A sulfonium ylide participated alkylation and arylation under transition-metal free conditions is described.The disparate reaction pattern allowed the separate activation of non-ylidic S-alkyl and S-aryl bond.Under ac...A sulfonium ylide participated alkylation and arylation under transition-metal free conditions is described.The disparate reaction pattern allowed the separate activation of non-ylidic S-alkyl and S-aryl bond.Under acidic conditions,sulfonium ylides serve as alkyl cation precursors which facilitate the alkylations.While under alkaline conditions,cleavage of non-ylidic S-aryl bond produces O-arylated compounds efficiently.The robustness of the protocols were established by the excellent compatibility of wide variety of substrates including carbohydrates.展开更多
A concise approach to the synthesis of organoiron intermediate from organoboron and Fe(III)has been developed,and the reactivity of the intermediate with a series of electrophiles has been investigated.The results rev...A concise approach to the synthesis of organoiron intermediate from organoboron and Fe(III)has been developed,and the reactivity of the intermediate with a series of electrophiles has been investigated.The results revealed that pinacol substituent of organoboron is crucial for C—B cleavage.The resulted organoiron intermediate is not stable,with weak nucleophicility.The coupling reactions of organoiron intermediate with acyl chlorides,anhydrides,isocyanates have been performed.展开更多
The lack of macro-continuity and mechanical strength of covalent organic frameworks(COFs)has significantly limited their practical applications.Here,we propose an“alcohol-triggered defect cleavage”strategy to precis...The lack of macro-continuity and mechanical strength of covalent organic frameworks(COFs)has significantly limited their practical applications.Here,we propose an“alcohol-triggered defect cleavage”strategy to precisely regulate the growth and stacking of COF grains through a moderate reversed Schiff base reaction,realizing the direct synthesis of COF nanofibers(CNFs)with high aspect ratio(L/D=103.05)and long length(>20μm).An individual CNF exhibits a biomimetic scale-like architecture,achieving superior flexibility and fatigue resistance under dynamic bending via a multiscale stress dissipation mechanism.Taking advantages of these structural features,we engineer CNF aerogels(CNF-As)with programmable porous structures(e.g.,honeycomb,lamellar,isotropic)via directional ice-template methodology.CNF-As demonstrate 100%COF content,high specific surface area(396.15 m^(2)g^(-1))and superelasticity(~0%elastic deformation after 500 compression cycles at 50%strain),outperforming most COF-based counterparts.Compared with the conventional COF aerogels,the unique structural features of CNF-A enable it to perform outstandingly in uranium extraction,with an 11.72-fold increment in adsorption capacity(920.12 mg g^(-1))and adsorption rate(89.9%),and a 2.48-fold improvement in selectivity(U/V=2.31).This study provides a direct strategy for the development of next-generation COF materials with outstanding functionality and structural robustness.展开更多
Based upon computer-assisted predictions on the secondary structures of tobacco mosaicvirus (TMV) genomic RNA (both polarities), hammerhead type ribozymes were synthesizedin vitro, which all shared a conserved domain ...Based upon computer-assisted predictions on the secondary structures of tobacco mosaicvirus (TMV) genomic RNA (both polarities), hammerhead type ribozymes were synthesizedin vitro, which all shared a conserved domain adapted from satellite tobacco ringspot virus(sTobRV)RNA. Ribozymes RZ1, RZ2 and RZ3 were designed to cleave the phosphodiester bondsimmediate to the 3'--end of GUC between the residues 5384-5385 and 6312--6313 on the plusstrand and 1214-1215 on the minus strand, respectively. The in vitro data indicated that RZ1 wasable to cleave completely its substrates BT1(+ ) and BT2(+ ), representing partial sequencesof the plus strand of the TMV MP region at 50, 37 and 30℃ with a molar ratio of ribozymeto the target as low as 1:1. Its two iso-ribozymes RZ1A and RZ1B which were respectivelymodified to contain a CUUCGG sequence in the conserved region and in an additional 3'-ter-minal stem-loop of UUUUUCUUCGGAAAAA were able to cleave BT1(+) and BT2(+) asefficiently as RZ1. Ribozyme RZ3 cleaved, with less efficiency, its substrate BT2(-), repre-senting the minus strand of the TMV MP gene at 50, 37 or 30℃ even with a molar ratio ofribozyme to the target as high as 4:1. Ribozyme RZ2, however, had not any visible activityto its substrate BT3(+ ), representing the sequence was involved in the 3'--terminal tRNA--likesequence even though it was incubated for 5 min at 65℃ before being exposed to the ribozyme.展开更多
Mutations in the Contactin-associated protein-like 2(CNTNAP2)gene are associated with autism spectrum disorder(ASD),and ectodomain shedding of the CNTNAP2 protein plays a role in its function.However,key enzymes invol...Mutations in the Contactin-associated protein-like 2(CNTNAP2)gene are associated with autism spectrum disorder(ASD),and ectodomain shedding of the CNTNAP2 protein plays a role in its function.However,key enzymes involved in the C-terminal cleavage of CNTNAP2 remain largely unknown,and the effect of ASD-associated mutations on this process and its role in ASD pathogenesis remain elusive.In this report we showed that CNTNAP2 undergoes sequential cleavages by furin,ADAM10/17-dependent a-secretase and presenilindependent y-secretase.We identified that the cleavage sites of ADAM10 and ADAM17 in CNTNAP2 locate at its C-terminal residue I79 and L96,and the main a-cleavage product C79 by ADAM10 is required for the subsequent y-secretase cleavage to generate CNTNAP2 intracellular domain(CICD).ASD-associated CNTNAP2 mutations impair the a-cleavage to generate C79,and the inhibition leads to ASDIlike repetitive and social behavior abnormalties in the Cntnap2l1254T knock-in mice.Finaly,exogenous expression of 79 improves autism-ike phenotypes in the Cntnap2^(11254T) knock-in and Cntnap2^(-/-)knockout mice.This data demonstrates that the a-secretase is essential for CNTNAP2 processing and its function.Our study indicates that inhibition of the cleavage by pathogenic mutations underlies ASD pathogenesis,and upregulation of its C-terminal fragments could have therapeutical potentials for ASD treatment.展开更多
In the realm of drug discovery,recent advancements have paved the way for innovative approaches and methodologies.This comprehensive review encapsulates six distinct yet interrelated mini-reviews,each shedding light o...In the realm of drug discovery,recent advancements have paved the way for innovative approaches and methodologies.This comprehensive review encapsulates six distinct yet interrelated mini-reviews,each shedding light on novel strategies in drug development.(a)The resurgence of covalent drugs is highlighted,focusing on the targeted covalent inhibitors(TCIs)and their role in enhancing selectivity and affinity.(b)The potential of the quantum mechanics-based computational aid drug design(CADD)tool,Cov_DOX,is introduced for predicting protein-covalent ligand binding structures and affinities.(c)The scaffolding function of proteins is proposed as a new avenue for drug design,with a focus on modulating protein-protein interactions through small molecules and proteolysis targeting chimeras(PROTACs).(d)The concept of pro-PROTACs is explored as a promising strategy for cancer therapy,combining the principles of prodrugs and PROTACs to enhance specificity and reduce toxicity.(e)The design of prodrugs through carbon-carbon bond cleavage is discussed,offering a new perspective for the activation of drugs with limited modifiable functional groups.(f)The targeting of programmed cell death pathways in cancer therapies with small molecules is reviewed,emphasizing the induction of autophagy-dependent cell death,ferroptosis,and cuproptosis.These insights collectively contribute to a deeper understanding of the dynamic landscape of drug discovery.展开更多
