Heterocyclic ketene aminals 1 react with aryl azides 2 to give the titled compounds 3,and in some cases also with the formation of fused heterocycles 4.
An efficient solid-phase synthesis method for novel heterocyclic ketene aminals containing a hydroxyl group has been developed. The loading of the substrate on the resin through the hydroxyl group and the protection o...An efficient solid-phase synthesis method for novel heterocyclic ketene aminals containing a hydroxyl group has been developed. The loading of the substrate on the resin through the hydroxyl group and the protection of the amine by the Schiff base were the key steps in the synthesis.展开更多
Heteroatom aroyl-substituted heterocyclic ketene aminals 1 reacted with 2,3,4,6-tetra-O-acetyl-α-glucopyranosyl bromide 2 under the catalysis of Hg(CN)2 or CaH2 to give E- or Z-O-glycosides of heterocyclic ketene am...Heteroatom aroyl-substituted heterocyclic ketene aminals 1 reacted with 2,3,4,6-tetra-O-acetyl-α-glucopyranosyl bromide 2 under the catalysis of Hg(CN)2 or CaH2 to give E- or Z-O-glycosides of heterocyclic ketene aminals 3 or 4 in moderate yields.展开更多
The anion of heterocyclic ketene aminals reacted with 2,4-dini- tro-halobenzenes to give an arylated product through the radical nucleo- philic substitution confirmed by ESR spectroscopy,ESR-spin trapping techni- que,...The anion of heterocyclic ketene aminals reacted with 2,4-dini- tro-halobenzenes to give an arylated product through the radical nucleo- philic substitution confirmed by ESR spectroscopy,ESR-spin trapping techni- que,and depression of the reaction rate by the addition of inhibitor.展开更多
Summary of main observation and conclusion A 4+2 cycloaddition reaction of NH-free benzazetidines with indoles under the catalysis of camphorsulfonic acid was developed. This method shows a broad substrate scope of be...Summary of main observation and conclusion A 4+2 cycloaddition reaction of NH-free benzazetidines with indoles under the catalysis of camphorsulfonic acid was developed. This method shows a broad substrate scope of benzazetidines and indoles, and offers a convenient method for stereoselective synthesis of various cis-2,3-fused indoline aminals. Preliminary mechanistic studies suggest the reaction proceed via a stepwise pathway featuring an electrophilic attack on the benzylic carbon of benzazetidine.展开更多
Monitoring biogenic amines,which are metabolic byproducts of shrimp spoilage,is crucial for assessing food quality.Currently,most detection methods for biogenic amines suffer from limitations such as time-consuming pr...Monitoring biogenic amines,which are metabolic byproducts of shrimp spoilage,is crucial for assessing food quality.Currently,most detection methods for biogenic amines suffer from limitations such as time-consuming procedures,complex operations,and delayed results.Colorimetric analysis techniques have gained attention in recent years due to their advantages of short analysis time,simple operation,and suitability for on-site testing.This study successfully developed a series of colorimetric sensor platforms for biogenic amines by loading the natural active ingredient curcumin(CUR)and its derivative of Boron complex BFCUR onto filter paper and electrospun nanofibre films(ENFs),respectively.By analyzing the color response differences of these sensors upon contact with biogenic amines,the colorimetric sensors with superior detection performance were selected and further applied to the visual monitoring and indication of shrimp spoilage processes.展开更多
Chiral benzylic amines are important motifs in medicines.A dicationic nickel complex of chiral diphosphine(R)-Ph-BPE promotes highly enantioselective reductive amination of aryl alkyl ketones with arylamines using iso...Chiral benzylic amines are important motifs in medicines.A dicationic nickel complex of chiral diphosphine(R)-Ph-BPE promotes highly enantioselective reductive amination of aryl alkyl ketones with arylamines using isopropanol as hydrogen source.The reaction is easily scaled up in a gram-scale synthesis using 1 mol% nickel catalyst and it is applied to an asymmetric synthesis of(S)-rivastigmine.Building on this success,we achieved rare examples of asymmetric hydrogen borrowing reactions with arylamines using an Earth-abundant 3d metal,nickel.展开更多
