Palladium-catalyzed carboxylative Suzuki coupling reactions of benzyl chlorides with allyl pinacol-borate were successfully conducted in the absence of any extra ligand to produce β,γ-unsaturated esters in satisfact...Palladium-catalyzed carboxylative Suzuki coupling reactions of benzyl chlorides with allyl pinacol-borate were successfully conducted in the absence of any extra ligand to produce β,γ-unsaturated esters in satisfactory to good yields. The carboxylative Suzuki coupling reaction proceeded smooth-ly under mild conditions in the presence of palladium nanoparticles generated in situ through the formation of a π-benzylpalladium chloride intermediate.展开更多
A novel bromination of α,β-unsaturated carboxylic acids was developed via a decarboxylation by virtue of a direct anodic electro-oxidation.In this method,ammonium bromide was employed as a bromine source and the rea...A novel bromination of α,β-unsaturated carboxylic acids was developed via a decarboxylation by virtue of a direct anodic electro-oxidation.In this method,ammonium bromide was employed as a bromine source and the reaction features transition-metal-free,short time,and no additional supporting electrolyte.展开更多
The development of new catalytic methodologies to synthesize heterocyclic fine chemicals using carbon dioxide as a synthon has attracted considerable attention. Herein, we report the silver( I)-catalyzed carboxylative...The development of new catalytic methodologies to synthesize heterocyclic fine chemicals using carbon dioxide as a synthon has attracted considerable attention. Herein, we report the silver( I)-catalyzed carboxylative cyclization of a variety of alkynic hydrazones with carbon dioxide to produce the corresponding 1,3,4-oxadiazin-2-ones under mild reaction conditions. In this reaction, silver(I) salts play a π-Lewis acid role for the highly efficient activation of the alkyne moiety in the hydrazone substrates. Single-crystal X-ray analysis and NOE experiments confirm that the newly formed oxadiazinone products exhibit Z configuration. Based on control experiments and NMR studies, a mechanism including the formation of a reactive carbazate intermediate, electrophilic cyclization, and subsequent protonation is proposed. This study offers an efficient and atom- economical method for the synthesis of biologically important 1,3,4-oxadiazin-2-ones.展开更多
A novel and general carbon-nitrogen and carbon-carbon cross-coupling reaction between 3,4-dihydropyrimidine-2-thiones and copper（Ⅰ） carboxylates were performed in the presence of palladium acetate.The copper（Ⅰ） ...A novel and general carbon-nitrogen and carbon-carbon cross-coupling reaction between 3,4-dihydropyrimidine-2-thiones and copper（Ⅰ） carboxylates were performed in the presence of palladium acetate.The copper（Ⅰ） carboxylates act not only as desulfurative reagents but also as sources of carbon nudeophiles.A wide array of highly substituted and functionalized pyrimidines scaffolds were synthesized in good yields.展开更多
Silver-catalyzed decarboxylative C–H alkylation of cyclic aldimines with abundant aliphatic carboxylic acids has been realized under mild reaction conditions generating the corresponding products in moderate to good ...Silver-catalyzed decarboxylative C–H alkylation of cyclic aldimines with abundant aliphatic carboxylic acids has been realized under mild reaction conditions generating the corresponding products in moderate to good yields(32%–91%).In addition,a gram-scale reaction,late-stage modification of drug,synthetic transformation of the product,and further application of the catalytic strategy were also performed.Preliminary studies indicate that the reaction undergoes a radical process.展开更多
We report a tandem asymmetric Cu-catalyzed propargylic amination(ACPA)/Ag-catalyzed carboxylative cyclization(SCC)with CO_(2) to 5-methylidene-2-oxazolidinones;even with tetrasubstituted stereocenters.By varying pyrid...We report a tandem asymmetric Cu-catalyzed propargylic amination(ACPA)/Ag-catalyzed carboxylative cyclization(SCC)with CO_(2) to 5-methylidene-2-oxazolidinones;even with tetrasubstituted stereocenters.By varying pyridine bisoxazoline(PYBOX)ligands;a general and highly enantioselective ACPA of unprecedentedly broad scope of secondary propargylic acetates and primary amines is achieved.Bothα-aryl andα-aliphatic propargylic acetates could react with either aromatic or aliphatic primary amines to give the corresponding N-aryl or N-aliphatic ethynylamines withα-aliphatic orα-aryl groups in over 90%ee for use in the next step.The key to developing this one-pot sequence is to use a chelator triethylenetetramine(TETA)to mask the copper ion;to avoid its negative effect on Ag-catalyzed cyclization;whilst releasing PYBOX to activate the silver catalyst.With the methylidene moiety;these oxazolidinones can be readily elaborated.The value of the sequence is further shown by the catalytic enantioselective total synthesis of(–)-cytoxazone and the potent ezetimibe analogue.展开更多
