Chiral cyclic amino alcohols with contiguous stereocenters are key building blocks in the synthesis of bioactive molecules and pharmaceuticals.Artificial cascade biocatalysis represents an attractive method for the sy...Chiral cyclic amino alcohols with contiguous stereocenters are key building blocks in the synthesis of bioactive molecules and pharmaceuticals.Artificial cascade biocatalysis represents an attractive method for the synthesis of chiral molecules bearing multiple stereocenters from readily available materials.Here we reported an artificial cascade biocatalysis comprising an epoxide hydrolase,an alcohol dehydrogenase,and a reductive aminase or an amine dehydrogenase.It can be utilized to access all four stereoisomers of 2-aminocyclohexanol with two contiguous stereocenters in high yields(up to 95%)and excellent stereoselectivity(up to 98%de)starting from readily available cyclohexene oxide without isolation of the intermediates.Additionally,the biocatalytic cascade has been successfully extended to the production of structurally diverse 2-(alkylamino)cyclohexanols by replacing ammonia with different organic amines.展开更多
Chiral N-substituted amino amides and esters are ubiquitous scaffolds in pesticides and pharmaceutical chemicals,but their asymmetric synthesis remains challenging especially for those with multiple chiral centers.In ...Chiral N-substituted amino amides and esters are ubiquitous scaffolds in pesticides and pharmaceutical chemicals,but their asymmetric synthesis remains challenging especially for those with multiple chiral centers.In this study,IR104 from Streptomyces aureocirculatus was identified from 157 wild-type imine reductases for the synthesis of(S)-2-((R)-2-oxo-4-propylpyrrolidin-1-yl)butanamide(antiepileptic drug Brivaracetam)via dynamic kinetic resolution reductive amination from ethyl 3-formylhexanoate and(S)-2-aminobutylamide with high diastereoselectivity.To further improve the catalytic efficiency of IR104,its mutant D191E/L195I/E253S/M258A(M3)was identified by saturation mutagenesis and iterative combinatorial mutagenesis,which exhibited a 102-fold increase in the catalytic efficiency relative to that of wild-type enzyme and high diastereoselectivity(98:2 d.r.).Crystal structural analysis and molecular dynamics simulations provided some insights into the molecular basis for the improved activity of the mutant enzyme.The imine reductase identified in this study could accept chiral amino amides/esters as amino donors for the dynamic kinetic resolution reductive amination of racemicα-substituted aldehydo-esters,expanding the substrate scope of imine reductases in the dynamic kinetic resolution-reductive amination.Finally,IR104-M3 was successfully used for the preparation of Brivaracetam at gram scale.Using this mutant,various N-substituted amino amides/esters with two chiral centers were also synthesized with up to 99:1 d.r.and 96%yields and subsequently converted intoγ-andδ-lactams,providing an efficient protocol for the synthesis of these important compounds via enzymatic dynamic kinetic resolution-reductive amination from simple building blocks.展开更多
Primary diamines play an important role in the chemical industry,where they are widely used as raw materials for the manufacture of pharmaceuticals and polymers.Currently,primary diamines are mainly derived from petro...Primary diamines play an important role in the chemical industry,where they are widely used as raw materials for the manufacture of pharmaceuticals and polymers.Currently,primary diamines are mainly derived from petroleum,while harsh or toxic conditions are often needed.Biomass is abundant and renewable,which serves as a promising alternative raw material to produce primary diamines.This review primarily focuses on the synthesis of 2,5-bis(aminomethyl)furan(BAMF),a bio-based diamine with potential as a biomonomer for polyamides and polyureas.Specifically,this review emphasizes the synthesis of BAMF fromthree biomass-derived alcohols and aldehydes,namely 5-hydroxymethylfurfural(HMF),2,5-bis(hydroxymethyl)furan(BHMF),and 2,5-diformylfuran(DFF).These are the key substrates to get BAMF and could be readily obtained from carbohydrates.Even though great effort has been put into the synthesis of BAMF,it remains a tough problem to obtain BAMF with a high yield at a low cost due to the inevitable side reactions,such as unwanted hydrogenation reactions and condensation reactions.Many strategies have been proposed to solve this problem,such as the hydrogen-borrowing strategy and stepwise reductive amination strategy.Herein,we will summarize the key advancements in this area,and discuss the challenges that need to be responded in the future,hoping to provide an insight into the design and development of a more efficient system for the production of biomass-derived diamines.展开更多
Synthesis of primary amines from alcohols is an economical and green route to access high-value N-compounds.However,challenges remain to develop both cost-effective and efficient catalysts.In this study,we developed a...Synthesis of primary amines from alcohols is an economical and green route to access high-value N-compounds.However,challenges remain to develop both cost-effective and efficient catalysts.In this study,we developed a Ru-Co/ZrO_(2)single-atom alloy catalyst which afforded diverse primary amines from alcohols in the presence of ammonia and hydrogen with exceptional conversion(up to 90%)and selectivity(80%)under mild conditions(0.7 MPa NH_(3),0.3 MPa H_(2),160℃)and exhibited satisfactory stability upon regeneration.The turnover rate was approximately 8.4 times higher than that observed over the Co/ZrO_(2)catalyst.Characterizations indicated that the alloyed Ru facilitated the reduction of Co,strengthened the interaction with H_(2)and mitigated the over-strong adsorption of aldehyde intermediates.These combined effects contributed significantly to the enhanced catalytic performances.This work presents a promising strategy for the development of advanced catalysts in the amination of alcohols.展开更多