The widespread use of herbicides such as glyphosate isopropyl amine salt(GIS)and atrazine(ATZ)poses significant risks to aquatic ecosystems.This study investigated the single and joint acute toxicity of a 1:1 GIS-ATZ ...The widespread use of herbicides such as glyphosate isopropyl amine salt(GIS)and atrazine(ATZ)poses significant risks to aquatic ecosystems.This study investigated the single and joint acute toxicity of a 1:1 GIS-ATZ mixture on zebrafish(Danio rerio).Acute tests determined 96-h LC_(50) values of 123.41 mg/L for GIS and 103.95 mg/L for ATZ.In the joint toxicity test,these values decreased to 60.96 and 50.88 mg/L,respectively.The Additive Index(AI)analysis revealed a consistent synergistic interaction between the herbicides at all exposure intervals.These findings underscore the enhanced ecological threat of herbicide mixtures and highlight the necessity of considering joint effects in environmental risk assessments.展开更多
This study investigated the suppressive effects of Armoracia rusticana(AR)and its three main glucosinolates on both free and bound heterocyclic amines(HAs),along with their mechanisms of free radical quenching using d...This study investigated the suppressive effects of Armoracia rusticana(AR)and its three main glucosinolates on both free and bound heterocyclic amines(HAs),along with their mechanisms of free radical quenching using density functional theory.Fish patties were supplemented with varying concentrations of AR(0.5%‒1.5%)and glucosinolates(0.005%‒0.015%),showing a dose-dependent inhibition of HAs and concurrent elimination of free radicals and HAs intermediates.Glucobrassicin demonstrated the highest reactivity,which was verified by frontier orbit analysis and conceptual density functional parameters,consistent with experimental findings.Furthermore,the O-H bond connected to the sulfur atom of glucobrassicin possessed the smallest bond dissociation enthalpy(BDE)value,which indicated that this particular hydrogen atom is most susceptible to react with free radicals.Overall,AR and its glucosinolates,especially glucobrassicin,show promise as natural additives for improving food safety and quality.展开更多
A new palladium-catalyzed selective aminomethylation of conjugated 1,3-dienes with aminais via double C-N bond activation is described. This simple method provides an effective and rapid approach for the synthesis of ...A new palladium-catalyzed selective aminomethylation of conjugated 1,3-dienes with aminais via double C-N bond activation is described. This simple method provides an effective and rapid approach for the synthesis of linear a,13-unsaturated allylic amines with perfect regioselectivity. Mechanistic studies disclosed that one palladium catalyst cleaved two distinct C-N bond to furnish a cascade double C-N bond activation, in which an allylic 1,3-diamine and allylic 1,2-diamine were initially formed as key intermediates through the palladium-catalyzed C-N bond activation of aminal and the α,β-unsaturated allylic amine was subsequently produced via palladium-catalyzed C-N bond activation of the allylic diamines.展开更多
The stereoselective synthesis of O-maltosides by reacting benzoyl-substituted heterocyclic ketene aminals 1 or 2 with acetylated maltosyl bromide 3 was investigated. Compounds 1 or 2 reacted with 3 in the presence of ...The stereoselective synthesis of O-maltosides by reacting benzoyl-substituted heterocyclic ketene aminals 1 or 2 with acetylated maltosyl bromide 3 was investigated. Compounds 1 or 2 reacted with 3 in the presence of mercuric cyanide to give O-maltosides 4 or 5 with E-configuration. While 1 reacted with 3 in the presence of calcium hydride to give O-maltosides 6 with Z-configuration.展开更多
Heterogeneous metal-catalyzed chemical conversions with a recyclable catalyst are very ideal and challenging for sustainable organic synthesis.A new bipyridyl-Mo(IV)-carbon nitride(CN-K/Mo-Bpy)was prepared by supporti...Heterogeneous metal-catalyzed chemical conversions with a recyclable catalyst are very ideal and challenging for sustainable organic synthesis.A new bipyridyl-Mo(IV)-carbon nitride(CN-K/Mo-Bpy)was prepared by supporting molybdenum complex on C_(3)N_(4)-K and characterized by FT-IR,XRD,SEM,XPS and ICP-OES.Heterogeneous CN–Mo-Bpy catalyst can be applied to the direct amination of nitroarenes and arylboronic acid,thus constructing various valuable diarylamines in high to excellent yields with a wide substrate scope and good functional group tolerance.It is worth noting that this heterogeneous catalyst has high chemical stability and can be recycled for at least five times without reducing its activity.展开更多
