Block of proliferation 1(BOP1)is a key protein involved in ribosome maturation and affects cancer progression.However,its role in gastric cancer(GC)remains unknown.This study aimed to explore the expression of BOPI in...Block of proliferation 1(BOP1)is a key protein involved in ribosome maturation and affects cancer progression.However,its role in gastric cancer(GC)remains unknown.This study aimed to explore the expression of BOPI in GC and its potential mechanisms in regulating GC growth,and the relationship between BOP1 level in cancer tissues and survival was also analyzed.The expression of BOPI was examined by immunohistochemistry(IHC)in a cohort containing 387 patients with primary GC.Cultured GC cells were treated by siRNA to knock down the BOP1 expression,and examined by CCK-8 assay and plate clone formation to assess cell proliferation in vitro.Apoptotic rate of cultured GC cells was detected by flow cytometry with double staining of AnnxinV/PI.The xenografted mouse model was used to assess GC cell proliferation in vivo.Western blot and IHC were also performed to detect the expression levels of BOP1,p53 and p21.Patients with higher level of BOP1 in cancer tissues had significantly poorer survival.BOP1 silencing signifcantly suppressed GC cell proliferation both in vitro and in vivo.It blocked cell cycle at G0/G1 phase and led to apoptosis of GC cells via upregulating p53 and p21.BOP1 silencing-induced suppression of cell proliferation was partly reversed by pifithrin-a,(a p53 inhibitor).Our study dermonstrated that BOP1 up-regulation may be a hallmark of GC and it may regulate proliferation of GC cells by activating p53.BOP1 might be considered a novel biomarker of GC proliferation,and could be a potential indicator of prognosis of GC patients.BOP1 might also be a potential target for the treatment of GC patients if further researched.展开更多
HIV-specific chimeric antigen receptor(CAR)T-cells have been developed to target HIV-1 infected CD4t T-cells that express HIV Env proteins.However,T cell exhaustion and the patient-specific autologous paradigm of CAR-...HIV-specific chimeric antigen receptor(CAR)T-cells have been developed to target HIV-1 infected CD4t T-cells that express HIV Env proteins.However,T cell exhaustion and the patient-specific autologous paradigm of CAR-T cell hurdled clinical applications.Here,we created HIV-specific CAR-T cells using human peripheral blood mononuclear cells and a 3BNC117-E27(3BE)CAR construct that enabled the expression of programmed cell death protein(PD-1)-blocking scFv E27 and the single-chain variable fragment of the HIV-1-specific broadly neutralizing antibody 3BNC117 to target native HIV Env.Compared with T cells expressing 3BNC117-CAR alone,3BE CAR-T cells showed greater cytotoxic activity against HIV Envt cells with stronger proliferation capability,higher killing efficiency,and enhanced cytokine secretion in the presence of HIV Env-expressing cells.Furthermore,we manufactured TCR-deficient 3BE CAR-T cells through gene editing and demonstrated that these CAR-T cells could effectively kill HIV Env^(+) cells in vivo without the occurrence of severe graft-versus-host disease(GvHD)in NSG mice.These data suggest that we have provided a feasible approach to the generation of“off-theshelf”anti-HIV CAR-T cells in combination with PD-1 checkpoint blockade immunotherapy,which can be a powerful therapeutic candidate for the functional cure of HIV.展开更多
Blue InGaN light-emitting diodes （LEDs） with a conventional electron blocking layer （EBL）, a common n-A1GaN hole blocking layer （HBL）, and an n-A1GaN HBL with gradual A1 composition are investigated numerically,...Blue InGaN light-emitting diodes （LEDs） with a conventional electron blocking layer （EBL）, a common n-A1GaN hole blocking layer （HBL）, and an n-A1GaN HBL with gradual A1 composition are investigated numerically, which involves analyses of the carrier concentration in the active region, energy band diagram, electrostatic field, and internal quantum efficiency （IQE）. The results indicate that LEDs with an n-AIGaN HBL with gradual AI composition exhibit better hole injection efficiency, lower electron leakage, and a smaller electrostatic field in the active region than LEDs with a conven tional p-A1GaN EBL or a common n-A1GaN HBL. Meanwhile, the efficiency droop is alleviated when an n-A1GaN HBL with gradual A1 composition is used.展开更多