Direct ethanol fuel cells(DEFCs)are a promising alternative to conventional energy sources,offering high energy density,environmental sustainability,and operational safety.Compared to methanol fuel cells,DEFCs exhibit...Direct ethanol fuel cells(DEFCs)are a promising alternative to conventional energy sources,offering high energy density,environmental sustainability,and operational safety.Compared to methanol fuel cells,DEFCs exhibit lower toxicity and a more mature preparation process.Unlike hydrogen fuel cells,DEFCs provide superior storage and transport feasibility,as well as cost-effectiveness,significantly enhancing their commercial viability.However,the stable C-C bond in ethanol creates a high activation energy barrier,often resulting in incomplete electrooxidation.Current commercial platinum(Pt)-and palladium(Pd)-based catalysts demonstrate low C-C bond cleavage efficiency(<7.5%),severely limiting DEFC energy output and power density.Furthermore,high catalyst costs and insufficient activity impede large-scale commercialization.Recent advances in DEFC anode catalyst design have focused on optimizing material composition and elucidating catalytic mechanisms.This review systematically examines developments in ethanol electrooxidation catalysts over the past five years,highlighting strategies to improve C1 pathway selectivity and C-C bond activation.Key approaches,such as alloying,nanostructure engineering,and interfacial synergy effects,are discussed alongside their mechanistic implications.Finally,we outline current challenges and future prospects for DEFC commercialization.展开更多
The valorization of biomass to produce biofuels has become a heavily investigated field due to the depletion of fossil fuels and environmental concerns.Among them,the research on deoxygenation of fatty acids or esters...The valorization of biomass to produce biofuels has become a heavily investigated field due to the depletion of fossil fuels and environmental concerns.Among them,the research on deoxygenation of fatty acids or esters derived from biomass as well as municipal sludge organics to produce diesel-like hydrocarbons has become a hot topic.Fatty acid is a key intermediate derived from ester hydrolysis,therefore has attracted more attention as a model compound.In this review,we first introduce and compare the three reaction pathways of hydrodeoxygenation,decarboxylation and decarbonylation,for the deoxygenation of fatty acids and esters.The preference of reaction pathway is closely related to the type of raw materials and catalysts as well as reaction conditions.The special purpose of this review is to summarize the dilemma and possible strategies for deoxygenation of fatty acids,which is expected to provide guidance for future exploration and concentrates.The atom utilization along with stability during reaction in a long time is the most important index for commercial economy.Herein,we propose that the rational design and delicate synthesis of stable single-atom non-noble catalysts may be the best solution.The ultimately goal is aiming to develop sustainable production of green diesel hydrocarbons.展开更多
Novel benzo-bridged hexaphyrin(2.1.2.1.2.1)and its copper complex were synthesized.Single-crystal structures showed typical figure-of-eight Huckel topologies.NMR,NICS,HOMA,ACID,and EDDB analysis supported their non-ar...Novel benzo-bridged hexaphyrin(2.1.2.1.2.1)and its copper complex were synthesized.Single-crystal structures showed typical figure-of-eight Huckel topologies.NMR,NICS,HOMA,ACID,and EDDB analysis supported their non-aromatic properties owning to the strong local aromatic benzo rings cutting the global aromatic ring of the benzo-bridged figure-of-eight hexaphyrin(2.1.2.1.2.1).The redox properties and degenerate HOMOs and LUMOs levels indicate multielectron donating and accepting abilities.展开更多
Ultrasound(US),as an efficient and non-invasive trigger,has been extensively explored in drug delivery and has many advantages,such as deep penetration,low invasiveness,and high biochemical precision.These advantages ...Ultrasound(US),as an efficient and non-invasive trigger,has been extensively explored in drug delivery and has many advantages,such as deep penetration,low invasiveness,and high biochemical precision.These advantages demonstrate the immense clinical potential of ultrasound.This study aimed to provide a comprehensive analysis of ultrasound-induced shear forces that exhibit covalent/non-covalent bond cleavage and reactive oxygen species(ROS)-mediated remote control of nanocarriers.By doing so,we can gain a deeper understanding of the vital role,significant advantages,and untapped potential of ultrasound in molecular-level drug activation.Furthermore,clinical translation faces challenges such as the low drug-loading capacity of polymer chains,frequency compatibility between ultrasound parameters and biological systems,insufficient ROS generation,and biocompatibility of current sonosensitizers.To solve these problems,ultrasound mechanochemistry has emerged as a versatile therapeutic modality to promote the development of medical treatments.展开更多
The oxidation of lignin model compounds to esters via C-C bond cleavage has attracted considerable attention,as esters could be used as important polymer precursors and pharmaceutical intermediates.However,most studie...The oxidation of lignin model compounds to esters via C-C bond cleavage has attracted considerable attention,as esters could be used as important polymer precursors and pharmaceutical intermediates.However,most studies focus on designing homogeneous or noble metal catalysts and conducting the reactions under basic conditions.Here,we report an efficient process for the C-C bond cleavage of lignin model compounds and selectively producing esters over different shaped CeO_(2)(i.e.,nanospheres(S),nanorods(R),nanoparticles(P),and nanocubes(C))under base-free conditions.Specifically,the yield of methyl anisate from the aerobic oxidation of l-(4-methoxyphenyl)ethanol reaches 77.6%over CeO_(2)-S in one hour(91%in 9 h),exhibiting higher performance compared to other evaluated CeO_(2)catalysts(6.4%-40.2%).Extensivecharacterizations and experimental investigations reveal that the density of weak base sites and oxygen vacancies on the CeO_(2)surface is positively correlated with the yield of methyl esters.Furthermore,the reaction pathway is investigated,which confirms that 1-(4-methoxyphenyl)ethanol first undergoes two reactions(i.e.,etherification and dehydrogenation)to produce intermediates of1-methoxy-4-(1-methoxy-ethyl)-benzene and 1-(4-methoxyphenyl)ethanone,respectively,followed by a series of functional group transformations to generate the targeted methyl anisate ultimately.展开更多