In-depth knowledge of the microbes responsible for biogenic amine(BA)production during soy sauce fermentation remains limited.Herein,the variations in the BA profiles,microbial communities,and microbes involved in BA ...In-depth knowledge of the microbes responsible for biogenic amine(BA)production during soy sauce fermentation remains limited.Herein,the variations in the BA profiles,microbial communities,and microbes involved in BA production during the fermentation of soy sauce through Japanese-type(JP)and Cantonese-type(CP)processes were compared.BA analysis revealed that the most abundant BA species were putrescine,tyramine,and histamine in the later three stages(1187.68,785.16,and 193.20 mg/kg on average,respectively).The BA profiles differed significantly,with CP samples containing higher contents of putrescine,tyramine,and histamine(P<0.05)at the end of fermentation.Metagenomic analysis indicated that BA-producing genes exhibited different abundance profiles,with most genes,including spe A,spe B,arg,spe E,and tyr DC,having higher abundances in microbial communities during the CP process.In total,15 high-quality metagenome-assembled genomes(MAGs)were retrieved,of which 10 encoded at BA production-related genes.Enterococcus faecium(MAG10)and Weissella paramesenteroides(MAG5)might be the major tyramine producers.The high putrescine content in CP might be associated with the high abundance of Staphylococcus gallinarum(MAG8).This study provides a comprehensive understanding of the diversity and abundance of genes involved in BA synthesis,especially at the species level,during food fermentation.展开更多
Nitrogenous compounds(i.e.,amines,amides,nitriles,oximes,amino acids and nitrogen-heterocycles derivatives)are important building blocks for synthetic chemistry,pharmaceuticals,and functional materials.Conventional sy...Nitrogenous compounds(i.e.,amines,amides,nitriles,oximes,amino acids and nitrogen-heterocycles derivatives)are important building blocks for synthetic chemistry,pharmaceuticals,and functional materials.Conventional synthetic strategies involve the use of toxic organic nitrogenous precursors or expensive heterogeneous catalysts under elevated temperatures and pressurized oxygen.Heterogeneous electrocatalysis can initiate the activation of inorganic N sources(i.e.,NH_(3)and NO^(-)_(x))under ambient reactions in liquid phase by applying a small bias,thus allowing the synthesis of value?added nitrogenous compounds from carbonyls,alkenes,keto acids,and even carbon dioxide in a sustainable manner without the use of oxidants/reductants.This review outlines recent de-velopments in electrosynthesis of nitrogenous compounds using inorganic N sources,focusing on reaction mechanisms understanding,the design and optimization of efficient electrocatalysts,and the advances in cell configurations for various C‒N coupling reactions.The limitations and challenges in applications are also discussed.展开更多
Catalyst-aided regeneration is a promising method for reducing the high regeneration energy consumption of amine-based CO_(2)capture technologies.However,the intrinsic relationship between the properties of the acidic...Catalyst-aided regeneration is a promising method for reducing the high regeneration energy consumption of amine-based CO_(2)capture technologies.However,the intrinsic relationship between the properties of the acidic sites and their catalytic activity is controversial.In this study,a series of W-based catalysts supported by ZrTiO_(x)were synthesised,and the effects of the intensity,distribution,and type of acid sites were systematically investigated by quantitatively regulating the acidic site properties.The results indicate stronger acidic sites play a more important role in the catalytic reaction.Moreover,the catalysts showed excellent performance only if the Br?nsted acid sites(BASs)and Lewis acid sites(LASs)coexisted.During the catalytic reaction,the BASs facilitated deprotonation,and the LASs promoted the decomposition of carbamates.The ratio of BASs to LASs(B/L)was a critical factor for catalytic activity,wherein optimal performance was achieved when the B/L ratio was close to 1.The 10%HPW/ZrTiO_(x)composite performed better than WO_(3)/ZrTiO_(x)and HSiW/ZrTiO_(x)because it had a stronger acid intensity and a suitable B/L ratio.As a result,the relative heat duty was reduced by 47%compared to 30%aqueous MEA,and the maximum CO_(2)desorption rate was increased by 83%.The Bader charge indicated that the W atoms of HPW/ZrTiO_(x)lost more electrons(0.18)than those of WO_(3)/ZrTiO_(x),which can weaken the O±H bond energy.Consequently,the calculated deprotonation energy is as low as 257 kJ mol^(-1)for HPW/ZrTiO_(x).展开更多