BACKGROUND M1 polarization of macrophages is an important pathological process in myocardial ischemia reperfusion injury, which is the major obstacle for the treatment of acute myocardial infarction. Currently, the st...BACKGROUND M1 polarization of macrophages is an important pathological process in myocardial ischemia reperfusion injury, which is the major obstacle for the treatment of acute myocardial infarction. Currently, the strategies and mechanisms of inhibiting M1 polarization are poorly explored. This study aims to investigate the role of soluble death receptor 5-Fc(s DR5-Fc) in regulating M1 polarization of macrophages under extreme conditions and explore the mechanisms from the aspect of glycolysis.METHODS Extreme conditions were induced in RAW264.7 cells. Real-time quantitative polymerase chain reaction and western blot were used to detect the expression of m RNA and proteins, respectively. Cell counting kit-8 was used to investigate the proliferation activity of cells. Expression levels of inflammatory cytokines were determined by enzyme-linked immunosorbent assay.RESULTS We found that s DR5-Fc rescues the proliferation of macrophages under extreme conditions, including nutrition deficiency, excessive peroxide, and ultraviolet irradiation. In addition, administration of s DR5-Fc inhibits the M1 polarization of macrophages induced by lipopolysaccharide(LPS) and interferon-gamma(IFN-γ), as the expression of M1 polarization markers CD86, CXC motif chemokine ligand 10, matrix metalloproteinase 9, and tumor necrosis factor-α, as well as the secretion of inflammatory factors interleukin(IL)-1β and IL-6, were significantly decreased. By further investigation of the mechanisms, the results showed that s DR5-Fc can recover the LPS and IFN-γ induced p H reduction, lactic acid elevation, and increased expression of hexokinase 2 and glucose transporter 1, which were markers of glycolysis in macrophages.CONCLUSIONS s DR5-Fc inhibits the M1 polarization of macrophages by blocking the glycolysis, which provides a new direction for the development of strategies in the treatment of myocardial ischemia reperfusion injury.展开更多
Currently,limited studies of immiscible water-alternating-CO_(2)(imWACO_(2))flooding focus on the impact of reservoir heterogeneity on reservoir development outcomes.Given this,using the heterogeneous reservoirs in th...Currently,limited studies of immiscible water-alternating-CO_(2)(imWACO_(2))flooding focus on the impact of reservoir heterogeneity on reservoir development outcomes.Given this,using the heterogeneous reservoirs in the Gao 89-1 block as a case study,this study conducted slab core flooding experiments and numerical simulations to assess the impact of reservoir heterogeneity on imWACO_(2)flooding efficiency.It can be concluded that imWACO_(2)flooding can enhance the sweep volume and oil recovery compared to continuous CO_(2)flooding.As the permeability difference increases,the difference in the swept volume between zones/layers with relatively high and low permeability increases.To optimize the exploitation of reservoirs in the Gao 89-1 block,the optimal timing and CO_(2)injection rate for imWACO_(2)flooding are determined at water cut of 40%and 10000 m^(3)/d,respectively.A short injection-production semi-period,combined with multiple cycles of water and CO_(2)injection alternations,is beneficial for enhanced oil recovery from imWACO_(2)flooding.展开更多
The efficient construction of valuable N-heterocycles is one of the most important tasks in organic synthesis.Pyrrolo[2,3-b]indoles represent a privileged skeleton,which are extensively found in natural products,pharm...The efficient construction of valuable N-heterocycles is one of the most important tasks in organic synthesis.Pyrrolo[2,3-b]indoles represent a privileged skeleton,which are extensively found in natural products,pharmaceuticals and luminescent materials.Nevertheless,their synthesis suffers from pre-functionalized starting materials and multi-step synthesis.On the other hand,despite significant progress in isocyanide insertions.展开更多