The direct construction of C(sp^(3))−C(sp^(2))bonds from operationally convenient,synthetically versatile,and readily accessible building blocks serves as a key driving force for innovation in synthetic organic chemis...The direct construction of C(sp^(3))−C(sp^(2))bonds from operationally convenient,synthetically versatile,and readily accessible building blocks serves as a key driving force for innovation in synthetic organic chemistry.These scaffolds enhance drug properties,facilitating the development and clinical translation of lead compounds.In this work,we report the first use of the synergistic effect between Co and Ce LMCT catalysis,presenting an effective photocatalytic strategy for the decarboxylative Heck type coupling reaction of primary,secondary,and tertiary aliphatic carboxylic acids.Under mild conditions,this method achieves the effective coupling of C(sp^(3))and C(sp^(2))motifs,demonstrating excellent functional group tolerance and offering significant potential for the late-stage modification of bioactive carboxylic acids.Notably,this transformation proceeds without the need for external oxidants or pre functionalization of the carboxylic acids,with H_(2)and CO_(2)as the sole byproducts.展开更多
Alkylamines play an important role in medicinal chemistry,while carboxylic acids are commonly found in many natural products and pharmaceuticals.In this study,we developed a direct photoredox-catalyzed decarboxylative...Alkylamines play an important role in medicinal chemistry,while carboxylic acids are commonly found in many natural products and pharmaceuticals.In this study,we developed a direct photoredox-catalyzed decarboxylative amination of alkyl carboxylic acids using a novel N-centered radical scavenger.This method avoids pre-activation and transition-metal catalysts,allowing a diverse range of readily available carboxylic acids to be efficiently converted into medicinally valuable amines.Further mechanistic studies and DFT calculations were conducted to provide evidence for the proposed photoredox-catalyzed pathway.This protocol is operationally simple and has excellent functional group compatibility,which is likely to be of great use in synthetic chemistry.展开更多
A carboxylative coupling reaction of various primary amine and 3-phenyl-2-propynyl or 2-nonynyl chloride in the presence of 8-diazabicyclo[5.4.0]undec-7-ene(DBU)using carbon dioxide as carboxylative reagent was presen...A carboxylative coupling reaction of various primary amine and 3-phenyl-2-propynyl or 2-nonynyl chloride in the presence of 8-diazabicyclo[5.4.0]undec-7-ene(DBU)using carbon dioxide as carboxylative reagent was presented.This transition-metal free reaction system shows broad substrate scope and gives a series of propargylcarbamates in moderate to good yield.The obtained N-alkyl substituted carbamate product can undergo base-catalyzed intramolecular cyclization reaction to afford functionalized 4-methylene-2-oxazolidinone in good yield.展开更多
A copper-catalyzed decarboxylative oxidative coupling of α,β-unsaturated carboxylic acids with non-cyclic ethers is developed.This method provides a new approach for C(sp^3)–H bond functionalization of non-cyclic e...A copper-catalyzed decarboxylative oxidative coupling of α,β-unsaturated carboxylic acids with non-cyclic ethers is developed.This method provides a new approach for C(sp^3)–H bond functionalization of non-cyclic ethers. Mechanism study shows the reaction involves a radical process.展开更多
Ketones serve as one of the most critical building blocks in organic synthesis,involving numerous functional group transformations.Herein,we rep ort an unprecedented photoredox-nickel metallap hotoredox-catalyzed deca...Ketones serve as one of the most critical building blocks in organic synthesis,involving numerous functional group transformations.Herein,we rep ort an unprecedented photoredox-nickel metallap hotoredox-catalyzed decarboxylative acylation of common aliphatic acids with readily available aromatic and aliphatic thioesters.A wide range of structurally diverse asymmetrical aryl alkyl and dialkyl ketones have been constructed in yields of up to 98% with this strategy.The protocol has excellent reaction selectivity and functional group compatibility,representing a significant step forward in ketone synthesis.The one-pot decarboxylative acylation at the gram scale from two different carboxylic acids and the late-stage application for the synthesis of complex ketones shows its synthetic robustness.Both mechanistic experiments and density functional theory(DFT)calculations suggest that the decarboxylative acylation reaction operates via an underdeveloped Ni(Ⅰ)-Ni(Ⅱ)-Ni(Ⅰ)-Ni(Ⅲ)-Ni(Ⅰ)catalytic cycle.展开更多
Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully construct...Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully constructed by coordinatively assembling the semi-rigid multidentate ligand 5-(1-carboxyethoxy)isophthalic acid(H₃CIA)with the Nheterocyclic ligands 1,4-di(4H-1,2,4-triazol-4-yl)benzene(1,4-dtb)and 1,4-di(1H-imidazol-1-yl)benzene(1,4-dib),respectively,around Co^(2+)ions.Single-crystal X-ray diffraction analysis revealed that in both complexes HU23 and HU24,the CIA^(3-)anions adopt aκ^(7)-coordination mode,bridging six Co^(2+)ions via their five carboxylate oxygen atoms and one ether oxygen atom.This linkage forms tetranuclear[Co4(μ3-OH)2]^(6+)units.These Co-oxo cluster units were interconnected by CIA^(3-)anions to assemble into 2D kgd-type structures featuring a 3,6-connected topology.The 2D layers were further connected by 1,4-dtb and 1,4-dib,resulting in 3D pillar-layered frameworks for HU23 and HU24.Notably,despite the similar configurations of 1,4-dtb and 1,4-dib,differences in their coordination spatial orientations lead to topological divergence in the 3D frameworks of HU23 and HU24.Topological analysis indicates that the frameworks of HU23 and HU24 can be simplified into a 3,10-connected net(point symbol:(4^(10).6^(3).8^(2))(4^(3))_(2))and a 3,8-connected tfz-d net(point symbol:(4^(3))_(2)((4^(6).6^(18).8^(4)))),respectively.This structural differentiation confirms the precise regulatory role of ligands on the topology of metal-organic frameworks.Moreover,the ultraviolet-visible absorption spectra confirmed that HU23 and HU24 have strong absorption capabilities for ultraviolet and visible light.According to the Kubelka-Munk method,their bandwidths were 2.15 and 2.08 eV,respectively,which are consistent with those of typical semiconductor materials.Variable-temperature magnetic susceptibility measurements(2-300 K)revealed significant antiferromagnetic coupling in both complexes,with their effective magnetic moments decreasing markedly as the temperature lowered.CCDC:2457554,HU23;2457553,HU24.展开更多
In this study,polyacrylic acid(PAA)films were employed as a model system,and a series of PAA films with tunable water wettability was systematically prepared by varying molecular weight and curing temperature.Using at...In this study,polyacrylic acid(PAA)films were employed as a model system,and a series of PAA films with tunable water wettability was systematically prepared by varying molecular weight and curing temperature.Using attenuated total reflectance Fourier-transform infrared spectroscopy(ATR-FTIR),the molecular configurations of surface carboxyl groups(COOH),free carboxyl(COOH_(f))and hydrogen-bonded carboxyl(COOH_(HB),were directly correlated with the polar component of surface energy(γ^(s,p)).By decomposing theγ^(s,p)values of the PAA thin films as a sum of the contributions of COOH_(f)and COOH_(H B),the intrinsic polar component of surface energy of COOH_(H B)(γ_(H B)^(s,p*))was quantified for the first time as 8.34 mN/m,significantly lower than that of COOH_(f)(γ_(f)^(s,p*)=34 mN/m).This result highlights that hydrogen bonding markedly reduces theγ^(s,p),providing a rational explanation for the relatively large water contact angle observed on PAA thin films.Furthermore,it establishes a thermodynamic basis for estimating the fraction of surface COOH_(H B)groups(f H B)from wettability measurements.Further extension of the model to carboxyl-terminated self-assembled monolayers(COOH-SAMs)revealed that surface COOH density(ΣCOOH)critically regulates wetting behavior:whenΣCOOH ranges from 4.30 to 5.25 nm^(-2),COOH groups predominantly exist in a free state and facilitate effective hydration layers,thereby promoting superhydrophilicity.Overall,this study not only establishes a unified thermodynamic framework linking surface COOH configurations to macroscopic wettability,but also validates its universality by extending it to COOH-SAMs systems,thereby providing a unified theoretical framework for the controllable design of hydrophilicity in various COOH-functionalized surfaces.展开更多
A visible-light-induced synergistic hydrogen atom transfer(HAT)and proton transfer(PT)catalysis was developed for the defluorinative carboxylation of α-CF_(2)R-substituted alkenes.This system affords a variety of γ,...A visible-light-induced synergistic hydrogen atom transfer(HAT)and proton transfer(PT)catalysis was developed for the defluorinative carboxylation of α-CF_(2)R-substituted alkenes.This system affords a variety of γ,γ-difluoro-and γ-monofluoro-vinylacetic acids without stepwise acidification,exhibiting good functional group tolerance,broad scope,and facile scalability.Mechanism studies support that thiol plays the role of the hydrogen relay,which s a hydrogen atom through HAT and then outputs a proton via PT.This strategy also takes full advantage of formate for photocatalytic carboxylation reaction in a step-and atomeconomical way.展开更多
In this study,electrochemical C-H carboxylation of benzylamines with CO_(2) was reported.This linear paired electrolysis system enables efficient and economical synthesis of value-added α-amino acids(α-AAs) under mi...In this study,electrochemical C-H carboxylation of benzylamines with CO_(2) was reported.This linear paired electrolysis system enables efficient and economical synthesis of value-added α-amino acids(α-AAs) under mild conditions.Various substituted benzylamines containing diverse functional groups and even highly reactive moieties,such as cyano,amide and alkene groups could be successfully transformed to the carboxylated products.Notably,this method proved to be applicable to the late-stage modification of biorelevant compounds,highlighting its potential for synthetic chemistry.Mechanistic studies such as radical trapping experiments,kinetic isotope effect(KIE) tests and cyclic voltammetry(CV) studies provided useful insight into this transformation.展开更多