N-substituted furfurylamines(FAs)are valuable precursors for producing pharmacologically active compounds and polymers.However,enzymatic synthesis of the type of chemicals is still in its infancy.Here we report an imi...N-substituted furfurylamines(FAs)are valuable precursors for producing pharmacologically active compounds and polymers.However,enzymatic synthesis of the type of chemicals is still in its infancy.Here we report an imine reductase from Streptomyces albidoflavus(SaIRED)for the reductive amination of biobased furans.A simple,fast and interference-resistant high-throughput screening(HTS)method was developed,based on the coloration reaction of carbonyl compounds with 2,4-dinitrophenylhydrazine.The reductive amination activity of IREDs can be directly indicated by a colorimetric assay.With the reductive amination of furfural with allylamine as the model reaction,SaIRED with the activity of 4.8 U mg^(-1) was subjected to three rounds of protein engineering and screening by this HTS method,affording a high-activity tri-variant I127V/D241A/A242T(named M3,20.2 U mg^(-1)).The variant M3 showed broad substrate scope,and enabled efficient reductive amination of biobased furans with a variety of amines including small aliphatic amines and sterically hindered amines,giving the target FAs in yields up to>99%.In addition,other variants were identified for preparative-scale synthesis of commercially interesting amines such as N-2-(methylsulfonyl)ethyl-FA by the screen method,with isolated yields up to 87%and turnover numbers up to 9700 for enzyme.Gram-scale synthesis of N-allyl-FA,a valuable building block and potential polymer monomer,was implemented at 0.25 mol L^(-1) substrate loading by a whole-cell catalyst incorporating variant M3,with 4.7 g L^(-1) h^(-1) space-time yield and 91%isolated yield.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
Oxidation of organic amines(OAs)or aromatic hydrocarbons(AHs)produces carbonyls,which further react with OAs to form carbonyl-amine condensation products,threatening environmental quality and human health.However,ther...Oxidation of organic amines(OAs)or aromatic hydrocarbons(AHs)produces carbonyls,which further react with OAs to form carbonyl-amine condensation products,threatening environmental quality and human health.However,there is still a lack of systematic understanding of the carbonyl-amine condensation reaction processes of OAs or between OAs and AHs,and subsequent environmental health impact.This work systematically investigated the carbonyl-amine condensation coupled ozonolysis kinetics,reaction mechanism,secondary organic aerosol(SOA)formation and cytotoxicity fromthe mixture of dipropylamine(DPA)and styrene(STY)by a combined method of productmass spectrometry identification,particle property analysis and cell exposure evaluation.The results from ozonolysis of DPA and STY mixture revealed that STY inhibited the ozonolysis of DPA to different degrees to accelerate its own decay rate.The barycenter of carbonyl-amine condensation reactionswas shifted from inside of DPA to between DPA and STY,which accelerated STY ozonolysis,but slowed down DPA ozonolysis.For the first time,ozonolysis of DPA and STY mixture to complex carbonyl-amine condensation products through the reactions of DPA with its carbonyl products,DPA with STY’s carbonyl products and DPA’s bond breakage product with STY’s carbonyl products was confirmed.These condensation products significantly contributed to the formation and growth of SOA.The SOA containing particulate carbonyl-amine condensation products showed definite cytotoxicity.These findings are helpful to deeply and comprehensively understand the transformation,fate and environmental health effects of mixed organics in atmospheric environment.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
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
Gold-catalyzed amination reactions based on azides viaα-imino gold carbene intermediates have attracted extensive attention in the past decades because this methodology leads to the facile and efficient construction ...Gold-catalyzed amination reactions based on azides viaα-imino gold carbene intermediates have attracted extensive attention in the past decades because this methodology leads to the facile and efficient construction of synthetically useful N-containing molecules,especially valuable N-heterocycles.However,successful examples of intermolecular generation ofα-imino gold carbenes by using azides as amination reagents are rarely explored probably due to the weak nucleophilicity of azides.Herein,we disclose an efficient gold-catalyzed intermolecular aminative cyclopropanation of ynamides with the allyl azides,enabling flexible synthesis of a wide range of valuable 3-azabicyclo[3.1.0]hex-2-ene derivatives in good to excellent yields with excellent diastereoselectivities.Importantly,this protocol represents the first use of allyl azide as an efficient amination reagent in gold-catalyzed alkyne amination reactions.展开更多