We developed a novel Pd-catalyzed carbonylation of ortho-alkenyl iodobenzenes with co,affording a diverse array of 3-arylindenones in good to excellent yields(up to 94%yield).This methodology exhibits broad substrate ...We developed a novel Pd-catalyzed carbonylation of ortho-alkenyl iodobenzenes with co,affording a diverse array of 3-arylindenones in good to excellent yields(up to 94%yield).This methodology exhibits broad substrate scope and good functional group compatibility.The synthetic utility was demonstrated by a gram-scale reaction,diverse product derivatizations,and the preparation of an intermediateforaPPARyagonist.展开更多
This work describes an effective Pd-catalyzed isomerization-hydroformylation of internal olefins with HCO_(2)H and N-formylsaccharin,providing a wide variety of linear aldehydes in up to 72%yield with up to 18:1 l/b r...This work describes an effective Pd-catalyzed isomerization-hydroformylation of internal olefins with HCO_(2)H and N-formylsaccharin,providing a wide variety of linear aldehydes in up to 72%yield with up to 18:1 l/b ratio.The olefin substrate can bear various functional groups.Conjugated olefins can also be efficiently isomerized and hydroformylated.The reaction is easy to operate and requires no handling of CO and H_(2).To the best of our knowledge,the current process represents the first example for Pd-catalyzed efficient isomerization-hydroformylation process of internal olefins to predominately give linear aldehydes.展开更多
Comprehensive Summary.The use of CO_(2) as a renewable C1 source for the synthesis of value-added chemicals can contribute to a more sustainable chemistry.In this work,a nickel-catalyzed amide-directed carboxylation o...Comprehensive Summary.The use of CO_(2) as a renewable C1 source for the synthesis of value-added chemicals can contribute to a more sustainable chemistry.In this work,a nickel-catalyzed amide-directed carboxylation of aryl C−F bonds with CO_(2) has been developed.The reaction is switchable controlled by LiCl to react with one or two molecules of CO_(2) to afford valuable phthalimides orα-hydroxycarboxylic acid derivatives.Further study shows that the reaction is a step-by-step process.The first step is a nickel-catalyzed carboxylation of aryl C−F bonds with CO_(2) and tandem cyclization to afford phthalimides.The second step is a nickel-catalyzed C−N bond carboxylation of phthalimides with CO_(2),and intramolecular nucleophilic addition of amide anion to the carbonyl.The carboxylation of phthalimides with CO_(2) is also developed based on this reaction.The work features inert C−F bond functionalization,amide C−N bond activation,and multiple CO_(2) incorporation.Mechanistic studies indicate that the azanickelacycle intermediates play an important role,and LiCl facilitates the reduction of Ni(II)to Ni(I)and promotes the carboxylation with the second molecule of CO_(2).This protocol provides an efficient route for C−F bond functionalization under mild conditions via the chemical fixation of one or two molecules of CO_(2).展开更多
This review provides a comprehensive summary of progress to date in the utilization of rongalite as a versatile reagent in organic synthesis,with a focus on recent researches.The contents have been organized according...This review provides a comprehensive summary of progress to date in the utilization of rongalite as a versatile reagent in organic synthesis,with a focus on recent researches.The contents have been organized according to the functions exhibited by rongalite.Reaction mechanisms are provided,demonstrating the multifaceted roles of this compound in various transformations,including as a sulfone,C1 or masked proton source and as a single electron donor or reducing agent.展开更多
Eight zwitterionic rare earth metal complexes stabilized by amino-bridged tris(phenolato)ligands bearing quaternary ammonium side-arms were synthesized and characterized.These complexes were used as single-component c...Eight zwitterionic rare earth metal complexes stabilized by amino-bridged tris(phenolato)ligands bearing quaternary ammonium side-arms were synthesized and characterized.These complexes were used as single-component catalysts for the cycloaddition of CO_(2)and epoxides,and their catalytic activities are obviously higher than those of their binary analogues.Further studies revealed that the halide anions(Cl^(–),Br^(–),I^(–))and the metal complexes influenced the catalytic activity,and the lanthanum complex bearing iodide anion showed the highest catalytic activity for this addition reaction.A variety of mono-substituted epoxides were converted to cyclic carbonates in good to excellent yields(55%—99%)with high selectivity(>99%)at 30℃and 1 bar CO_(2),whereas internal epoxides required higher both reaction temperatures(60—120℃)and catalyst loading(2 mol%)for high yields.The catalyst was recyclable for four times without noticeable loss of catalytic activity.Based on the results of kinetic studies and in℃situ IR reactions,a plausible reaction mechanism was proposed.展开更多
