition zone of(16.3±0.33)against E.coli.These outcomes demonstrate that such nanocomposites offer a viable pathway towardmultipurpose biomaterials with exceptional structural and biological features.展开更多
The structural design and performance characteristics of the diaphragm have a decisive impact on the safety and electrochemical performance of lithium-ion batteries(LIBs).However,traditional polyolefin diaphragms stil...The structural design and performance characteristics of the diaphragm have a decisive impact on the safety and electrochemical performance of lithium-ion batteries(LIBs).However,traditional polyolefin diaphragms still face challenges in simultaneously improving the ion transport efficiency and thermal stability.Here,we report an in situ dynamic lithium compensation strategy for manufacturing a biobased furan aramid/ceramic diaphragm(BAS)with higher thermal stability and ion transport efficiency.Specifically,exchangeable carboxyl groups(–COOH)are introduced into the bio-based furan aramid(BA)framework,which are in situ converted into–COOLi groups to form lithium ions(Li^(+))transport channels,achieving dynamic compensation of active Li^(+).The dual transmission system of ion exchange and physical pore channels synergistically enhances the ionic conductivity of BAS to 1.536 mS cm^(-1).The high polarity structure of the furan ring and the electrolyte have excellent compatibility,significantly reducing the solid–liquid interfacial energy,making BAS have extremely high electrolyte wettability(contact angle of 0°).The BA amide group forms a multi-scale bonding network with the nano-ceramics.The BAS prepared by the water-coating process exhibits excellent thermal stability(with a thermal shrinkage rate of less than 1%after 1 h at 150℃).The LiFePO_(4)|Li half-cell assembled with BAS shows a capacity retention rate of up to 91.7%after 280 cycles at 1C,with a Coulomb efficiency of 99%,demonstrating excellent cycling stability.This design and development based on bio-materials provides a new approach for high safety and high energy density battery systems.展开更多
Carbon dioxide(CO_(2))is the main greenhouse gas(GHG)released by human activities.The substitution of fossil resources by biomass as a bio-renewable resource,has significant potential to reduce GHG emissions.The appro...Carbon dioxide(CO_(2))is the main greenhouse gas(GHG)released by human activities.The substitution of fossil resources by biomass as a bio-renewable resource,has significant potential to reduce GHG emissions.The approach to biomass,as the only true full-scale alternative to fossil resources,is progressing rapidly.Converting biomass into furanic compounds,as versatile platform chemicals for synthesizing a wide range of bio-based products is the cornerstone of sustainable technologies.The extensive body of this review combines the biomass valorization to furanic compounds by CO_(2)utilization and furanic compounds conversion by CO_(2)fixation.These processes can be strategically applied through both‘thermochemical’and‘electrochemical’pathways,by utilizing CO_(2)from the atmosphere or industrial emission point and returning it to the natural carbon cycle.In the thermochemical pathway CO_(2)acts as a carbon source(carboxylation and polymerization)or active reaction assistant in the biomass conversion(CO_(2)-assisted conversion),without altering its oxidation state,facilitating the synthesis of valuable products and polymers.Conversely,in the electrochemical pathway,CO_(2)can be used as a carbon source(electrocarboxylation)to give the corresponding carboxylic acid,or it can undergo reduction,yielding methanol,carbon monoxide(CO),formic acid,and analogous compounds,while on the other side,furanic compounds undergo oxidation yielding high-value-added chemicals.Finally,potential future research directions are suggested to promote CO_(2)utilization and fixation in the valorization of biomass-derived furanic compounds,and challenges facing further research are highlighted.展开更多