Pyridyl-based ketones and 1,6-diketones are both attractive and invaluable scaffolds which play pivotal roles in the construction and structural modification of a plethora of synthetically paramount natural products,p...Pyridyl-based ketones and 1,6-diketones are both attractive and invaluable scaffolds which play pivotal roles in the construction and structural modification of a plethora of synthetically paramount natural products,pharmaceuticals,organic materials and fine chemicals.In this context,we herein demonstrate an unprecedented,robust and generally applicable synthetically strategy to deliver these two crucial ketone frameworks via visible-light-induced ring-opening coupling reactions of cycloalcohols with vinylazaarenes and enones,respectively.A plausible mechanism involves the selectiveβ-C-C bond cleavage of cycloalcohols enabled by proton-coupled electron transfer and ensuing Giese-type addition followed by single electron reduction and protonation.The synthetic methodology exhibits broad substrate scope,excellent functional group compatibility as well as operational simplicity and environmental friendliness.展开更多
The efficient conversion of lignin into mono-cycloalkanes via both C–O and C–C bonds cleavage are attractive,but challenging due to the high C–C bond dissociation energy.Previous studies have demonstrated that NbO_...The efficient conversion of lignin into mono-cycloalkanes via both C–O and C–C bonds cleavage are attractive,but challenging due to the high C–C bond dissociation energy.Previous studies have demonstrated that NbO_(x)-based catalysts exhibited exceptional capabilities for C_(Ar)–C bond cleavage and broken the limitation of lignin monomers.In this work,we presented an economical multifunctional Pt-Nb/MOR catalyst that achieved an impressive monomer yield of 147%during the depolymerization and hydrodeoxygenation of lignin into mono-cycloalkanes.Reaction pathway studies showed that unlike traditional NbO_(x)-based catalytic system,bicyclohexane was an important intermediate in this system and followed the C_(sp3)–C_(sp3)cleavage pathway after complete cyclic-hydrogenation.Deep investigations demonstrated that the doping of Nb in Pt/MOR not only enhanced the activation of hydrogen by Pt,but also increased the acidity of MOR,both of these are favor for the hydrogenolytic cleavage of C_(sp3)–C_(sp3)bonds.This work provides a low-cost catalyst to obtain high-yield monomers from lignin under relatively mild conditions and would help to design catalysts with higher activity for the valorization of lignin.展开更多
Lignin is the only largest renewable aromatic resource in nature.Currently,most lignin is underutilized for low-value applications due to the complex structure and recalcitrant chemical properties.Over the past decade...Lignin is the only largest renewable aromatic resource in nature.Currently,most lignin is underutilized for low-value applications due to the complex structure and recalcitrant chemical properties.Over the past decades,extensive research has been devoted to valorizing lignin into aromatic N-heterocycles in the presence of nitrogen sources.It overcomes the element limitation,expands the products portfolio and would play a momentous role in value-added biorefinery concept.In this review,the latest research progress in the synthesis of N-heterocyclic compounds from lignin,lignin model compounds,and lignin-derived monomers(phenols,aromatic alcohols,aldehydes,ketones,and ethers)is presented.According to the structural characteristics of the products,these achievements are classified by the construction of five-,six-,and seven-membered N-heterocyclic compounds through one-step,multi-step,or one-pot multi-step reactions.Furthermore,the tailor-designed routes and catalytic systems,along with the reaction mechanisms/pathways involved are entirely discussed to elucidate the challenges regarding the structural complexity of lignin,the incompatible catalysis for C–O cleavage and C–N formation,as well as the nitrogen-heterocyclic ring construction.The prospects,future research efforts and process developments for the refining of lignin into aromatic N-heterocyclic compounds are outlined in terms of economy,environmental friendliness,and safety so as to draw some guidelines for lignin valorization.展开更多
Designing Fischer-Tropsch synthesis(FTS)catalysts to selectively produce liquid hydrocarbon fuels is a crucial challenge.Herein,we selectively introduced Co nanoparticles(NPs)into the micropores and mesopores of an or...Designing Fischer-Tropsch synthesis(FTS)catalysts to selectively produce liquid hydrocarbon fuels is a crucial challenge.Herein,we selectively introduced Co nanoparticles(NPs)into the micropores and mesopores of an ordered mesoporous MFI zeolite(OMMZ)through impregnation,which controlled the carbon number distribution in the FTS products by tuning the position of catalytic active sites in differently sized pores.The Co precursors coordinated by acetate with a size of 9.4×4.2×2.5Åand by 2,2'-bipyridine with a size of 9.5×8.7×7.9Å,smaller and larger than the micropores(ca.5.5Å)of MFI,made the Co species incorporated in OMMZ's micropores and mesopores,respectively.The carbon number products synthesized with the Co NPs confined in mesopores were larger than that in micropores.The high jet and diesel selectivities of 66.5%and 65.3%were achieved with Co NPs confined in micropores and mesopores of less acidic Na-type OMMZ,respectively.Gasoline and jet selectivities of 76.7%and 70.8%were achieved with Co NPs confined in micropores and mesopores of H-type OMMZ with Brönsted acid sites,respectively.A series of characterizations revealed that the selective production of diesel and jet fuels was due to the C-C cleavage suppressing of heavier hydrocarbons by the Co NPs located in mesopores.展开更多
While variable regions of immunoglobulins are extensively diversified by V(D)J recombination and somatic hypermutation in vertebrates,the constant regions of immunoglobulin heavy chains also utilize certain mechanisms...While variable regions of immunoglobulins are extensively diversified by V(D)J recombination and somatic hypermutation in vertebrates,the constant regions of immunoglobulin heavy chains also utilize certain mechanisms to produce diversity,including class switch recombination(CSR),subclass differentiation,and alternative expression of the same gene.Many species of birds,reptiles,and amphibians express a truncated isoform of immunoglobulin Y(IgY),termed IgY(ΔFc),which lacks theυCH3 andυCH4 domains.In Anseriformes,IgY(ΔFc)arises from alternative transcriptional termination sites within the sameυgene,whereas in some turtles,intact IgY and IgY(ΔFc)are encoded by distinct genes.Different from the previously reported IgY(ΔFc)variants,this study identified a truncated IgY in the snake Elaphe taeniura,characterized by the loss of only a portion of the CH4 domain.Western blotting and liquid chromatographytandem mass spectrometry confirmed that this truncated IgY is generated by post-translational cleavage at N338 within the IgY heavy chain constant(CH)region.Furthermore,both human and snake asparaginyl endopeptidase were shown to cleave snake IgY in vitro.These findings reveal a novel mechanism for the production of shortened IgY forms,demonstrating that the immunoglobulin CH region undergoes diversification through distinct strategies across vertebrates.展开更多