Poly(3-hydroxyalkanoates) (PHAs) are a promising class of biodegradable polymers,exhibiting properties comparable to traditional petroleum-based counterparts.Nonetheless,the widespread commercialization of PHAs is hin...Poly(3-hydroxyalkanoates) (PHAs) are a promising class of biodegradable polymers,exhibiting properties comparable to traditional petroleum-based counterparts.Nonetheless,the widespread commercialization of PHAs is hindered by the absence of an efficient and economically viable catalytic system,impeding their competitiveness against non-biodegradable polymers.In an effort to address this challenge,we present a study on a newly developed chloro-bridged dimeric salphen zirconium cobaltate complex for the direct synthesis of PHAs via carbonylative polymerization of epoxides.The catalytic system demonstrates favorable activity under mild reaction conditions,enabling complete monomer conversion and an impressive 92% selectivity towards PHA formation.Through meticulous control experiments and mechanistic studies,we have gained crucial insights into the polymerization process.Remarkably,our findings challenge the prevailing notion of sequential ring-opening polymerization of in-situ generated β-lactones as the primary pathway.Instead,we demonstrate that the polymerization predominantly proceeds through direct co-polymerization of epoxide and carbon monoxide,unveiling a unique and efficient mechanism for PHA synthesis.展开更多
We reported for the first time that ethyl bromodifluoroacetate directly reacts with azaindole without transition metal catalysis to produce a difluoromethyl protected 5-aldehyde group product in one step.It is worth m...We reported for the first time that ethyl bromodifluoroacetate directly reacts with azaindole without transition metal catalysis to produce a difluoromethyl protected 5-aldehyde group product in one step.It is worth mentioning that the reacted aldehyde group is only formed at the 5 position.In addition,this method has good substrate applicability and functional group tolerance.Finally,we also carried out some mechanism auxiliary experiments,which confirmed that the aldehyde-based carbon comes from ethyl bromodifluoroacetate.展开更多
A highly selective palladium-catalyzed carbonylation of 2-alkynylanilines bearing an amide moiety to condensed six-membered heterocyclic structures has been developed under mild conditions(room temperature and atmosph...A highly selective palladium-catalyzed carbonylation of 2-alkynylanilines bearing an amide moiety to condensed six-membered heterocyclic structures has been developed under mild conditions(room temperature and atmospheric pressure of CO).The carbonylative protocol is also compatible with CO surrogates,such as benzene-1,3,5-triyl triformate(TFBen)or the newly developed calix[6]arenes functionalized with six formate groups(CLX[6]CO),which are both capable to release CO in situ.A series of tricyclic fused heterocycles containing the important oxazino-quinolinone scaffold have been selectively obtained(only the 6-endo-dig cyclization mode has been observed)in good to excellent yields(up to 99%).展开更多
A deuterated methylthiolating reagent with a broad spectrum,designated as DMTp,has been ingeniously formulated.This new reagent can be produced with high efficiency through the simple combination of commercially avail...A deuterated methylthiolating reagent with a broad spectrum,designated as DMTp,has been ingeniously formulated.This new reagent can be produced with high efficiency through the simple combination of commercially available methyl 3-thiopropanoate and CD_(3)l.This novel SCD_(3) reagent exhibits excellent reactivity with electrophiles such as alkyl iodides,benzyl chlorides,aryl halides(l,Br)and aryl triflates,resulting in high levels of deuterium content(99%D).Representative deuterated methylthiolated biomolecules,such as Sulfoxaflor,havebeen synthesizedforuse in pharmaceutical discoveryand development.展开更多