Zn-I_(2) batteries have emerged as promising next-generation energy storage systems owing to their inherent safety,environmental compatibility,rapid reaction kinetics,and small voltage hysteresis.Nevertheless,two crit...Zn-I_(2) batteries have emerged as promising next-generation energy storage systems owing to their inherent safety,environmental compatibility,rapid reaction kinetics,and small voltage hysteresis.Nevertheless,two critical challenges,i.e.,zinc dendrite growth and polyiodide shuttle effect,severely impede their commercial viability.To conquer these limitations,this study develops a multifunctional separator fabricated from straw-derived carboxylated nanocellulose,with its negative charge density further reinforced by anionic polyacrylamide incorporation.This modification simultaneously improves the separator’s mechanical properties,ionic conductivity,and Zn^(2+)ion transfer number.Remarkably,despite its ultrathin 20μm profile,the engineered separator demonstrates exceptional dendrite suppression and parasitic reaction inhibition,enabling Zn//Zn symmetric cells to achieve impressive cycle life(>1800 h at 2 m A cm^(-2)/2 m Ah cm^(-2))while maintaining robust performance even at ultrahigh areal capacities(25 m Ah cm^(-2)).Additionally,the separator’s anionic characteristic effectively blocks polyiodide migration through electrostatic repulsion,yielding Zn-I_(2) batteries with outstanding rate capability(120.7 m Ah g^(-1)at 5 A g^(-1))and excellent cyclability(94.2%capacity retention after 10,000 cycles).And superior cycling stability can still be achieved under zinc-deficient condition and pouch cell configuration.This work establishes a new paradigm for designing high-performance zinc-based energy storage systems through rational separator engineering.展开更多
A novel decarboxylative fluorination process has been developed for the synthesis of ortho-hydroxy/amino arylfluorides from salicylic acid analogs, in which the ortho-hydroxy/amino group plays an important role in the...A novel decarboxylative fluorination process has been developed for the synthesis of ortho-hydroxy/amino arylfluorides from salicylic acid analogs, in which the ortho-hydroxy/amino group plays an important role in the transformation. In addition, various arylfluorides are obtained in good to excellent yields under mild conditions.展开更多
An efficient decarboxylative/defluorinative alkylation for synthesizing gem-difluoroalkenes is described,providing a general method for installation of the challenging alkyl fragments containing a-electron-withdrawing...An efficient decarboxylative/defluorinative alkylation for synthesizing gem-difluoroalkenes is described,providing a general method for installation of the challenging alkyl fragments containing a-electron-withdrawing groups into a-trifluoromethyl alkenes.Mechanistic studies suggest that this process involves an SN2,-type synthetic route in the absence of transition-metal catalysts or photocatalysis.Moreover,this protocol can easily be scaled up,and successfully applied to the modification of biologically active molecules,thus complementing methodologies that give access to structurally versatile gem-difluoroalkenes.展开更多
A direct oxidative radical decarboxylative cyanomethylation of carboxylic acids is described using 3-azido-2-methylbut-3-en-2-ol as the carbon-centered radical acceptor.The transformation is applicable to structurally...A direct oxidative radical decarboxylative cyanomethylation of carboxylic acids is described using 3-azido-2-methylbut-3-en-2-ol as the carbon-centered radical acceptor.The transformation is applicable to structurally diverseα-amino acids,α-oxy acids,α-keto ac-ids,pentofuranuronic acids,and hexopyranuronic acids.The mechanistic investigations suggest that a radical process is involved in the transformation.This work provides a potential approach toβ-amino acid,5-deoxy-hexofuranose,and 6-deoxy-heptose con-structs of biological relevance.展开更多
In this paper,we have developed a decarboxylative amination of carboxylic acids with nitroarenes for the synthesis of secondary amines.The protocol is performed at mild conditions without the use of noble metals as ca...In this paper,we have developed a decarboxylative amination of carboxylic acids with nitroarenes for the synthesis of secondary amines.The protocol is performed at mild conditions without the use of noble metals as catalysts.A wide range of structurally diverse secondary amines could be obtained in good yields(up to 94%)with good functional group tolerance.This transformation shows good to excellent selectivity,avoiding the generation of over alkylated byproducts.展开更多
文摘Palladium-catalyzed carboxylative Suzuki coupling reactions of benzyl chlorides with allyl pinacol-borate were successfully conducted in the absence of any extra ligand to produce β,γ-unsaturated esters in satisfactory to good yields. The carboxylative Suzuki coupling reaction proceeded smooth-ly under mild conditions in the presence of palladium nanoparticles generated in situ through the formation of a π-benzylpalladium chloride intermediate.