Heterogeneous precious metal catalysts are prone to agglomeration during preparation,requiring high usage with consequently high costs.Maximizing the efficiency of precious-metal utilization is of great significance i...Heterogeneous precious metal catalysts are prone to agglomeration during preparation,requiring high usage with consequently high costs.Maximizing the efficiency of precious-metal utilization is of great significance in the design of supported precious metal catalysts.Herein,2,2'-bipyridyl-5,5'-dicarboxylic acid was used as the ligand in constructing the UiO-67-Ce-BPyDC framework with Ce^(4+)coordination.This framework enables precise adsorption and coordination of Pd2+at the nitrogen sites of pyridine,promoting high dispersion of the Pd species at a single site,thereby facilitating controlled palladium loading.This precursor was used to fabricate supported Pd-based catalysts on CeO_(2)(Pd-N/CeO_(2)-P)via pyrolysis.Notably,because the Pd species are homogeneously distributed on CeO_(2)with strong interactions,Pd-N/CeO_(2)-P exhibits remarkable efficiency in cleaving the C-O bonds of diphenyl ether(DPE)to produce cyclohexanol,with a selectivity of 72.1%.The origin of the high selectivity of cyclohexanol is further elucidated using theoretical calculations;that is,DPE undergoes not only hydrogenolysis on Pd-N/CeO_(2)-P,but also hydrolysis to produce more cyclohexanol.This study not only demonstrates a successful strategy for designing highly dispersed metal catalysts,but also underscores the importance of such tailored catalysts in the advancement of sustainable lignin depolymerization technologies.展开更多
Catalytic aryl ether C—O bonds hydrogenolysis was an important route to convert lignite into high valueadded chemicals.Solid super acid 10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) catalysts were successfully synthesized and evalua...Catalytic aryl ether C—O bonds hydrogenolysis was an important route to convert lignite into high valueadded chemicals.Solid super acid 10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) catalysts were successfully synthesized and evaluated their performance in catalytic hydrolysis of lignite derivatives.The excellent performance of 10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) stems from the synergistic interaction between metallic and acidic sites.Specifically,the acidic sites generated by S_(2)O_(8)^(2-) facilitate the adsorption of O atoms in the substrate,whereas the metal sites optimize the process of hydrogen adsorption and activation and promote the generation of hydrogen radicals,which further enhances the ability to break C—O bonds.Thus,10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) exhibits more significantcatalytic activity compared to 10%Ni-ZrO_(2) prepared from pure ZrO_(2) as a support.Characterization results showed that the 10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) catalyst prepared by sodium borohydride reduction method presented a uniform pore structure,which effectively promoted the dispersion of metal Ni on the catalyst surface.Complete conversion of diphenyl ether(DPE)can be achieved under relatively mild conditions,and excellent hydrogenolysis activity is also demonstrated for other lignite derivatives containing C—O bonds.The possible reaction mechanism of DPE hydrogenolysis in the H_(2)-isopropanol system was investigated.This work represents a significantstep forward in the design of highly efficientsolid super acid catalysts.展开更多
The Pfitzinger reaction has long served as a notable synthesis pathway for quinoline-4-carboxylic acids.Although recognized for its synthetic potential since its discovery>138 years ago,a truly catalytic variant ha...The Pfitzinger reaction has long served as a notable synthesis pathway for quinoline-4-carboxylic acids.Although recognized for its synthetic potential since its discovery>138 years ago,a truly catalytic variant has remained elusive until now.Herein,we present a novel 2-tert-butyl-1,1,3,3-tetramethylguanidine(BTMG)-catalyzed Pfitzinger reaction that employs N-[(α-trifluoromethyl)vinyl]isatins with amines and alcohols,providing direct routes to 2-CF_(3)-quinoline-4-carboxamides and carboxylic esters.This method is not only green and environmentally benign but also accommodates the introduction of other functional groups like CF_(2)H and CO_(2)Me at the C2 position of quinoline skeleton.The utility of this methodology was demonstrated by the broad substrate scope,the late-stage modification of commercial drugs,and the diverse derivatization of quinoline framework.More importantly,this work not only opens up a new avenue for the activation of amide C-N bonds in catalytic reaction development,but also unlocks the huge potential of some 2-trifluoromethyl quinolines with strong inhibitory activity against PTP1B or optoelectronic application in organic light-emitting diodes.展开更多
Anisotropic surface broken bond densities of six different surfaces of calcite and three surfaces of fluorite were calculated. In terms of the calculated results, the commonly exposed surfaces of the two minerals were...Anisotropic surface broken bond densities of six different surfaces of calcite and three surfaces of fluorite were calculated. In terms of the calculated results, the commonly exposed surfaces of the two minerals were predicted and the relations between surface broken bonds densities and surface energies were analyzed. Then the anisotropic wettability of the commonly exposed surfaces was studied by means of contact angle measurement. The calculation results show that the （101^-4）, （213^-4）and （01 1^-8）surfaces for calcite and （111） for fluorite are the most commonly exposed surfaces and there is a good rectilinear relation between surface broken bond density and surface energy with correlation of determination （R^2） of 0.9613 and 0.9969, respectively. The anisotropic wettability of different surfaces after immersing in distilled water and sodium oleate solutions at different concentrations can be explained by anisotropic surface broken bond densities and active Ca sites densities, respectively.展开更多
基金Financial support from National Natural Science Foundation of China(Nos.21877043,21702068,21772050,22025102)the Fundamental Research Funds for the Central Universities,HUST(Nos.2019kfyXKJC080,2019JYCXJJ046)Huazhong University of Science and Technology are greatly appreciated。
文摘A sulfonium ylide participated alkylation and arylation under transition-metal free conditions is described.The disparate reaction pattern allowed the separate activation of non-ylidic S-alkyl and S-aryl bond.Under acidic conditions,sulfonium ylides serve as alkyl cation precursors which facilitate the alkylations.While under alkaline conditions,cleavage of non-ylidic S-aryl bond produces O-arylated compounds efficiently.The robustness of the protocols were established by the excellent compatibility of wide variety of substrates including carbohydrates.