C-H functionalization of allenes is an available strategy to construct heterocyclic compounds.Herein we propose a sus-tainable electrocatalytic C-H activation for the synthesis of novel highly functionalized tetrasubs...C-H functionalization of allenes is an available strategy to construct heterocyclic compounds.Herein we propose a sus-tainable electrocatalytic C-H activation for the synthesis of novel highly functionalized tetrasubstituted furans,which is accomplished by intermolecular cyclization of allenes and 1,3-dicarbonyl compounds.展开更多
o-Carboryne （1,2-dehydro-o-carborane） is a very useful synthon for the synthesis of a variety of carborane-functionalized molecules. Diels-Alder reaction of o-carboryne with furans gave a series of carborane-fused o...o-Carboryne （1,2-dehydro-o-carborane） is a very useful synthon for the synthesis of a variety of carborane-functionalized molecules. Diels-Alder reaction of o-carboryne with furans gave a series of carborane-fused oxanorbornenes in moderate to high yields using 1-OTf-1,2-C_2B_10H_11 as carboryne precursor. The resultant cycloadducts can undergo hydrogenation, cyclic oxidation, bromination, [4＋2]/[2＋2] cycloaddition and nucleophilic ring opening reaction to afford a variety of highly functionalized carboranes that may find applications as useful basic units in medicine and materials science.展开更多
We present here a facile and practical procedure for the synthesis of tetrasubstituted furans from alkynes catalyzed by palladium acetate together with cupric acetate in acetic acid,using atmospheric oxygen as a termi...We present here a facile and practical procedure for the synthesis of tetrasubstituted furans from alkynes catalyzed by palladium acetate together with cupric acetate in acetic acid,using atmospheric oxygen as a terminal oxidant.Various internal aromatic alkynes afforded the target furans in satisfactory yield.展开更多
Correction for‘Electrochemically-mediated C-H functionalization of allenes and 1,3-dicarbonyl compounds to construct tetrasubstituted furans’by Mu-Xue He et al.,Org.Chem.Front.,2022,DOI:10.1039/d1qo01458g.One of the...Correction for‘Electrochemically-mediated C-H functionalization of allenes and 1,3-dicarbonyl compounds to construct tetrasubstituted furans’by Mu-Xue He et al.,Org.Chem.Front.,2022,DOI:10.1039/d1qo01458g.One of the author names(Hai-Tao Tang)was spelled incorrectly in the published article;the corrected version is shown here.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.展开更多
A[3+2]cyclization reaction of acylacetonitriles and hydroxyacetone was developed by using Sc(OTf)_(3)as a catalyst to synthesize some furan derivatives.Bifunctional C2-based acetals,such asα-bromoacetaldehyde acetal,...A[3+2]cyclization reaction of acylacetonitriles and hydroxyacetone was developed by using Sc(OTf)_(3)as a catalyst to synthesize some furan derivatives.Bifunctional C2-based acetals,such asα-bromoacetaldehyde acetal,1,4-dithiane-2,5-diol and glycolaldehyde diethyl acetal,also reacted readily as alternative counterpart reagents to acylacetonitriles.The established reactions can be used to synthesize a well-known fungicide,fenfuram.Antifungal activity investigation against four common plant funguses indicated that some of the obtained furan products furnish general and high biological activities.展开更多
基金Project supported by the National Natural Science Foundation of China(No.21971042)。
文摘intramolecular tandem rearrangement for the synthesis of bicyclic furans is reported.The reaction was initiated by an intramolecular cross-coupling of the built-in alkynyl sulfoxide and alkynyl sulfide motifs in the presence of BF_(3)·Et_(2)O,followed by a[3,3]-sigmatropic sulfonium rearrangement and 5-exo-dig cyclization,affording cycloalkano[c]furans as final products in moderate yields with 100% atom economy.The synthetic utility of the resulting furans has been demonstrated through late-stage diversification by utilizing the alkylthio groups or the furan rings.