基金the National Nature Science Foundation of China(Nos.21472177,21672200,21432009,J1310010)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB20000000)
文摘A novel bromination of α,β-unsaturated carboxylic acids was developed via a decarboxylation by virtue of a direct anodic electro-oxidation.In this method,ammonium bromide was employed as a bromine source and the reaction features transition-metal-free,short time,and no additional supporting electrolyte.
基金supported by the National Natural Science Foundation of China(21878038)the Natural Science Foundation of Liaoning Province(20170540156)the Program for Changjiang Scholars and Innovative Research Team in University(IRT-17R14)~~
文摘The development of new catalytic methodologies to synthesize heterocyclic fine chemicals using carbon dioxide as a synthon has attracted considerable attention. Herein, we report the silver( I)-catalyzed carboxylative cyclization of a variety of alkynic hydrazones with carbon dioxide to produce the corresponding 1,3,4-oxadiazin-2-ones under mild reaction conditions. In this reaction, silver(I) salts play a π-Lewis acid role for the highly efficient activation of the alkyne moiety in the hydrazone substrates. Single-crystal X-ray analysis and NOE experiments confirm that the newly formed oxadiazinone products exhibit Z configuration. Based on control experiments and NMR studies, a mechanism including the formation of a reactive carbazate intermediate, electrophilic cyclization, and subsequent protonation is proposed. This study offers an efficient and atom- economical method for the synthesis of biologically important 1,3,4-oxadiazin-2-ones.
基金Financial support from the National Natural Science Foundation of China(Nos.21362032 and 21362031)the NSF of Gansu Province(No.1208RJYA083)
文摘A novel and general carbon-nitrogen and carbon-carbon cross-coupling reaction between 3,4-dihydropyrimidine-2-thiones and copper（Ⅰ） carboxylates were performed in the presence of palladium acetate.The copper（Ⅰ） carboxylates act not only as desulfurative reagents but also as sources of carbon nudeophiles.A wide array of highly substituted and functionalized pyrimidines scaffolds were synthesized in good yields.
基金financially supported by the National Natural Science Foundation of China(Nos.21402116,21502111,21572126)the Science and Technology Innovation Talents of Henan Province(No.2018JQ0011)the Key Science Research of Education Committee in Henan Province(No.21A150044)。
文摘Silver-catalyzed decarboxylative C–H alkylation of cyclic aldimines with abundant aliphatic carboxylic acids has been realized under mild reaction conditions generating the corresponding products in moderate to good yields(32%–91%).In addition,a gram-scale reaction,late-stage modification of drug,synthetic transformation of the product,and further application of the catalytic strategy were also performed.Preliminary studies indicate that the reaction undergoes a radical process.
基金supported by the National Natural Science Foundation of China(21871090,21725203)the National Key Research and Development Program of China(2020YFA0710200)+2 种基金the Shanghai Science and Technology Innovation Action Plan(20JC1416900)the Innovation Program of Shanghai Municipal Education Commission(2023ZKZD37)the Fundamental Research Funds for the Central Universities.
文摘We report a tandem asymmetric Cu-catalyzed propargylic amination(ACPA)/Ag-catalyzed carboxylative cyclization(SCC)with CO_(2) to 5-methylidene-2-oxazolidinones;even with tetrasubstituted stereocenters.By varying pyridine bisoxazoline(PYBOX)ligands;a general and highly enantioselective ACPA of unprecedentedly broad scope of secondary propargylic acetates and primary amines is achieved.Bothα-aryl andα-aliphatic propargylic acetates could react with either aromatic or aliphatic primary amines to give the corresponding N-aryl or N-aliphatic ethynylamines withα-aliphatic orα-aryl groups in over 90%ee for use in the next step.The key to developing this one-pot sequence is to use a chelator triethylenetetramine(TETA)to mask the copper ion;to avoid its negative effect on Ag-catalyzed cyclization;whilst releasing PYBOX to activate the silver catalyst.With the methylidene moiety;these oxazolidinones can be readily elaborated.The value of the sequence is further shown by the catalytic enantioselective total synthesis of(–)-cytoxazone and the potent ezetimibe analogue.
基金supported by the National Natural Science Foundation of China(Grand Nos.22478356 and 22078299).
文摘The direct construction of C(sp^(3))−C(sp^(2))bonds from operationally convenient,synthetically versatile,and readily accessible building blocks serves as a key driving force for innovation in synthetic organic chemistry.These scaffolds enhance drug properties,facilitating the development and clinical translation of lead compounds.In this work,we report the first use of the synergistic effect between Co and Ce LMCT catalysis,presenting an effective photocatalytic strategy for the decarboxylative Heck type coupling reaction of primary,secondary,and tertiary aliphatic carboxylic acids.Under mild conditions,this method achieves the effective coupling of C(sp^(3))and C(sp^(2))motifs,demonstrating excellent functional group tolerance and offering significant potential for the late-stage modification of bioactive carboxylic acids.Notably,this transformation proceeds without the need for external oxidants or pre functionalization of the carboxylic acids,with H_(2)and CO_(2)as the sole byproducts.