文摘A concise approach to the synthesis of organoiron intermediate from organoboron and Fe(III)has been developed,and the reactivity of the intermediate with a series of electrophiles has been investigated.The results revealed that pinacol substituent of organoboron is crucial for C—B cleavage.The resulted organoiron intermediate is not stable,with weak nucleophicility.The coupling reactions of organoiron intermediate with acyl chlorides,anhydrides,isocyanates have been performed.
基金supported by the National Natural Science Foundation of China(No.52403035)the Shanghai Sailing Program(23YF1400300)+1 种基金the Fundamental Research Funds for the Central Universities(2232023D-05)the Weiqiao Teaching and Research Innovation Program.
文摘The lack of macro-continuity and mechanical strength of covalent organic frameworks(COFs)has significantly limited their practical applications.Here,we propose an“alcohol-triggered defect cleavage”strategy to precisely regulate the growth and stacking of COF grains through a moderate reversed Schiff base reaction,realizing the direct synthesis of COF nanofibers(CNFs)with high aspect ratio(L/D=103.05)and long length(>20μm).An individual CNF exhibits a biomimetic scale-like architecture,achieving superior flexibility and fatigue resistance under dynamic bending via a multiscale stress dissipation mechanism.Taking advantages of these structural features,we engineer CNF aerogels(CNF-As)with programmable porous structures(e.g.,honeycomb,lamellar,isotropic)via directional ice-template methodology.CNF-As demonstrate 100%COF content,high specific surface area(396.15 m^(2)g^(-1))and superelasticity(~0%elastic deformation after 500 compression cycles at 50%strain),outperforming most COF-based counterparts.Compared with the conventional COF aerogels,the unique structural features of CNF-A enable it to perform outstandingly in uranium extraction,with an 11.72-fold increment in adsorption capacity(920.12 mg g^(-1))and adsorption rate(89.9%),and a 2.48-fold improvement in selectivity(U/V=2.31).This study provides a direct strategy for the development of next-generation COF materials with outstanding functionality and structural robustness.
基金Research suppordet by the Foundation of the President of the Chinese Academy of Sciences, the Foundation of Institute Directors of the Chinese Academy of Sciences and the Shanghai National Laboratory of Plant Genetics of the Chinese Academy of Sciences.
文摘Based upon computer-assisted predictions on the secondary structures of tobacco mosaicvirus (TMV) genomic RNA (both polarities), hammerhead type ribozymes were synthesizedin vitro, which all shared a conserved domain adapted from satellite tobacco ringspot virus(sTobRV)RNA. Ribozymes RZ1, RZ2 and RZ3 were designed to cleave the phosphodiester bondsimmediate to the 3'--end of GUC between the residues 5384-5385 and 6312--6313 on the plusstrand and 1214-1215 on the minus strand, respectively. The in vitro data indicated that RZ1 wasable to cleave completely its substrates BT1(+ ) and BT2(+ ), representing partial sequencesof the plus strand of the TMV MP region at 50, 37 and 30℃ with a molar ratio of ribozymeto the target as low as 1:1. Its two iso-ribozymes RZ1A and RZ1B which were respectivelymodified to contain a CUUCGG sequence in the conserved region and in an additional 3'-ter-minal stem-loop of UUUUUCUUCGGAAAAA were able to cleave BT1(+) and BT2(+) asefficiently as RZ1. Ribozyme RZ3 cleaved, with less efficiency, its substrate BT2(-), repre-senting the minus strand of the TMV MP gene at 50, 37 or 30℃ even with a molar ratio ofribozyme to the target as high as 4:1. Ribozyme RZ2, however, had not any visible activityto its substrate BT3(+ ), representing the sequence was involved in the 3'--terminal tRNA--likesequence even though it was incubated for 5 min at 65℃ before being exposed to the ribozyme.
基金supported by the funding from the Key Laboratory of Alzheimer's Disease of Zhejiang Province and Oujiang Laboratory (W.S.)and National Natural Science Foundation of China:82301615 (M.X.)Q.Z.was the recipient of UBC Four Year Doctoral Fellowship and DMCBH Innovation Fund Graduate Trainee AwardM.X.is the funding recipient from the China Postdoctoral Science Foundation (grant no,2022M712435).
文摘Mutations in the Contactin-associated protein-like 2(CNTNAP2)gene are associated with autism spectrum disorder(ASD),and ectodomain shedding of the CNTNAP2 protein plays a role in its function.However,key enzymes involved in the C-terminal cleavage of CNTNAP2 remain largely unknown,and the effect of ASD-associated mutations on this process and its role in ASD pathogenesis remain elusive.In this report we showed that CNTNAP2 undergoes sequential cleavages by furin,ADAM10/17-dependent a-secretase and presenilindependent y-secretase.We identified that the cleavage sites of ADAM10 and ADAM17 in CNTNAP2 locate at its C-terminal residue I79 and L96,and the main a-cleavage product C79 by ADAM10 is required for the subsequent y-secretase cleavage to generate CNTNAP2 intracellular domain(CICD).ASD-associated CNTNAP2 mutations impair the a-cleavage to generate C79,and the inhibition leads to ASDIlike repetitive and social behavior abnormalties in the Cntnap2l1254T knock-in mice.Finaly,exogenous expression of 79 improves autism-ike phenotypes in the Cntnap2^(11254T) knock-in and Cntnap2^(-/-)knockout mice.This data demonstrates that the a-secretase is essential for CNTNAP2 processing and its function.Our study indicates that inhibition of the cleavage by pathogenic mutations underlies ASD pathogenesis,and upregulation of its C-terminal fragments could have therapeutical potentials for ASD treatment.
基金supported by grants from the National Natural Science Foundation of China(No.82273770)the Foundation for Innovative Research Groups of the National Natural Science Foundation of Sichuan Province(No.24NSFTD0051).