文摘Humans and animals can be exposed to Dioxins and Furans through ingestion of fatty food, skin contact, and breathing contaminated air. Resulting health problems include skin disease, immune problems, and cancers. Managing the release of these chemicals is therefore important. The Stockholm Convention on Persistent Organic Pollutants requires parties to adopt measures that reduce sources of these chemicals. Sierra Leone developed its National Implementation Plan (NIP) in 2008, in compliance with this requirement. However, no known further steps have been taken, particularly at community level. In 2013, the UNDP’s GEF/SGP funded a pilot project to manage the release of Dioxins and Furans from two dumpsites in Freetown, Sierra Leone. This work was sponsored with funds from that project. The work sought to delineate the exposure of communities within and around the Bormeh-Kingtom dumpsite (Kingtom, Kolleh town, Ascension town, Crab town, and Congo town) to the chemicals. The study considered sources of exposure, relative quantities generated per year, and the routes of exposure. This exposure study is a first step in managing the release from those sources. Enumerators deployed at the dumpsite every day, 7:00 AM to 6:00 PM, for three months, quantifying and recording source materials. The amount of source materials dumped per day informed calculation of Dioxin/Furan releases in grams toxicity equivalence per year. The results revealed a release of 128.914 g TEQ/year in air and residue. This implies that the communities are at high risk of inhalation and dermal exposure. Livestock, mainly pigs, are also exposed as they feed on the waste deposited in the dumpsite. Humans in turn feed on the livestock, a recipe for biomagnification. The project team has been working on developing Best Management Practices to suppress the release of the chemicals.
基金We are grateful to the National Natural Science Foundation of China(No.20472072,20332060).
文摘Intermolecular addition-cyclization of 1, 3-dicarbonyl compounds with arylbromo- allenes in K2CO3 mediated condition afforded 2, 3, 4-trisubstituted furans in good yield.
文摘A transition-metal-free strategy for the synthesis of tetrasubstituted furans is reported.Promoted by boron trifluo-ride diethyl etherate,the reaction of alkynyl sulfoxides with ynamides/ynol ethers proceeded via a cascade process including cross-coupling of the two reactants,[3,3]-sulfonium rearrangement,and 5-exo-dig heterocyclization,leading to tetrasubstituted furan products.The resultant α-alkylthio groups can be used for further functionalization,such as to introduce other alkyl/aryl groups.
文摘The authors have studied the Diels-Alder reactions between furan derivatives and maleimide derivatives in an ionic liquid and have found that higher reactivity can be obtained in a protic ionic liquid [Mim]Tf2N than in the conventional organic solvent. Furthermore, in the Diels-Alder reactions of 2- and 2,5-alkylfurans with N-alkylma- leimide, the reactivity increases by extending the alkyl chain length of N-alkylmaleimide. In addition, it was demon- strated that endo-selectivity increases when 2,5-disubstituted furans are used. These results will be explained by comparing the stability of the Diels-Alder adduct with that of the products obtained from the reactions of 2-substituted furans and 2,5-disubstituted furans.
基金supported by the Department of Science and Technology(INSPIRE Faculty Program),India~~
文摘This paper describes the development of an integrated approach for the preparation of diverse furan derivatives from acetylenic alcohols by gold and palladium catalyzed π-activation chemistry.Notably,this new method was found to be amenable to cyclooctyl-containing substrates,which represents a significant extension to this methodology compared with our previous reports.Furthermore,this newly developed method allowed for the direct construction of cyclooctyl furans from their synthetic precursors under Sonogashira conditions.Experimental results revealed that palladium played two major functions in these reactions,including（1） an essential catalyst in the cross-coupling reaction of the substrates;and（2）facilitating the cyclization of the acetylenic alcohol intermediates through a typical π-activation process.The scope of this chemistry was highlighted by the one-pot synthesis of 3-iodofuran,which provided an opportunity for further functionalization（via coupling methods）.Finally,the AuBr3 protocol was also elaborated to domino cyclization/C-H activation reactions,as well as the cyclization of acyclic precursors.Taken together,the results of this study demonstrate that gold and palladium catalysts can be used to complement each other in cyclization reactions.
基金supported by the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(No.2022R01007)a Start-up Research Grant from Zhejiang Normal University,the National Key Research and Development Program of China(No.2021YFA0804900)+1 种基金the NSFC(No.21971062)Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism.