Isothiocyanates(ITCs)are an important class of organic compounds characterized by the functional group R-N=C=S.These functional groups are widely found in multiple natural products and pharmaceutical important drugs.M...Isothiocyanates(ITCs)are an important class of organic compounds characterized by the functional group R-N=C=S.These functional groups are widely found in multiple natural products and pharmaceutical important drugs.Moreover,due to their high and versatile reactivity,they are widely used as an intermediate in organic synthesis.Keeping in view ITCs importance,this review summarizes their synthesis from nitrogen rich raw materials like amines,isocyanides,azides and some other compounds like oximes.Besides their synthesis,their application in organic compound synthesis as an intermediate will also be covered.Future research will likely focus on optimizing the synthesis of multifunctional isothiocyanates,understanding their complex biological mechanisms,exploring new applications,and highlighting the continued importance of isothiocyanates in modern chemistry and biotechnology.展开更多
The catalytic enantioselective electrophilic amination reaction has emerged as a highly efficient method for synthesizing diverse nitrogen-containing chiral molecules,with the development of various asymmetric catalys...The catalytic enantioselective electrophilic amination reaction has emerged as a highly efficient method for synthesizing diverse nitrogen-containing chiral molecules,with the development of various asymmetric catalysis systems.Chiral phosphoric acids(CPA)have been widely acknowledged as versatile chiral organocatalysts since it was first discovered in 2004,finding application in catalyzing diverse asymmetric reactions.A comprehensive overview of recent advances in CPA-catalyzed asymmetric electrophilic amination reactions using different N-electrophilic reagents,including azo reagents,aryldiazonium salts,and imine derivatives,is presented.Furthermore,insights into future developments in this field are offered.展开更多
A facile method for decarboxylative amination driven by the photoactivity of electron donor-acceptor(EDA)com-plexes assembled from iodide salts and redox-active esters has been proposed.A broad array of acyclic and cy...A facile method for decarboxylative amination driven by the photoactivity of electron donor-acceptor(EDA)com-plexes assembled from iodide salts and redox-active esters has been proposed.A broad array of acyclic and cyclic protected amines were readily synthesized without requiring exogenous transition-metal or photoredox catalysts.Moreover,this ap-proach facilitates late-stage functionalization of complex molecules and is amenable to continuous-flow process on gram scale.展开更多
A transition-metal-free strategy for the synthesis of carboline derivatives via sequential dual C—N bond formation in a one-pot reaction is reported.Using 2,2'-dihalogenated pyridyl biaryls and primary amines as ...A transition-metal-free strategy for the synthesis of carboline derivatives via sequential dual C—N bond formation in a one-pot reaction is reported.Using 2,2'-dihalogenated pyridyl biaryls and primary amines as starting materials,this method efficiently constructs a series ofα-,β-,γ-andδ-carbolines under alkaline conditions.The reaction proceeds smoothly in the presence of lithium tert-butoxide(t-BuOLi)or cesium carbonate(Cs_(2)CO_(3))without requiring transition metal catalysts,demonstrating good functional group tolerance.This approach enables gram-scale synthesis and has been successfully applied to the preparation of the organic material 2,6-CbPy,achieving high conversion efficiency.展开更多
文摘Heterocyclic ketene aminals 1 react with aryl azides 2 to give the titled compounds 3,and in some cases also with the formation of fused heterocycles 4.