文摘In the realm of drug discovery,recent advancements have paved the way for innovative approaches and methodologies.This comprehensive review encapsulates six distinct yet interrelated mini-reviews,each shedding light on novel strategies in drug development.(a)The resurgence of covalent drugs is highlighted,focusing on the targeted covalent inhibitors(TCIs)and their role in enhancing selectivity and affinity.(b)The potential of the quantum mechanics-based computational aid drug design(CADD)tool,Cov_DOX,is introduced for predicting protein-covalent ligand binding structures and affinities.(c)The scaffolding function of proteins is proposed as a new avenue for drug design,with a focus on modulating protein-protein interactions through small molecules and proteolysis targeting chimeras(PROTACs).(d)The concept of pro-PROTACs is explored as a promising strategy for cancer therapy,combining the principles of prodrugs and PROTACs to enhance specificity and reduce toxicity.(e)The design of prodrugs through carbon-carbon bond cleavage is discussed,offering a new perspective for the activation of drugs with limited modifiable functional groups.(f)The targeting of programmed cell death pathways in cancer therapies with small molecules is reviewed,emphasizing the induction of autophagy-dependent cell death,ferroptosis,and cuproptosis.These insights collectively contribute to a deeper understanding of the dynamic landscape of drug discovery.
基金supported by the National Natural Science Foundation of China(22472023,22202037)the Jilin Province Science and Technology Development Program(20250102077JC)the Fundamental Research Funds for the Central Universities(2412024QD014,2412023QD019).
文摘Direct ethanol fuel cells(DEFCs)are a promising alternative to conventional energy sources,offering high energy density,environmental sustainability,and operational safety.Compared to methanol fuel cells,DEFCs exhibit lower toxicity and a more mature preparation process.Unlike hydrogen fuel cells,DEFCs provide superior storage and transport feasibility,as well as cost-effectiveness,significantly enhancing their commercial viability.However,the stable C-C bond in ethanol creates a high activation energy barrier,often resulting in incomplete electrooxidation.Current commercial platinum(Pt)-and palladium(Pd)-based catalysts demonstrate low C-C bond cleavage efficiency(<7.5%),severely limiting DEFC energy output and power density.Furthermore,high catalyst costs and insufficient activity impede large-scale commercialization.Recent advances in DEFC anode catalyst design have focused on optimizing material composition and elucidating catalytic mechanisms.This review systematically examines developments in ethanol electrooxidation catalysts over the past five years,highlighting strategies to improve C1 pathway selectivity and C-C bond activation.Key approaches,such as alloying,nanostructure engineering,and interfacial synergy effects,are discussed alongside their mechanistic implications.Finally,we outline current challenges and future prospects for DEFC commercialization.
基金supported by the National Key R&D Program of China (No. 2021YFE0104900)Guangdong Basic and Applied Basic Research Foundation (No. 2023A1515030018)
文摘The valorization of biomass to produce biofuels has become a heavily investigated field due to the depletion of fossil fuels and environmental concerns.Among them,the research on deoxygenation of fatty acids or esters derived from biomass as well as municipal sludge organics to produce diesel-like hydrocarbons has become a hot topic.Fatty acid is a key intermediate derived from ester hydrolysis,therefore has attracted more attention as a model compound.In this review,we first introduce and compare the three reaction pathways of hydrodeoxygenation,decarboxylation and decarbonylation,for the deoxygenation of fatty acids and esters.The preference of reaction pathway is closely related to the type of raw materials and catalysts as well as reaction conditions.The special purpose of this review is to summarize the dilemma and possible strategies for deoxygenation of fatty acids,which is expected to provide guidance for future exploration and concentrates.The atom utilization along with stability during reaction in a long time is the most important index for commercial economy.Herein,we propose that the rational design and delicate synthesis of stable single-atom non-noble catalysts may be the best solution.The ultimately goal is aiming to develop sustainable production of green diesel hydrocarbons.
基金partly supported by the National Natural Science Foundation of China(No.22301108)the Project Startup Foundation for Distinguished Scholars of Jiangsu University(Nos.4111310026 and 5501310014).
文摘Novel benzo-bridged hexaphyrin(2.1.2.1.2.1)and its copper complex were synthesized.Single-crystal structures showed typical figure-of-eight Huckel topologies.NMR,NICS,HOMA,ACID,and EDDB analysis supported their non-aromatic properties owning to the strong local aromatic benzo rings cutting the global aromatic ring of the benzo-bridged figure-of-eight hexaphyrin(2.1.2.1.2.1).The redox properties and degenerate HOMOs and LUMOs levels indicate multielectron donating and accepting abilities.
基金financially supported by the Young Scientists Fund of the National Natural Science Foundation of China(No.22305173)Young Scientists Fund of the Natural Science Foundation of Tianjin(No.S25QNM009)+2 种基金Tianjin University Independent Innovation Fund(No.2025XSU-0008)the National Natural Science Foundation of China(No.22475151)Xiaomi Young Talents Program。
文摘Ultrasound(US),as an efficient and non-invasive trigger,has been extensively explored in drug delivery and has many advantages,such as deep penetration,low invasiveness,and high biochemical precision.These advantages demonstrate the immense clinical potential of ultrasound.This study aimed to provide a comprehensive analysis of ultrasound-induced shear forces that exhibit covalent/non-covalent bond cleavage and reactive oxygen species(ROS)-mediated remote control of nanocarriers.By doing so,we can gain a deeper understanding of the vital role,significant advantages,and untapped potential of ultrasound in molecular-level drug activation.Furthermore,clinical translation faces challenges such as the low drug-loading capacity of polymer chains,frequency compatibility between ultrasound parameters and biological systems,insufficient ROS generation,and biocompatibility of current sonosensitizers.To solve these problems,ultrasound mechanochemistry has emerged as a versatile therapeutic modality to promote the development of medical treatments.
基金financially supported by the National Key Research and Development Program of China(No.2023YFD2200505)the National Natural Science Foundation of China(No.22202105)+3 种基金the Natural Science Foundation of Jiangsu Higher Education Institutions of China(No.21KJA150003)the Innovation and Entrepreneurship Team Program of Jiangsu Province(No.JSSCTD202345)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX23_1163)the China Postdoctoral Science Foundation(Nos.2023M731703 and 2024T170415)
文摘The oxidation of lignin model compounds to esters via C-C bond cleavage has attracted considerable attention,as esters could be used as important polymer precursors and pharmaceutical intermediates.However,most studies focus on designing homogeneous or noble metal catalysts and conducting the reactions under basic conditions.Here,we report an efficient process for the C-C bond cleavage of lignin model compounds and selectively producing esters over different shaped CeO_(2)(i.e.,nanospheres(S),nanorods(R),nanoparticles(P),and nanocubes(C))under base-free conditions.Specifically,the yield of methyl anisate from the aerobic oxidation of l-(4-methoxyphenyl)ethanol reaches 77.6%over CeO_(2)-S in one hour(91%in 9 h),exhibiting higher performance compared to other evaluated CeO_(2)catalysts(6.4%-40.2%).Extensivecharacterizations and experimental investigations reveal that the density of weak base sites and oxygen vacancies on the CeO_(2)surface is positively correlated with the yield of methyl esters.Furthermore,the reaction pathway is investigated,which confirms that 1-(4-methoxyphenyl)ethanol first undergoes two reactions(i.e.,etherification and dehydrogenation)to produce intermediates of1-methoxy-4-(1-methoxy-ethyl)-benzene and 1-(4-methoxyphenyl)ethanone,respectively,followed by a series of functional group transformations to generate the targeted methyl anisate ultimately.