文摘A simple and highly efficient catalytic system for the selective aerobic oxidative ring-opening of substituted furans has been achieved using Fe(NO_(3))_(3)·9H_(2)O as a catalyst and air as an oxidant under mild conditions.A series of(Z)-1,4-enediones were obtained in good yields(up to 97%)with excellent stereoselectivity(up to>20:1 Z/E ratio).The present synthetic method exhibits perfect atom economy,wide substrate scope,and highly functionalized products allowing diverse transformations.
基金supported by the National Key R&D Program of China(2023YFA1507203 and 2024YFA1509700)the National Natural Science Foundation of China(92256301,22271113,and 22471089).
文摘In pharmaceutical chemistry,five-membered aromatic heterocycles occupy a pivotal position due to their distinctive structural motifs that significantly enhance drug-like properties,including metabolic stability,solubility,and target selectivity.These privileged structures,characterized by unique physicochemical properties and diverse biological activities,serve as fundamental building blocks for numerous clinically approved drugs.Among these heterocycles,pyrrole stands out as a privileged structural motif that is widely distributed in natural products and bioactive molecules[1,2].
基金We acknowledge the National Natural Science Foundation of China(No.21472136)for financial support.
文摘Main observation and conclusion The reaction of 2-alkynylanisoles/sulfides with SOCl_(2) and DMSO was conducted to conveniently furnish the biologically interesting 3-(methylthio)-benzo[b]furans/thiophenes via intramolecular cyclization.DMSO acts as a solvent as well as a sulfur source and can also be replaced with DMSO-d_(6),enabling the incorporation of the SCD3 moiety of DMSO-d_(6) to the 3-position of the heterocyclic frameworks.
基金supported by NSFC(22371008),BNLMSLaboratory for Synthetic Chemistry and Chemical Biology of Health@InnoHK of ITC,HKSAR.
文摘Furans bearing alkynyl substituents are highly useful in organic synthesis.However,the methodologies to access these important furan derivatives are rather limited.We herein report an efficient synthesis of alkynylated furan derivatives based on Pd-catalyzed oxidative cross-coupling reaction between allenyl ketones and terminal alkynes.This novel synthesis of alkynylated furans with wide substrate scope is operationally simple and tolerates various functional groups.Mechanistically,the formation of the palladium carbene through cycloisomerization and the subsequent alkynyl migratory insertion are proposed as the key steps in the transformation.The reaction reported in this paper further demonstrates the generality of the carbene-based cross coupling.
基金supported by the Natural Science Foundation of Gansu Province (10710RJZA114)
文摘The mechanisms of gold（I）-catalyzed cycloaddition of 1-（1-alkynyl） cyclopropyl ketones with nucleophiles have been investi- gated using density functional theory calculations at the B3LYP/6-31G （d, p） level of theory. A polarizable continuum model （PCM） has been established in order to evaluate the effects of solvents on the reactions. The results of the calculations indicate that the first step of the catalytic cycle is the cyclization of the carbonyl oxygen onto the triple bond which forms a new and stable resonance structure of an oxonium ion and a carbocation intermediate. The subsequent ring expansion step results in the formation of the final product and regeneration of the catalyst. Furthermore, the regioselectivity and effect of substituents has been discussed, including an analysis of energy, bond length, and natural bond orbital （NBO） charge distributions in the rate-determining step. Our computational results are consistent with earlier experimental observations.
基金supported by the Natural Science Foundation of Guangdong Province(No.10151022501000033).
文摘A magnetic nano-supported Cu(I)catalyst was prepared and showed high activity for cyclization of ene-yne-ketone to synthesize furans.The catalyst was easily recovered from the reaction by using external magnets and reused 8 times without significant loss of its catalytic activity.