文摘An efficient solid-phase synthesis method for novel heterocyclic ketene aminals containing a hydroxyl group has been developed. The loading of the substrate on the resin through the hydroxyl group and the protection of the amine by the Schiff base were the key steps in the synthesis.
文摘Heteroatom aroyl-substituted heterocyclic ketene aminals 1 reacted with 2,3,4,6-tetra-O-acetyl-α-glucopyranosyl bromide 2 under the catalysis of Hg(CN)2 or CaH2 to give E- or Z-O-glycosides of heterocyclic ketene aminals 3 or 4 in moderate yields.
文摘The anion of heterocyclic ketene aminals reacted with 2,4-dini- tro-halobenzenes to give an arylated product through the radical nucleo- philic substitution confirmed by ESR spectroscopy,ESR-spin trapping techni- que,and depression of the reaction rate by the addition of inhibitor.
基金financial supported by National Natural Science Foundation of China(No.21372079)National High Technology Research Development Program of China(863 Program,No. 2011AA10A207)+3 种基金Shanghai Pujiang Program(No.14PJD012)Key Projects in the National Science & Technology Pillar Program(No. 2011BAE06B05)the Fundamental Research Funds for the Central Universitiespartly supported by Australia DC Foundation
文摘An efficient synthetic pathway to 2-oxo-1,2-dihydropyridine-fused 1,3-diaza heterocycles from heterocyclic ketene aminals,phathalic anhydride and ethyl cyanacetate was established.This protocol involved aza-ene reaction/imine-enamine tautomerization/enamine-ester exchange/ring-opening reaction sequence.
基金the National Natural Science Foundation of China (Nos. 21502098, 21672105)the Natural Science Foundation of Tianjin (17JCYBJC19700)the Qindao National Laboratory for Marine Scie nee and Tech no logy, and the State Key Laboratory of Elemento-Organic Chemistry at Nankai University for financial support of this work.
文摘Summary of main observation and conclusion A 4+2 cycloaddition reaction of NH-free benzazetidines with indoles under the catalysis of camphorsulfonic acid was developed. This method shows a broad substrate scope of benzazetidines and indoles, and offers a convenient method for stereoselective synthesis of various cis-2,3-fused indoline aminals. Preliminary mechanistic studies suggest the reaction proceed via a stepwise pathway featuring an electrophilic attack on the benzylic carbon of benzazetidine.
基金Supported by the Guangdong-Hong Kong-Macao Joint Laboratory on Micro-Nano Manufacturing Technology,China(No.2021LSYS004)Guangdong Provincial Key Laboratory of Sustainable Biomimetic Materials and Green Energy,China(No.2024B1212010003)。
文摘Monitoring biogenic amines,which are metabolic byproducts of shrimp spoilage,is crucial for assessing food quality.Currently,most detection methods for biogenic amines suffer from limitations such as time-consuming procedures,complex operations,and delayed results.Colorimetric analysis techniques have gained attention in recent years due to their advantages of short analysis time,simple operation,and suitability for on-site testing.This study successfully developed a series of colorimetric sensor platforms for biogenic amines by loading the natural active ingredient curcumin(CUR)and its derivative of Boron complex BFCUR onto filter paper and electrospun nanofibre films(ENFs),respectively.By analyzing the color response differences of these sensors upon contact with biogenic amines,the colorimetric sensors with superior detection performance were selected and further applied to the visual monitoring and indication of shrimp spoilage processes.
基金supported by the National Natural Science Foundation of China(Nos.22271007,W2431014)Peking University Shenzhen Graduate School+2 种基金State Key Laboratory of Chemical OncogenomicsShenzhen Key Laboratory of Chemical GenomicsShenzhen Bay Laboratory.
文摘Chiral benzylic amines are important motifs in medicines.A dicationic nickel complex of chiral diphosphine(R)-Ph-BPE promotes highly enantioselective reductive amination of aryl alkyl ketones with arylamines using isopropanol as hydrogen source.The reaction is easily scaled up in a gram-scale synthesis using 1 mol% nickel catalyst and it is applied to an asymmetric synthesis of(S)-rivastigmine.Building on this success,we achieved rare examples of asymmetric hydrogen borrowing reactions with arylamines using an Earth-abundant 3d metal,nickel.