基金financial support from National Natural Science Foundation of China(NSFC),Youth program(Grant No.22101173)Fundamental Research Funds for the Central Universities(24X010301678)"Thousand Talents Plan,Youth project"and startup funding from Shanghai Jiao Tong University(SJTU).
文摘Alkylamines play an important role in medicinal chemistry,while carboxylic acids are commonly found in many natural products and pharmaceuticals.In this study,we developed a direct photoredox-catalyzed decarboxylative amination of alkyl carboxylic acids using a novel N-centered radical scavenger.This method avoids pre-activation and transition-metal catalysts,allowing a diverse range of readily available carboxylic acids to be efficiently converted into medicinally valuable amines.Further mechanistic studies and DFT calculations were conducted to provide evidence for the proposed photoredox-catalyzed pathway.This protocol is operationally simple and has excellent functional group compatibility,which is likely to be of great use in synthetic chemistry.
基金National Natural Science Foundation of China(No.21172026)Scientific Research Fund of Liaoning Provincial Education Department(No.L2012024)X.-B.L.gratefully acknowledges the Chang Jiang Scholars Program(No.T2011056)from Ministry of Education of the People's Republic of China.
文摘A carboxylative coupling reaction of various primary amine and 3-phenyl-2-propynyl or 2-nonynyl chloride in the presence of 8-diazabicyclo[5.4.0]undec-7-ene(DBU)using carbon dioxide as carboxylative reagent was presented.This transition-metal free reaction system shows broad substrate scope and gives a series of propargylcarbamates in moderate to good yield.The obtained N-alkyl substituted carbamate product can undergo base-catalyzed intramolecular cyclization reaction to afford functionalized 4-methylene-2-oxazolidinone in good yield.
基金supported by the National Natural Science Foundation of China (21572240)
文摘A copper-catalyzed decarboxylative oxidative coupling of α,β-unsaturated carboxylic acids with non-cyclic ethers is developed.This method provides a new approach for C(sp^3)–H bond functionalization of non-cyclic ethers. Mechanism study shows the reaction involves a radical process.
基金the financial support from the National Natural Science Foundation of China(grant nos.22001117,21971108,21971111,and 21732003)the Natural Science Foundation of Jiangsu Province(grant no.BK20190006)+1 种基金Fundamental Research Funds for the Central Universities(0205/14380252),“Innovation&Entrepreneurship Talents Plan”of Jiangsu ProvinceFoundation of Advanced Catalytic Engineering Research Center of the Ministry of Education of Hunan University.
文摘Ketones serve as one of the most critical building blocks in organic synthesis,involving numerous functional group transformations.Herein,we rep ort an unprecedented photoredox-nickel metallap hotoredox-catalyzed decarboxylative acylation of common aliphatic acids with readily available aromatic and aliphatic thioesters.A wide range of structurally diverse asymmetrical aryl alkyl and dialkyl ketones have been constructed in yields of up to 98% with this strategy.The protocol has excellent reaction selectivity and functional group compatibility,representing a significant step forward in ketone synthesis.The one-pot decarboxylative acylation at the gram scale from two different carboxylic acids and the late-stage application for the synthesis of complex ketones shows its synthetic robustness.Both mechanistic experiments and density functional theory(DFT)calculations suggest that the decarboxylative acylation reaction operates via an underdeveloped Ni(Ⅰ)-Ni(Ⅱ)-Ni(Ⅰ)-Ni(Ⅲ)-Ni(Ⅰ)catalytic cycle.
文摘Under hydrothermal and solvothermal conditions,two novel cobalt-based complexes,{[Co_(2)(CIA)(OH)(1,4-dtb)]·3.2H_(2)O}n(HU23)and{[Co_(2)(CIA)(OH)(1,4-dib)]·3.5H2O·DMF}n(HU24),were successfully constructed by coordinatively assembling the semi-rigid multidentate ligand 5-(1-carboxyethoxy)isophthalic acid(H₃CIA)with the Nheterocyclic ligands 1,4-di(4H-1,2,4-triazol-4-yl)benzene(1,4-dtb)and 1,4-di(1H-imidazol-1-yl)benzene(1,4-dib),respectively,around Co^(2+)ions.Single-crystal X-ray diffraction analysis revealed that in both complexes HU23 and HU24,the CIA^(3-)anions adopt aκ^(7)-coordination mode,bridging six Co^(2+)ions via their five carboxylate oxygen atoms and one ether oxygen atom.This linkage forms tetranuclear[Co4(μ3-OH)2]^(6+)units.These Co-oxo cluster units were interconnected by CIA^(3-)anions to assemble into 2D kgd-type structures featuring a 3,6-connected topology.The 2D layers were further connected by 1,4-dtb and 1,4-dib,resulting in 3D pillar-layered frameworks for HU23 and HU24.Notably,despite the similar configurations of 1,4-dtb and 1,4-dib,differences in their coordination spatial orientations lead to topological divergence in the 3D frameworks of HU23 and HU24.Topological analysis indicates that the frameworks of HU23 and HU24 can be simplified into a 3,10-connected net(point symbol:(4^(10).6^(3).8^(2))(4^(3))_(2))and a 3,8-connected tfz-d net(point symbol:(4^(3))_(2)((4^(6).6^(18).8^(4)))),respectively.This structural differentiation confirms the precise regulatory role of ligands on the topology of metal-organic frameworks.Moreover,the ultraviolet-visible absorption spectra confirmed that HU23 and HU24 have strong absorption capabilities for ultraviolet and visible light.According to the Kubelka-Munk method,their bandwidths were 2.15 and 2.08 eV,respectively,which are consistent with those of typical semiconductor materials.Variable-temperature magnetic susceptibility measurements(2-300 K)revealed significant antiferromagnetic coupling in both complexes,with their effective magnetic moments decreasing markedly as the temperature lowered.CCDC:2457554,HU23;2457553,HU24.