基金supported by National Natural Science Foundation of China(No.31670806)。
文摘Block of proliferation 1(BOP1)is a key protein involved in ribosome maturation and affects cancer progression.However,its role in gastric cancer(GC)remains unknown.This study aimed to explore the expression of BOPI in GC and its potential mechanisms in regulating GC growth,and the relationship between BOP1 level in cancer tissues and survival was also analyzed.The expression of BOPI was examined by immunohistochemistry(IHC)in a cohort containing 387 patients with primary GC.Cultured GC cells were treated by siRNA to knock down the BOP1 expression,and examined by CCK-8 assay and plate clone formation to assess cell proliferation in vitro.Apoptotic rate of cultured GC cells was detected by flow cytometry with double staining of AnnxinV/PI.The xenografted mouse model was used to assess GC cell proliferation in vivo.Western blot and IHC were also performed to detect the expression levels of BOP1,p53 and p21.Patients with higher level of BOP1 in cancer tissues had significantly poorer survival.BOP1 silencing signifcantly suppressed GC cell proliferation both in vitro and in vivo.It blocked cell cycle at G0/G1 phase and led to apoptosis of GC cells via upregulating p53 and p21.BOP1 silencing-induced suppression of cell proliferation was partly reversed by pifithrin-a,(a p53 inhibitor).Our study dermonstrated that BOP1 up-regulation may be a hallmark of GC and it may regulate proliferation of GC cells by activating p53.BOP1 might be considered a novel biomarker of GC proliferation,and could be a potential indicator of prognosis of GC patients.BOP1 might also be a potential target for the treatment of GC patients if further researched.
基金funded by the National Natural Science Foundation of China(81761128020 and 82041001)the National Grand Program on Key Infectious Diseases(2017ZX10202102-002).
文摘HIV-specific chimeric antigen receptor(CAR)T-cells have been developed to target HIV-1 infected CD4t T-cells that express HIV Env proteins.However,T cell exhaustion and the patient-specific autologous paradigm of CAR-T cell hurdled clinical applications.Here,we created HIV-specific CAR-T cells using human peripheral blood mononuclear cells and a 3BNC117-E27(3BE)CAR construct that enabled the expression of programmed cell death protein(PD-1)-blocking scFv E27 and the single-chain variable fragment of the HIV-1-specific broadly neutralizing antibody 3BNC117 to target native HIV Env.Compared with T cells expressing 3BNC117-CAR alone,3BE CAR-T cells showed greater cytotoxic activity against HIV Envt cells with stronger proliferation capability,higher killing efficiency,and enhanced cytokine secretion in the presence of HIV Env-expressing cells.Furthermore,we manufactured TCR-deficient 3BE CAR-T cells through gene editing and demonstrated that these CAR-T cells could effectively kill HIV Env^(+) cells in vivo without the occurrence of severe graft-versus-host disease(GvHD)in NSG mice.These data suggest that we have provided a feasible approach to the generation of“off-theshelf”anti-HIV CAR-T cells in combination with PD-1 checkpoint blockade immunotherapy,which can be a powerful therapeutic candidate for the functional cure of HIV.
基金supported by the National Natural Science Foundation of China(Grant No.61176043)the Special Funds for Provincial Strategic and Emerging Industries Projects of Guangdong Province,China(Grant Nos.2010A081002005,2011A081301003,and 2012A080304016)the Youth Foundation of South China Normal University(Grant No.2012KJ018)
文摘Blue InGaN light-emitting diodes （LEDs） with a conventional electron blocking layer （EBL）, a common n-A1GaN hole blocking layer （HBL）, and an n-A1GaN HBL with gradual A1 composition are investigated numerically, which involves analyses of the carrier concentration in the active region, energy band diagram, electrostatic field, and internal quantum efficiency （IQE）. The results indicate that LEDs with an n-AIGaN HBL with gradual AI composition exhibit better hole injection efficiency, lower electron leakage, and a smaller electrostatic field in the active region than LEDs with a conven tional p-A1GaN EBL or a common n-A1GaN HBL. Meanwhile, the efficiency droop is alleviated when an n-A1GaN HBL with gradual A1 composition is used.