基金financial support from National Natural Science Foundation of China(Nos.21801129,22078153 and22378201)National Key Research and Development Program of China(No.2022YFB3805603)+3 种基金Natural science research projects in Jiangsu Higher Education Institutions(No.18KJB150018)Open Research Fund of School of Chemistry and Chemical EngineeringHenan Normal University(No.2024Y16)Nanjing Tech University(Start-up Grant Nos.39837137,39837101 and 3827401739)for financial support。
文摘Pyridyl-based ketones and 1,6-diketones are both attractive and invaluable scaffolds which play pivotal roles in the construction and structural modification of a plethora of synthetically paramount natural products,pharmaceuticals,organic materials and fine chemicals.In this context,we herein demonstrate an unprecedented,robust and generally applicable synthetically strategy to deliver these two crucial ketone frameworks via visible-light-induced ring-opening coupling reactions of cycloalcohols with vinylazaarenes and enones,respectively.A plausible mechanism involves the selectiveβ-C-C bond cleavage of cycloalcohols enabled by proton-coupled electron transfer and ensuing Giese-type addition followed by single electron reduction and protonation.The synthetic methodology exhibits broad substrate scope,excellent functional group compatibility as well as operational simplicity and environmental friendliness.
文摘The efficient conversion of lignin into mono-cycloalkanes via both C–O and C–C bonds cleavage are attractive,but challenging due to the high C–C bond dissociation energy.Previous studies have demonstrated that NbO_(x)-based catalysts exhibited exceptional capabilities for C_(Ar)–C bond cleavage and broken the limitation of lignin monomers.In this work,we presented an economical multifunctional Pt-Nb/MOR catalyst that achieved an impressive monomer yield of 147%during the depolymerization and hydrodeoxygenation of lignin into mono-cycloalkanes.Reaction pathway studies showed that unlike traditional NbO_(x)-based catalytic system,bicyclohexane was an important intermediate in this system and followed the C_(sp3)–C_(sp3)cleavage pathway after complete cyclic-hydrogenation.Deep investigations demonstrated that the doping of Nb in Pt/MOR not only enhanced the activation of hydrogen by Pt,but also increased the acidity of MOR,both of these are favor for the hydrogenolytic cleavage of C_(sp3)–C_(sp3)bonds.This work provides a low-cost catalyst to obtain high-yield monomers from lignin under relatively mild conditions and would help to design catalysts with higher activity for the valorization of lignin.
文摘Lignin is the only largest renewable aromatic resource in nature.Currently,most lignin is underutilized for low-value applications due to the complex structure and recalcitrant chemical properties.Over the past decades,extensive research has been devoted to valorizing lignin into aromatic N-heterocycles in the presence of nitrogen sources.It overcomes the element limitation,expands the products portfolio and would play a momentous role in value-added biorefinery concept.In this review,the latest research progress in the synthesis of N-heterocyclic compounds from lignin,lignin model compounds,and lignin-derived monomers(phenols,aromatic alcohols,aldehydes,ketones,and ethers)is presented.According to the structural characteristics of the products,these achievements are classified by the construction of five-,six-,and seven-membered N-heterocyclic compounds through one-step,multi-step,or one-pot multi-step reactions.Furthermore,the tailor-designed routes and catalytic systems,along with the reaction mechanisms/pathways involved are entirely discussed to elucidate the challenges regarding the structural complexity of lignin,the incompatible catalysis for C–O cleavage and C–N formation,as well as the nitrogen-heterocyclic ring construction.The prospects,future research efforts and process developments for the refining of lignin into aromatic N-heterocyclic compounds are outlined in terms of economy,environmental friendliness,and safety so as to draw some guidelines for lignin valorization.
文摘Designing Fischer-Tropsch synthesis(FTS)catalysts to selectively produce liquid hydrocarbon fuels is a crucial challenge.Herein,we selectively introduced Co nanoparticles(NPs)into the micropores and mesopores of an ordered mesoporous MFI zeolite(OMMZ)through impregnation,which controlled the carbon number distribution in the FTS products by tuning the position of catalytic active sites in differently sized pores.The Co precursors coordinated by acetate with a size of 9.4×4.2×2.5Åand by 2,2'-bipyridine with a size of 9.5×8.7×7.9Å,smaller and larger than the micropores(ca.5.5Å)of MFI,made the Co species incorporated in OMMZ's micropores and mesopores,respectively.The carbon number products synthesized with the Co NPs confined in mesopores were larger than that in micropores.The high jet and diesel selectivities of 66.5%and 65.3%were achieved with Co NPs confined in micropores and mesopores of less acidic Na-type OMMZ,respectively.Gasoline and jet selectivities of 76.7%and 70.8%were achieved with Co NPs confined in micropores and mesopores of H-type OMMZ with Brönsted acid sites,respectively.A series of characterizations revealed that the selective production of diesel and jet fuels was due to the C-C cleavage suppressing of heavier hydrocarbons by the Co NPs located in mesopores.
基金supported by the Fundamental Research Funds for the Central Universities,Southwest Minzu University(ZYN2023097)Scientific and Technological Innovation Team for Qinghai-Xizang Plateau Research in Southwest Minzu University(2024CXTD13)。
文摘While variable regions of immunoglobulins are extensively diversified by V(D)J recombination and somatic hypermutation in vertebrates,the constant regions of immunoglobulin heavy chains also utilize certain mechanisms to produce diversity,including class switch recombination(CSR),subclass differentiation,and alternative expression of the same gene.Many species of birds,reptiles,and amphibians express a truncated isoform of immunoglobulin Y(IgY),termed IgY(ΔFc),which lacks theυCH3 andυCH4 domains.In Anseriformes,IgY(ΔFc)arises from alternative transcriptional termination sites within the sameυgene,whereas in some turtles,intact IgY and IgY(ΔFc)are encoded by distinct genes.Different from the previously reported IgY(ΔFc)variants,this study identified a truncated IgY in the snake Elaphe taeniura,characterized by the loss of only a portion of the CH4 domain.Western blotting and liquid chromatographytandem mass spectrometry confirmed that this truncated IgY is generated by post-translational cleavage at N338 within the IgY heavy chain constant(CH)region.Furthermore,both human and snake asparaginyl endopeptidase were shown to cleave snake IgY in vitro.These findings reveal a novel mechanism for the production of shortened IgY forms,demonstrating that the immunoglobulin CH region undergoes diversification through distinct strategies across vertebrates.