文摘In this study,polyacrylic acid(PAA)films were employed as a model system,and a series of PAA films with tunable water wettability was systematically prepared by varying molecular weight and curing temperature.Using attenuated total reflectance Fourier-transform infrared spectroscopy(ATR-FTIR),the molecular configurations of surface carboxyl groups(COOH),free carboxyl(COOH_(f))and hydrogen-bonded carboxyl(COOH_(HB),were directly correlated with the polar component of surface energy(γ^(s,p)).By decomposing theγ^(s,p)values of the PAA thin films as a sum of the contributions of COOH_(f)and COOH_(H B),the intrinsic polar component of surface energy of COOH_(H B)(γ_(H B)^(s,p*))was quantified for the first time as 8.34 mN/m,significantly lower than that of COOH_(f)(γ_(f)^(s,p*)=34 mN/m).This result highlights that hydrogen bonding markedly reduces theγ^(s,p),providing a rational explanation for the relatively large water contact angle observed on PAA thin films.Furthermore,it establishes a thermodynamic basis for estimating the fraction of surface COOH_(H B)groups(f H B)from wettability measurements.Further extension of the model to carboxyl-terminated self-assembled monolayers(COOH-SAMs)revealed that surface COOH density(ΣCOOH)critically regulates wetting behavior:whenΣCOOH ranges from 4.30 to 5.25 nm^(-2),COOH groups predominantly exist in a free state and facilitate effective hydration layers,thereby promoting superhydrophilicity.Overall,this study not only establishes a unified thermodynamic framework linking surface COOH configurations to macroscopic wettability,but also validates its universality by extending it to COOH-SAMs systems,thereby providing a unified theoretical framework for the controllable design of hydrophilicity in various COOH-functionalized surfaces.
基金supported by the National Natural Science Foundation of China (22472031,U24A20567,22032002)the 111 Project。
文摘A visible-light-induced synergistic hydrogen atom transfer(HAT)and proton transfer(PT)catalysis was developed for the defluorinative carboxylation of α-CF_(2)R-substituted alkenes.This system affords a variety of γ,γ-difluoro-and γ-monofluoro-vinylacetic acids without stepwise acidification,exhibiting good functional group tolerance,broad scope,and facile scalability.Mechanism studies support that thiol plays the role of the hydrogen relay,which s a hydrogen atom through HAT and then outputs a proton via PT.This strategy also takes full advantage of formate for photocatalytic carboxylation reaction in a step-and atomeconomical way.
基金Financial support from National Key R&D Program of China (No.2023YFA1507203)National Natural Science Foundation of China (Nos.22371149 and 22188101)+3 种基金the Fundamental Research Funds for the Central Universities (No.63224098)Frontiers Science Center for New Organic Matter,Nankai University (No.63181206)Nankai University are gratefully acknowledgedthe Haihe Laboratory of Sustainable Chemical Transformations for financial support。
文摘In this study,electrochemical C-H carboxylation of benzylamines with CO_(2) was reported.This linear paired electrolysis system enables efficient and economical synthesis of value-added α-amino acids(α-AAs) under mild conditions.Various substituted benzylamines containing diverse functional groups and even highly reactive moieties,such as cyano,amide and alkene groups could be successfully transformed to the carboxylated products.Notably,this method proved to be applicable to the late-stage modification of biorelevant compounds,highlighting its potential for synthetic chemistry.Mechanistic studies such as radical trapping experiments,kinetic isotope effect(KIE) tests and cyclic voltammetry(CV) studies provided useful insight into this transformation.