基金supported by the National Natural Science Foundation of Beijing, China (No.7212027 & No.7214223)National Key Research and Development Program of China (2017YFC0908800)the Beijing Municipal Health Commission (PXM2020_026272_000002 & PXM2020_026272_000014)。
文摘BACKGROUND M1 polarization of macrophages is an important pathological process in myocardial ischemia reperfusion injury, which is the major obstacle for the treatment of acute myocardial infarction. Currently, the strategies and mechanisms of inhibiting M1 polarization are poorly explored. This study aims to investigate the role of soluble death receptor 5-Fc(s DR5-Fc) in regulating M1 polarization of macrophages under extreme conditions and explore the mechanisms from the aspect of glycolysis.METHODS Extreme conditions were induced in RAW264.7 cells. Real-time quantitative polymerase chain reaction and western blot were used to detect the expression of m RNA and proteins, respectively. Cell counting kit-8 was used to investigate the proliferation activity of cells. Expression levels of inflammatory cytokines were determined by enzyme-linked immunosorbent assay.RESULTS We found that s DR5-Fc rescues the proliferation of macrophages under extreme conditions, including nutrition deficiency, excessive peroxide, and ultraviolet irradiation. In addition, administration of s DR5-Fc inhibits the M1 polarization of macrophages induced by lipopolysaccharide(LPS) and interferon-gamma(IFN-γ), as the expression of M1 polarization markers CD86, CXC motif chemokine ligand 10, matrix metalloproteinase 9, and tumor necrosis factor-α, as well as the secretion of inflammatory factors interleukin(IL)-1β and IL-6, were significantly decreased. By further investigation of the mechanisms, the results showed that s DR5-Fc can recover the LPS and IFN-γ induced p H reduction, lactic acid elevation, and increased expression of hexokinase 2 and glucose transporter 1, which were markers of glycolysis in macrophages.CONCLUSIONS s DR5-Fc inhibits the M1 polarization of macrophages by blocking the glycolysis, which provides a new direction for the development of strategies in the treatment of myocardial ischemia reperfusion injury.
基金funded by the National Natural Science Foundation of China(No.51974343)the Open Fund of Hubei Key Laboratory of Drilling and Production Engineering for Oil and Gas(Yangtze University)(No.YQZC202307)+2 种基金the Qingdao Postdoctoral Applied Research Project(No.qdyy20200084)the China Postdoctoral Science Foundation(No.2021M703588)a project of Science&Technology R&D Department of SINOPEC entitled Key Technology for Optimization Design of 3D Development of Shale oil in Dongying Sag(No.P23026).
文摘Currently,limited studies of immiscible water-alternating-CO_(2)(imWACO_(2))flooding focus on the impact of reservoir heterogeneity on reservoir development outcomes.Given this,using the heterogeneous reservoirs in the Gao 89-1 block as a case study,this study conducted slab core flooding experiments and numerical simulations to assess the impact of reservoir heterogeneity on imWACO_(2)flooding efficiency.It can be concluded that imWACO_(2)flooding can enhance the sweep volume and oil recovery compared to continuous CO_(2)flooding.As the permeability difference increases,the difference in the swept volume between zones/layers with relatively high and low permeability increases.To optimize the exploitation of reservoirs in the Gao 89-1 block,the optimal timing and CO_(2)injection rate for imWACO_(2)flooding are determined at water cut of 40%and 10000 m^(3)/d,respectively.A short injection-production semi-period,combined with multiple cycles of water and CO_(2)injection alternations,is beneficial for enhanced oil recovery from imWACO_(2)flooding.
基金supported by the National Key R&D Program of China(2023YFA1801200)the National Natural Science Foundation of China(22171178 and22071143)+1 种基金The Sailing Programof Science&Technology Commission of Shanghai Municipality(22YF1413200)the Opening Project of Guangdong Provincial Key Laboratory of Quality&Safety Risk Assessment for Agro-products(SZKF202404)are also appreciated。
文摘The efficient construction of valuable N-heterocycles is one of the most important tasks in organic synthesis.Pyrrolo[2,3-b]indoles represent a privileged skeleton,which are extensively found in natural products,pharmaceuticals and luminescent materials.Nevertheless,their synthesis suffers from pre-functionalized starting materials and multi-step synthesis.On the other hand,despite significant progress in isocyanide insertions.