基金Supported by The Central Public-Interest Scientific Institution Basal Research Fund,CAFS(2025XT0902)Earmarked for China Agriculture Research System(CARS-46).
文摘The widespread use of herbicides such as glyphosate isopropyl amine salt(GIS)and atrazine(ATZ)poses significant risks to aquatic ecosystems.This study investigated the single and joint acute toxicity of a 1:1 GIS-ATZ mixture on zebrafish(Danio rerio).Acute tests determined 96-h LC_(50) values of 123.41 mg/L for GIS and 103.95 mg/L for ATZ.In the joint toxicity test,these values decreased to 60.96 and 50.88 mg/L,respectively.The Additive Index(AI)analysis revealed a consistent synergistic interaction between the herbicides at all exposure intervals.These findings underscore the enhanced ecological threat of herbicide mixtures and highlight the necessity of considering joint effects in environmental risk assessments.
基金supported by the National Natural Science Foundation of China(32302258,32172317)the Science and Technology Innovation Program of Hunan Province(2024RC3185)+1 种基金Hunan Provincial Natural Science Foundation of China(2023JJ40317)Changsha Municipal Natural Science Foundation(kq2202223).
文摘This study investigated the suppressive effects of Armoracia rusticana(AR)and its three main glucosinolates on both free and bound heterocyclic amines(HAs),along with their mechanisms of free radical quenching using density functional theory.Fish patties were supplemented with varying concentrations of AR(0.5%‒1.5%)and glucosinolates(0.005%‒0.015%),showing a dose-dependent inhibition of HAs and concurrent elimination of free radicals and HAs intermediates.Glucobrassicin demonstrated the highest reactivity,which was verified by frontier orbit analysis and conceptual density functional parameters,consistent with experimental findings.Furthermore,the O-H bond connected to the sulfur atom of glucobrassicin possessed the smallest bond dissociation enthalpy(BDE)value,which indicated that this particular hydrogen atom is most susceptible to react with free radicals.Overall,AR and its glucosinolates,especially glucobrassicin,show promise as natural additives for improving food safety and quality.
基金This research was supported by the National Natural Science Foundation of China （Nos. 21672199 and 21790333） and CAS Interdisciplinary Innovation Team.
文摘A new palladium-catalyzed selective aminomethylation of conjugated 1,3-dienes with aminais via double C-N bond activation is described. This simple method provides an effective and rapid approach for the synthesis of linear a,13-unsaturated allylic amines with perfect regioselectivity. Mechanistic studies disclosed that one palladium catalyst cleaved two distinct C-N bond to furnish a cascade double C-N bond activation, in which an allylic 1,3-diamine and allylic 1,2-diamine were initially formed as key intermediates through the palladium-catalyzed C-N bond activation of aminal and the α,β-unsaturated allylic amine was subsequently produced via palladium-catalyzed C-N bond activation of the allylic diamines.
基金ProjectsupportedbytheMajorStateBasicResearchDevelopmentProgram (No .G2 0 0 0 0 775 0 2 )andtheNationalNaturalScienceFoundationofChina (No .2 9732 0 5 0 )
文摘The stereoselective synthesis of O-maltosides by reacting benzoyl-substituted heterocyclic ketene aminals 1 or 2 with acetylated maltosyl bromide 3 was investigated. Compounds 1 or 2 reacted with 3 in the presence of mercuric cyanide to give O-maltosides 4 or 5 with E-configuration. While 1 reacted with 3 in the presence of calcium hydride to give O-maltosides 6 with Z-configuration.