文摘The development of polymer nanoparticle composites with enhanced thermal and antibacterial properties is essential for next-generation biomedical materials.However,conventional polymers often exhibit limited bioactivity and poor resistance to degradation,restricting their functional applications.The novelty of this study involves the combination of the bio-derived cross-linker 2,5-bis(aminomethyl)furan(BAF)into poly(methylmethacrylate)PMMA to form a cross-linked network incorporated with various ratios of ZnO nanoparticles(ZnO NPs),resulting in improved biological and thermal properties.The surface morphologies,material crystallinity,and thermal degradation properties of the synthesized BAF-PMMA/ZnO were investigated using Scanning Electron microscopy(SEM),Energy-Dispersive X-ray spectroscopy(EDX),X-ray diffraction(XRD),andThermogravimetric characterization technique(TGA),respectively.The prepared BAF-PMMA/ZnO nanocomposites showed an enhancement in the crystallinity after increasing the ratio of ZnO NPs compared to the amorphous cross-linked BAF-PMMA polymer.The thermal stability of nanocomposites was significantly enhanced after the introduction of ZnO NPs into crosslinked BAF-PMMA polymer.The resultant nanocomposites BAF-PMMA/ZnO were examined as antibacterial agents against the Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)bacterial strains.The results showed that most BAF-PMMA/ZnO nanocomposites have antibacterial activity against both bacterial species compared to the pure cross-linked BAF-PMMA polymer.The BAF-PMMA/ZnO 10 wt.%sample shows the highest inhibition zone of(16.3±0.33)against E.coli.These outcomes demonstrate that such nanocomposites offer a viable pathway towardmultipurpose biomaterials with exceptional structural and biological features.
基金the financial support from the National Natural Science Foundation of China(22293011,T2341001)the Major Science and Technology Project of Anhui Province(202203a06020010)+1 种基金the Horizontal Project Provided by Jiangsu Zhuogao New Materials Technology Co.,Ltd.(Td00923003H)Joint Laboratory by China Power Investment Ronghe New Energy Technology Co.,Ltd.and the Central Government Guiding Special Fund Project for Local Science and Technology Development(202407a12020008)。
文摘The structural design and performance characteristics of the diaphragm have a decisive impact on the safety and electrochemical performance of lithium-ion batteries(LIBs).However,traditional polyolefin diaphragms still face challenges in simultaneously improving the ion transport efficiency and thermal stability.Here,we report an in situ dynamic lithium compensation strategy for manufacturing a biobased furan aramid/ceramic diaphragm(BAS)with higher thermal stability and ion transport efficiency.Specifically,exchangeable carboxyl groups(–COOH)are introduced into the bio-based furan aramid(BA)framework,which are in situ converted into–COOLi groups to form lithium ions(Li^(+))transport channels,achieving dynamic compensation of active Li^(+).The dual transmission system of ion exchange and physical pore channels synergistically enhances the ionic conductivity of BAS to 1.536 mS cm^(-1).The high polarity structure of the furan ring and the electrolyte have excellent compatibility,significantly reducing the solid–liquid interfacial energy,making BAS have extremely high electrolyte wettability(contact angle of 0°).The BA amide group forms a multi-scale bonding network with the nano-ceramics.The BAS prepared by the water-coating process exhibits excellent thermal stability(with a thermal shrinkage rate of less than 1%after 1 h at 150℃).The LiFePO_(4)|Li half-cell assembled with BAS shows a capacity retention rate of up to 91.7%after 280 cycles at 1C,with a Coulomb efficiency of 99%,demonstrating excellent cycling stability.This design and development based on bio-materials provides a new approach for high safety and high energy density battery systems.
基金the National Key R&D Program of China(No.2021YFC2101604)National Natural Science Foundation of China(Nos.U23A20123,22278339)+1 种基金Fujian Provincial Key Science and Technology Program of China(No.2022YZ037013)Xiamen University for the financial support.