基金support from the Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang(2022R01007)the NSFC(22301280),and the Start-up Research Grant from Zhejiang Normal University.
文摘We developed a novel Pd-catalyzed carbonylation of ortho-alkenyl iodobenzenes with co,affording a diverse array of 3-arylindenones in good to excellent yields(up to 94%yield).This methodology exhibits broad substrate scope and good functional group compatibility.The synthetic utility was demonstrated by a gram-scale reaction,diverse product derivatizations,and the preparation of an intermediateforaPPARyagonist.
基金supported by the National Natural Science Foundation of China(22271024,21632005)the Natural Science Foundation of Jiangsu Province(BK20190929)Changzhou University.
文摘This work describes an effective Pd-catalyzed isomerization-hydroformylation of internal olefins with HCO_(2)H and N-formylsaccharin,providing a wide variety of linear aldehydes in up to 72%yield with up to 18:1 l/b ratio.The olefin substrate can bear various functional groups.Conjugated olefins can also be efficiently isomerized and hydroformylated.The reaction is easy to operate and requires no handling of CO and H_(2).To the best of our knowledge,the current process represents the first example for Pd-catalyzed efficient isomerization-hydroformylation process of internal olefins to predominately give linear aldehydes.
基金the National Natural Science Foundation of China(Nos.22271160,22471132,and 22171140)the campus Projects of Handan University(No.Xz2023014)for financial support.
文摘Comprehensive Summary.The use of CO_(2) as a renewable C1 source for the synthesis of value-added chemicals can contribute to a more sustainable chemistry.In this work,a nickel-catalyzed amide-directed carboxylation of aryl C−F bonds with CO_(2) has been developed.The reaction is switchable controlled by LiCl to react with one or two molecules of CO_(2) to afford valuable phthalimides orα-hydroxycarboxylic acid derivatives.Further study shows that the reaction is a step-by-step process.The first step is a nickel-catalyzed carboxylation of aryl C−F bonds with CO_(2) and tandem cyclization to afford phthalimides.The second step is a nickel-catalyzed C−N bond carboxylation of phthalimides with CO_(2),and intramolecular nucleophilic addition of amide anion to the carbonyl.The carboxylation of phthalimides with CO_(2) is also developed based on this reaction.The work features inert C−F bond functionalization,amide C−N bond activation,and multiple CO_(2) incorporation.Mechanistic studies indicate that the azanickelacycle intermediates play an important role,and LiCl facilitates the reduction of Ni(II)to Ni(I)and promotes the carboxylation with the second molecule of CO_(2).This protocol provides an efficient route for C−F bond functionalization under mild conditions via the chemical fixation of one or two molecules of CO_(2).
基金financial support from the the National Natural Science Foundation of China(Grants 21971080,21971079,21772051)supported by 111 Project B17019.
文摘This review provides a comprehensive summary of progress to date in the utilization of rongalite as a versatile reagent in organic synthesis,with a focus on recent researches.The contents have been organized according to the functions exhibited by rongalite.Reaction mechanisms are provided,demonstrating the multifaceted roles of this compound in various transformations,including as a sulfone,C1 or masked proton source and as a single electron donor or reducing agent.
基金the National Key R&D Program of China(2022YFF0709802)the National Natural Science Foundation of China(22271205)PAPD is gratefully acknowledged.
文摘Eight zwitterionic rare earth metal complexes stabilized by amino-bridged tris(phenolato)ligands bearing quaternary ammonium side-arms were synthesized and characterized.These complexes were used as single-component catalysts for the cycloaddition of CO_(2)and epoxides,and their catalytic activities are obviously higher than those of their binary analogues.Further studies revealed that the halide anions(Cl^(–),Br^(–),I^(–))and the metal complexes influenced the catalytic activity,and the lanthanum complex bearing iodide anion showed the highest catalytic activity for this addition reaction.A variety of mono-substituted epoxides were converted to cyclic carbonates in good to excellent yields(55%—99%)with high selectivity(>99%)at 30℃and 1 bar CO_(2),whereas internal epoxides required higher both reaction temperatures(60—120℃)and catalyst loading(2 mol%)for high yields.The catalyst was recyclable for four times without noticeable loss of catalytic activity.Based on the results of kinetic studies and in℃situ IR reactions,a plausible reaction mechanism was proposed.