基金support for this work by Hebei Education Department(No.JZX2024004)Central Guidance on Local Science and Technology Development Fund of Hebei Province(No.236Z1404G)+3 种基金the National Natural Science Foundation of China(Nos.22301060 and 21272053)China Postdoctoral Science Foundation(No.2023M730914)the Natural Science Foundation of Hebei Province(Biopharmaceutical Joint Fund No.B2022206008)Project of Science and Technology Department of Hebei Province(No.22567622H)。
文摘Heterogeneous metal-catalyzed chemical conversions with a recyclable catalyst are very ideal and challenging for sustainable organic synthesis.A new bipyridyl-Mo(IV)-carbon nitride(CN-K/Mo-Bpy)was prepared by supporting molybdenum complex on C_(3)N_(4)-K and characterized by FT-IR,XRD,SEM,XPS and ICP-OES.Heterogeneous CN–Mo-Bpy catalyst can be applied to the direct amination of nitroarenes and arylboronic acid,thus constructing various valuable diarylamines in high to excellent yields with a wide substrate scope and good functional group tolerance.It is worth noting that this heterogeneous catalyst has high chemical stability and can be recycled for at least five times without reducing its activity.
基金supported by the Natural Science Foundation of Guangdong Province(2022A1515012158)the National Science Foundation of China(41977138)+3 种基金the Construction Project of Teaching Quality and Teaching Reform in Guangdong Province(SJD202001)the General University Project of Guangdong Provincial Department of Education(2021KCXTD070 and 2021ZDZX4072)the Key Project of Social Welfare and Basic Research of Zhongshan City(2020B2010)the Start-up Fund from the Zhongshan Institute at the University of Electronic Science and Technology in China(419YKQN12)。
文摘In-depth knowledge of the microbes responsible for biogenic amine(BA)production during soy sauce fermentation remains limited.Herein,the variations in the BA profiles,microbial communities,and microbes involved in BA production during the fermentation of soy sauce through Japanese-type(JP)and Cantonese-type(CP)processes were compared.BA analysis revealed that the most abundant BA species were putrescine,tyramine,and histamine in the later three stages(1187.68,785.16,and 193.20 mg/kg on average,respectively).The BA profiles differed significantly,with CP samples containing higher contents of putrescine,tyramine,and histamine(P<0.05)at the end of fermentation.Metagenomic analysis indicated that BA-producing genes exhibited different abundance profiles,with most genes,including spe A,spe B,arg,spe E,and tyr DC,having higher abundances in microbial communities during the CP process.In total,15 high-quality metagenome-assembled genomes(MAGs)were retrieved,of which 10 encoded at BA production-related genes.Enterococcus faecium(MAG10)and Weissella paramesenteroides(MAG5)might be the major tyramine producers.The high putrescine content in CP might be associated with the high abundance of Staphylococcus gallinarum(MAG8).This study provides a comprehensive understanding of the diversity and abundance of genes involved in BA synthesis,especially at the species level,during food fermentation.
基金the NSFC(No.22472112)the Suzhou Foreign Academician Workstation(No.SWY2022001)for financial supportsthe Soochow Municipal Laboratory for Low Carbon Technologies and Industries.
文摘Nitrogenous compounds(i.e.,amines,amides,nitriles,oximes,amino acids and nitrogen-heterocycles derivatives)are important building blocks for synthetic chemistry,pharmaceuticals,and functional materials.Conventional synthetic strategies involve the use of toxic organic nitrogenous precursors or expensive heterogeneous catalysts under elevated temperatures and pressurized oxygen.Heterogeneous electrocatalysis can initiate the activation of inorganic N sources(i.e.,NH_(3)and NO^(-)_(x))under ambient reactions in liquid phase by applying a small bias,thus allowing the synthesis of value?added nitrogenous compounds from carbonyls,alkenes,keto acids,and even carbon dioxide in a sustainable manner without the use of oxidants/reductants.This review outlines recent de-velopments in electrosynthesis of nitrogenous compounds using inorganic N sources,focusing on reaction mechanisms understanding,the design and optimization of efficient electrocatalysts,and the advances in cell configurations for various C‒N coupling reactions.The limitations and challenges in applications are also discussed.