基金Project supported by the National Natural Science Foundation of China(22221001,22131007,22102193)the National Key R&D Program of China(2021YFA1501101,2022YFA1504601)+1 种基金the 111 Project(B20027)a Startup Program of the State Key Laboratory for Oxo Synthesis and Selective Oxidation of LICP(EOSX0184)。
文摘Heterogeneous precious metal catalysts are prone to agglomeration during preparation,requiring high usage with consequently high costs.Maximizing the efficiency of precious-metal utilization is of great significance in the design of supported precious metal catalysts.Herein,2,2'-bipyridyl-5,5'-dicarboxylic acid was used as the ligand in constructing the UiO-67-Ce-BPyDC framework with Ce^(4+)coordination.This framework enables precise adsorption and coordination of Pd2+at the nitrogen sites of pyridine,promoting high dispersion of the Pd species at a single site,thereby facilitating controlled palladium loading.This precursor was used to fabricate supported Pd-based catalysts on CeO_(2)(Pd-N/CeO_(2)-P)via pyrolysis.Notably,because the Pd species are homogeneously distributed on CeO_(2)with strong interactions,Pd-N/CeO_(2)-P exhibits remarkable efficiency in cleaving the C-O bonds of diphenyl ether(DPE)to produce cyclohexanol,with a selectivity of 72.1%.The origin of the high selectivity of cyclohexanol is further elucidated using theoretical calculations;that is,DPE undergoes not only hydrogenolysis on Pd-N/CeO_(2)-P,but also hydrolysis to produce more cyclohexanol.This study not only demonstrates a successful strategy for designing highly dispersed metal catalysts,but also underscores the importance of such tailored catalysts in the advancement of sustainable lignin depolymerization technologies.
基金supported by the National Key Research and Development Program of China(2022YFB4101100)the National Natural Science Foundation of China(22178375 and 22478414)the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Catalytic aryl ether C—O bonds hydrogenolysis was an important route to convert lignite into high valueadded chemicals.Solid super acid 10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) catalysts were successfully synthesized and evaluated their performance in catalytic hydrolysis of lignite derivatives.The excellent performance of 10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) stems from the synergistic interaction between metallic and acidic sites.Specifically,the acidic sites generated by S_(2)O_(8)^(2-) facilitate the adsorption of O atoms in the substrate,whereas the metal sites optimize the process of hydrogen adsorption and activation and promote the generation of hydrogen radicals,which further enhances the ability to break C—O bonds.Thus,10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) exhibits more significantcatalytic activity compared to 10%Ni-ZrO_(2) prepared from pure ZrO_(2) as a support.Characterization results showed that the 10%Ni-S_(2)O_(8)^(2-)=ZrO_(2) catalyst prepared by sodium borohydride reduction method presented a uniform pore structure,which effectively promoted the dispersion of metal Ni on the catalyst surface.Complete conversion of diphenyl ether(DPE)can be achieved under relatively mild conditions,and excellent hydrogenolysis activity is also demonstrated for other lignite derivatives containing C—O bonds.The possible reaction mechanism of DPE hydrogenolysis in the H_(2)-isopropanol system was investigated.This work represents a significantstep forward in the design of highly efficientsolid super acid catalysts.
基金National Natural Science Foundation of China(Nos.22171056,22122402,21801050)Outstanding Youth Project of Guangdong Natural Science Foundation(Nos.2024B1515020036,2021B1515020048)+3 种基金Guangdong Natural Science Foundation(Nos.2023A1515011313,2021A1515010510,2024A1515030037)Tertiary Education Scientific Research Project of Guangzhou Municipal Education Bureau(No.202235305)the Open Fund from Key Laboratory of Organofluorine ChemistryShanghai Engineering Research Center of Molecular Therapeutics and New Drug Development are gratefully acknowledged for financial support.
文摘The Pfitzinger reaction has long served as a notable synthesis pathway for quinoline-4-carboxylic acids.Although recognized for its synthetic potential since its discovery>138 years ago,a truly catalytic variant has remained elusive until now.Herein,we present a novel 2-tert-butyl-1,1,3,3-tetramethylguanidine(BTMG)-catalyzed Pfitzinger reaction that employs N-[(α-trifluoromethyl)vinyl]isatins with amines and alcohols,providing direct routes to 2-CF_(3)-quinoline-4-carboxamides and carboxylic esters.This method is not only green and environmentally benign but also accommodates the introduction of other functional groups like CF_(2)H and CO_(2)Me at the C2 position of quinoline skeleton.The utility of this methodology was demonstrated by the broad substrate scope,the late-stage modification of commercial drugs,and the diverse derivatization of quinoline framework.More importantly,this work not only opens up a new avenue for the activation of amide C-N bonds in catalytic reaction development,but also unlocks the huge potential of some 2-trifluoromethyl quinolines with strong inhibitory activity against PTP1B or optoelectronic application in organic light-emitting diodes.
基金Project (50834006) supported by the National Natural Science Foundation of ChinaProject (CX2011B122) supported by Hunan Provincial Innovation Foundation for PostgraduateProject (2011ybjz045) supported by Graduate Degree Thesis Innovation Foundation of Central South University
文摘Anisotropic surface broken bond densities of six different surfaces of calcite and three surfaces of fluorite were calculated. In terms of the calculated results, the commonly exposed surfaces of the two minerals were predicted and the relations between surface broken bonds densities and surface energies were analyzed. Then the anisotropic wettability of the commonly exposed surfaces was studied by means of contact angle measurement. The calculation results show that the （101^-4）, （213^-4）and （01 1^-8）surfaces for calcite and （111） for fluorite are the most commonly exposed surfaces and there is a good rectilinear relation between surface broken bond density and surface energy with correlation of determination （R^2） of 0.9613 and 0.9969, respectively. The anisotropic wettability of different surfaces after immersing in distilled water and sodium oleate solutions at different concentrations can be explained by anisotropic surface broken bond densities and active Ca sites densities, respectively.