基金supported by C1 Gas Refinery Program(2018M3D3A1A01018006)Direct Air Capture and Utilization(DACU)grant(RS-2023-00259920)through the National Research Foundation of Korea funded by the Ministry of Science,ICTFuture Planning,Republic of Korea.
文摘Poly(3-hydroxyalkanoates) (PHAs) are a promising class of biodegradable polymers,exhibiting properties comparable to traditional petroleum-based counterparts.Nonetheless,the widespread commercialization of PHAs is hindered by the absence of an efficient and economically viable catalytic system,impeding their competitiveness against non-biodegradable polymers.In an effort to address this challenge,we present a study on a newly developed chloro-bridged dimeric salphen zirconium cobaltate complex for the direct synthesis of PHAs via carbonylative polymerization of epoxides.The catalytic system demonstrates favorable activity under mild reaction conditions,enabling complete monomer conversion and an impressive 92% selectivity towards PHA formation.Through meticulous control experiments and mechanistic studies,we have gained crucial insights into the polymerization process.Remarkably,our findings challenge the prevailing notion of sequential ring-opening polymerization of in-situ generated β-lactones as the primary pathway.Instead,we demonstrate that the polymerization predominantly proceeds through direct co-polymerization of epoxide and carbon monoxide,unveiling a unique and efficient mechanism for PHA synthesis.
基金the financial support from the National Natural Science Foundation of China(No.21503161)the Key Research&Development Project in Shaanxi Province(No.2017ZDXM-GY-040)the Doctoral Scientific Research Foundation of Xi'an Polytechnic University(No.107020336).
文摘We reported for the first time that ethyl bromodifluoroacetate directly reacts with azaindole without transition metal catalysis to produce a difluoromethyl protected 5-aldehyde group product in one step.It is worth mentioning that the reacted aldehyde group is only formed at the 5 position.In addition,this method has good substrate applicability and functional group tolerance.Finally,we also carried out some mechanism auxiliary experiments,which confirmed that the aldehyde-based carbon comes from ethyl bromodifluoroacetate.
基金from the equipment and framework of the COMP-HUB Initiative,funded by the“Departments of Excellence"program of the Italian Ministry for Education,University and Research(MIUR,2018-2022)"ECOSISTER"funded under the National Recovery and Resilience Plan(NRRP),Mission 04 Component 2 Investment 1.5-NextGenerationEU(Call for tender n.3277,30/12/2021Award Number 0001052,dated 23/06/2022).
文摘A highly selective palladium-catalyzed carbonylation of 2-alkynylanilines bearing an amide moiety to condensed six-membered heterocyclic structures has been developed under mild conditions(room temperature and atmospheric pressure of CO).The carbonylative protocol is also compatible with CO surrogates,such as benzene-1,3,5-triyl triformate(TFBen)or the newly developed calix[6]arenes functionalized with six formate groups(CLX[6]CO),which are both capable to release CO in situ.A series of tricyclic fused heterocycles containing the important oxazino-quinolinone scaffold have been selectively obtained(only the 6-endo-dig cyclization mode has been observed)in good to excellent yields(up to 99%).
基金financial support from the National Natural Science Foundation of China(22101005)the National Key Research and Development Program of China(2021YFD1700104)+1 种基金Key R&D Projects of Anhui Province(202104a06020008)Excellent Youth Program of Anhui Province(2022AH030095).
文摘A deuterated methylthiolating reagent with a broad spectrum,designated as DMTp,has been ingeniously formulated.This new reagent can be produced with high efficiency through the simple combination of commercially available methyl 3-thiopropanoate and CD_(3)l.This novel SCD_(3) reagent exhibits excellent reactivity with electrophiles such as alkyl iodides,benzyl chlorides,aryl halides(l,Br)and aryl triflates,resulting in high levels of deuterium content(99%D).Representative deuterated methylthiolated biomolecules,such as Sulfoxaflor,havebeen synthesizedforuse in pharmaceutical discoveryand development.