文摘Carbon dioxide(CO_(2))is the main greenhouse gas(GHG)released by human activities.The substitution of fossil resources by biomass as a bio-renewable resource,has significant potential to reduce GHG emissions.The approach to biomass,as the only true full-scale alternative to fossil resources,is progressing rapidly.Converting biomass into furanic compounds,as versatile platform chemicals for synthesizing a wide range of bio-based products is the cornerstone of sustainable technologies.The extensive body of this review combines the biomass valorization to furanic compounds by CO_(2)utilization and furanic compounds conversion by CO_(2)fixation.These processes can be strategically applied through both‘thermochemical’and‘electrochemical’pathways,by utilizing CO_(2)from the atmosphere or industrial emission point and returning it to the natural carbon cycle.In the thermochemical pathway CO_(2)acts as a carbon source(carboxylation and polymerization)or active reaction assistant in the biomass conversion(CO_(2)-assisted conversion),without altering its oxidation state,facilitating the synthesis of valuable products and polymers.Conversely,in the electrochemical pathway,CO_(2)can be used as a carbon source(electrocarboxylation)to give the corresponding carboxylic acid,or it can undergo reduction,yielding methanol,carbon monoxide(CO),formic acid,and analogous compounds,while on the other side,furanic compounds undergo oxidation yielding high-value-added chemicals.Finally,potential future research directions are suggested to promote CO_(2)utilization and fixation in the valorization of biomass-derived furanic compounds,and challenges facing further research are highlighted.
基金This work was supported by National Natural Science Foundation of China(22161008,21861006,22061003)Guangxi Natural Science Foundation of China(2021GXNSFFA220005)the Chunhui Program(GX2019001).
文摘C-H functionalization of allenes is an available strategy to construct heterocyclic compounds.Herein we propose a sus-tainable electrocatalytic C-H activation for the synthesis of novel highly functionalized tetrasubstituted furans,which is accomplished by intermolecular cyclization of allenes and 1,3-dicarbonyl compounds.
文摘o-Carboryne （1,2-dehydro-o-carborane） is a very useful synthon for the synthesis of a variety of carborane-functionalized molecules. Diels-Alder reaction of o-carboryne with furans gave a series of carborane-fused oxanorbornenes in moderate to high yields using 1-OTf-1,2-C_2B_10H_11 as carboryne precursor. The resultant cycloadducts can undergo hydrogenation, cyclic oxidation, bromination, [4＋2]/[2＋2] cycloaddition and nucleophilic ring opening reaction to afford a variety of highly functionalized carboranes that may find applications as useful basic units in medicine and materials science.
基金We thank Scientific and Technological Project of Zhanjiang City(No.2012C3106024)Guangdong Medical College(No.M2010006)for financial support.
文摘We present here a facile and practical procedure for the synthesis of tetrasubstituted furans from alkynes catalyzed by palladium acetate together with cupric acetate in acetic acid,using atmospheric oxygen as a terminal oxidant.Various internal aromatic alkynes afforded the target furans in satisfactory yield.
文摘Correction for‘Electrochemically-mediated C-H functionalization of allenes and 1,3-dicarbonyl compounds to construct tetrasubstituted furans’by Mu-Xue He et al.,Org.Chem.Front.,2022,DOI:10.1039/d1qo01458g.One of the author names(Hai-Tao Tang)was spelled incorrectly in the published article;the corrected version is shown here.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.
基金The authors thank the financial support of the Natural Science Foundation of Hubei Province(No.2020CFB717)the Youth Science Foundation of Hubei Academy of Agricultural Sciences(No.2021NKYJJ17)+2 种基金also gratefully acknowledge the partial support from the Program for Leading Talents of Hubei Academy of Agricultural Sciences(No.L2018031)Hubei Biopesticide Engineering Research Centre(Nos.HBERC-RC-202104 and HBERC-RC-202002)Gu thanks the National Natural Science Foundation of China of China(No.22072049).
文摘A[3+2]cyclization reaction of acylacetonitriles and hydroxyacetone was developed by using Sc(OTf)_(3)as a catalyst to synthesize some furan derivatives.Bifunctional C2-based acetals,such asα-bromoacetaldehyde acetal,1,4-dithiane-2,5-diol and glycolaldehyde diethyl acetal,also reacted readily as alternative counterpart reagents to acylacetonitriles.The established reactions can be used to synthesize a well-known fungicide,fenfuram.Antifungal activity investigation against four common plant funguses indicated that some of the obtained furan products furnish general and high biological activities.