基金the financial support from the Natural Science Foundation of Jiangsu Province(BK20231292)the Jiangsu Agricultural Science and Technology Innovation Fund(CX(24)3091)+6 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX25_1429)the National Key R&D Program of China(2024YFE0109200)the Fundamental Research Funds for the Central Universities(No.2024300440)Guangdong Basic and Applied Basic Research Foundation(2025A1515011098)the National Natural Science Foundation of China(12464032)the Natural Science Foundation of Jiangxi Province(20232BAB201032)Ji'an Science and Technology Plan Project(2024H-100301)。
文摘Zn-I_(2) batteries have emerged as promising next-generation energy storage systems owing to their inherent safety,environmental compatibility,rapid reaction kinetics,and small voltage hysteresis.Nevertheless,two critical challenges,i.e.,zinc dendrite growth and polyiodide shuttle effect,severely impede their commercial viability.To conquer these limitations,this study develops a multifunctional separator fabricated from straw-derived carboxylated nanocellulose,with its negative charge density further reinforced by anionic polyacrylamide incorporation.This modification simultaneously improves the separator’s mechanical properties,ionic conductivity,and Zn^(2+)ion transfer number.Remarkably,despite its ultrathin 20μm profile,the engineered separator demonstrates exceptional dendrite suppression and parasitic reaction inhibition,enabling Zn//Zn symmetric cells to achieve impressive cycle life(>1800 h at 2 m A cm^(-2)/2 m Ah cm^(-2))while maintaining robust performance even at ultrahigh areal capacities(25 m Ah cm^(-2)).Additionally,the separator’s anionic characteristic effectively blocks polyiodide migration through electrostatic repulsion,yielding Zn-I_(2) batteries with outstanding rate capability(120.7 m Ah g^(-1)at 5 A g^(-1))and excellent cyclability(94.2%capacity retention after 10,000 cycles).And superior cycling stability can still be achieved under zinc-deficient condition and pouch cell configuration.This work establishes a new paradigm for designing high-performance zinc-based energy storage systems through rational separator engineering.
基金We are grateful for the financial support from the National Natural Science Foundation of China （24172219, 21532009, 21761142010 and 21790330）, the National Basic Research Program of China （973-2015CB856600）, the strategic Priority Research Program （XDB20000000）, the Key Research Program of Froniter Science （QYZDJSSW-SLH055）, CAS, and the Science Technology Commission of the Shanghai Municipality （17XD140500 and 17JC1401200）. This research was partially supported by CAS Interdisciplinary Innovation Team.
文摘A novel decarboxylative fluorination process has been developed for the synthesis of ortho-hydroxy/amino arylfluorides from salicylic acid analogs, in which the ortho-hydroxy/amino group plays an important role in the transformation. In addition, various arylfluorides are obtained in good to excellent yields under mild conditions.
基金the support from the National Natural Science Foundation of China(Nos.21732006,51821006 and 51961135104)the Natural Science Foundation of Anhui(No.2008085MB40)+1 种基金the USTC Research Funds of the Double First Class Initiative(No.YD2060002003)The authors thank Xi Lu(University of Science and Technology of China)for insightful discussion during the preparation of the manuscript.
文摘An efficient decarboxylative/defluorinative alkylation for synthesizing gem-difluoroalkenes is described,providing a general method for installation of the challenging alkyl fragments containing a-electron-withdrawing groups into a-trifluoromethyl alkenes.Mechanistic studies suggest that this process involves an SN2,-type synthetic route in the absence of transition-metal catalysts or photocatalysis.Moreover,this protocol can easily be scaled up,and successfully applied to the modification of biologically active molecules,thus complementing methodologies that give access to structurally versatile gem-difluoroalkenes.
基金support from the National Natural Science Foundation of China(Nos.21977088,21672194)the National Natural Science Foundation of China-Shandong Joint Fund(No.U1906213)the Shandong Provincial National Natural Science Foundation(No.ZR2018MB015).
文摘A direct oxidative radical decarboxylative cyanomethylation of carboxylic acids is described using 3-azido-2-methylbut-3-en-2-ol as the carbon-centered radical acceptor.The transformation is applicable to structurally diverseα-amino acids,α-oxy acids,α-keto ac-ids,pentofuranuronic acids,and hexopyranuronic acids.The mechanistic investigations suggest that a radical process is involved in the transformation.This work provides a potential approach toβ-amino acid,5-deoxy-hexofuranose,and 6-deoxy-heptose con-structs of biological relevance.
基金National Key Research and Development Program of China(2022YFA1503200,2021YFC2101901)the National Natural Science Foundation of China(22122103,22101130,22001117,21971108,22271144)Fundamental Research Funds for the Central Universities(020514380304,020514380252,020514380272)for financial support.
文摘In this paper,we have developed a decarboxylative amination of carboxylic acids with nitroarenes for the synthesis of secondary amines.The protocol is performed at mild conditions without the use of noble metals as catalysts.A wide range of structurally diverse secondary amines could be obtained in good yields(up to 94%)with good functional group tolerance.This transformation shows good to excellent selectivity,avoiding the generation of over alkylated byproducts.