基金supported by the National Natural Science Foundation of China(No.52100133,No.52222005)the Key R&D Program of Yunnan Province(No.202303AC100008)。
文摘Catalyst-aided regeneration is a promising method for reducing the high regeneration energy consumption of amine-based CO_(2)capture technologies.However,the intrinsic relationship between the properties of the acidic sites and their catalytic activity is controversial.In this study,a series of W-based catalysts supported by ZrTiO_(x)were synthesised,and the effects of the intensity,distribution,and type of acid sites were systematically investigated by quantitatively regulating the acidic site properties.The results indicate stronger acidic sites play a more important role in the catalytic reaction.Moreover,the catalysts showed excellent performance only if the Br?nsted acid sites(BASs)and Lewis acid sites(LASs)coexisted.During the catalytic reaction,the BASs facilitated deprotonation,and the LASs promoted the decomposition of carbamates.The ratio of BASs to LASs(B/L)was a critical factor for catalytic activity,wherein optimal performance was achieved when the B/L ratio was close to 1.The 10%HPW/ZrTiO_(x)composite performed better than WO_(3)/ZrTiO_(x)and HSiW/ZrTiO_(x)because it had a stronger acid intensity and a suitable B/L ratio.As a result,the relative heat duty was reduced by 47%compared to 30%aqueous MEA,and the maximum CO_(2)desorption rate was increased by 83%.The Bader charge indicated that the W atoms of HPW/ZrTiO_(x)lost more electrons(0.18)than those of WO_(3)/ZrTiO_(x),which can weaken the O±H bond energy.Consequently,the calculated deprotonation energy is as low as 257 kJ mol^(-1)for HPW/ZrTiO_(x).
文摘Isothiocyanates(ITCs)are an important class of organic compounds characterized by the functional group R-N=C=S.These functional groups are widely found in multiple natural products and pharmaceutical important drugs.Moreover,due to their high and versatile reactivity,they are widely used as an intermediate in organic synthesis.Keeping in view ITCs importance,this review summarizes their synthesis from nitrogen rich raw materials like amines,isocyanides,azides and some other compounds like oximes.Besides their synthesis,their application in organic compound synthesis as an intermediate will also be covered.Future research will likely focus on optimizing the synthesis of multifunctional isothiocyanates,understanding their complex biological mechanisms,exploring new applications,and highlighting the continued importance of isothiocyanates in modern chemistry and biotechnology.
文摘The catalytic enantioselective electrophilic amination reaction has emerged as a highly efficient method for synthesizing diverse nitrogen-containing chiral molecules,with the development of various asymmetric catalysis systems.Chiral phosphoric acids(CPA)have been widely acknowledged as versatile chiral organocatalysts since it was first discovered in 2004,finding application in catalyzing diverse asymmetric reactions.A comprehensive overview of recent advances in CPA-catalyzed asymmetric electrophilic amination reactions using different N-electrophilic reagents,including azo reagents,aryldiazonium salts,and imine derivatives,is presented.Furthermore,insights into future developments in this field are offered.
文摘A facile method for decarboxylative amination driven by the photoactivity of electron donor-acceptor(EDA)com-plexes assembled from iodide salts and redox-active esters has been proposed.A broad array of acyclic and cyclic protected amines were readily synthesized without requiring exogenous transition-metal or photoredox catalysts.Moreover,this ap-proach facilitates late-stage functionalization of complex molecules and is amenable to continuous-flow process on gram scale.
基金Project supported by the National Natural Science Foundation of China(No.22371303)the Zhongshan Municipal Bureau of Science and Technology(Nos.2021B2014,CXTD2022013)the Shanghai Rising-Star Program(21QA1411000)。
文摘A transition-metal-free strategy for the synthesis of carboline derivatives via sequential dual C—N bond formation in a one-pot reaction is reported.Using 2,2'-dihalogenated pyridyl biaryls and primary amines as starting materials,this method efficiently constructs a series ofα-,β-,γ-andδ-carbolines under alkaline conditions.The reaction proceeds smoothly in the presence of lithium tert-butoxide(t-BuOLi)or cesium carbonate(Cs_(2)CO_(3))without requiring transition metal catalysts,demonstrating good functional group tolerance.This approach enables gram-scale synthesis and has been successfully applied to the preparation of the organic material 2,6-CbPy,achieving high conversion efficiency.