Amines represent fundamental motifs in various chemical contexts and are widely used in agrochemicals and pharmaceuticals.The development of earth-abundant metal-based heterogeneous catalysts for the synthesis amines ...Amines represent fundamental motifs in various chemical contexts and are widely used in agrochemicals and pharmaceuticals.The development of earth-abundant metal-based heterogeneous catalysts for the synthesis amines remains an important goal in terms of chemical research and industrial application/manufacture.Herein,we developed an efficient and highly selective nitrogen-doped nickel catalyst enriched with Lewis acid sites,which has been applied for to the hydrogenative coupling of nitriles and amines with molecular hydrogen for the synthesis of a train of functionalised and structurally diverse secondary and tertiary amines.Furthermore,catalytic hydrogenation and deuteration of nitriles were achieved under milder conditions,yielding a series of primary amines and deuterated amines with high deuterium incorporation.展开更多
[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane was synthesized,using tert-butyldimethylsilane(TBDMS)and 1,2-epoxy-4-vinylcyclohexane(EVC)as the main raw materials and tris(triphenylphosphine)chlororhodium(I)[...[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane was synthesized,using tert-butyldimethylsilane(TBDMS)and 1,2-epoxy-4-vinylcyclohexane(EVC)as the main raw materials and tris(triphenylphosphine)chlororhodium(I)[RhCl(Ph3P)3]as the catalyst.[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane is a novel kind of silicon-containing epoxide.The factors affecting the reaction yield,such as catalyst use,reaction time and reaction temperature,were investigated,and the synthesized product was characterized and analyzed by FT-IR and 1H-NMR.A series of amine-curing resins were prepared with[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane,bisphenol A epoxy resin(E-51)and modified amine(593 amine).The mechanical properties of cured splines with the different proportions of amine-curing resins were tested.When the content of 593 amine was 20%,the content of E-51 was 75%and the amount of[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane was 5%,the mechanical properties of the cured splines were the best with the tensile strength being 23.3 MPa,the elongation at break being 7.8%,and the Young's modulus being 421.3 MPa.展开更多
A nickel-catalyzed C(sp^(2))–H alkynylation of unprotected α-substituted benzylamines is achieved by utilizing a transient directing group. The combination of a TDG with a nickel catalyst significantly improves the ...A nickel-catalyzed C(sp^(2))–H alkynylation of unprotected α-substituted benzylamines is achieved by utilizing a transient directing group. The combination of a TDG with a nickel catalyst significantly improves the reaction step and atom economy. It has been investigated that the 2,4,6-trimethylpyridine ligand was critical to achieve the optimized reactivity. This protocol provides a straightforward route for synthesizing the alkynylated free benzylamines, featuring good substrate compatibility and monoselectivity.展开更多
The biphasic solvent is a promising solution to reduce regeneration energy consumption in CO_(2) capture.However,most current biphasic solvents suffer from high viscosity and poor desorption of the rich phase.To the i...The biphasic solvent is a promising solution to reduce regeneration energy consumption in CO_(2) capture.However,most current biphasic solvents suffer from high viscosity and poor desorption of the rich phase.To the issues,a novel pentamethyldiethylenetriamine(PMDETA)-2-amino-2-methyl-1-propanol(AMP)/diethylenetriamine(DETA)-sulfolane biphasic solvent was developed.The mechanism of AMP affecting CO_(2) recycling capacity was analyzed.By adjusting the ratio of AMP and DETA,the absorption and desorption performance were balanced,and the recycling capacity and renewable energy consumption of the absorbent were improved.For the P_(2.4)A_(0.8)D_(0.8)S_(2) biphasic solvent,the CO_(2) loading of the rich phase was 5.87 mol/L,and the proportion of the rich phase volume ratio was 35%,which surpasses most reported biphasic solvents.The viscosity of the absorbent significantly decreased from 527.00 mPa·s to 92.26 mPa·s,attributed to the beneficial effect of AMP.Thermodynamic analysis showed that the biphasic solvent produced a lower regeneration energy consumption of 1.70 GJ/t CO_(2),which was 57%lower than that of monoethanolamine(MEA).Overall,the PMDETA-AMP/DETA-sulfolane biphasic solvent exhibited cycle capacity,which provided new insights for the designing of biphasic solvent.展开更多
Organic amine pesticides(OAPs)are widely used in modern agriculture and these compounds can contaminate drinking water sources in different ways.However,there is a lack of data on the occurrence of OAPs in drinking wa...Organic amine pesticides(OAPs)are widely used in modern agriculture and these compounds can contaminate drinking water sources in different ways.However,there is a lack of data on the occurrence of OAPs in drinking water and their potential human health risks.In this study,tapwater(TW)and bottledwater(BW)sampleswere collected from eight cities in the Yangtze River Delta urban agglomeration in China,and their OAP levelswere analyzed using high-throughput organic analysis testing coupled with high-volume solid-phase extraction(Hi-throat/Hi-volume SPE techniques).This study is the first to systematically characterize the trace levels of OAPs in drinking water in China.Our findings indicated that the total concentration of OAPs(OAPs)in TW(average 11.06±4.99 ng/L)was 29.4%higher than in BW(average 8.55±3.98 ng/L)and fewer kinds(7)of OAPs were detected in BW.Furthermore,the long-term intake of TW in some areas was linked to carcinogenic risks even at an acceptable OAP range,particularly in males,with molinate being the major contributor(61.3%)to OAP exposure.Further analysis revealed that the occurrence and health risks of OAPs in drinking water were mainly influenced by the quality of water sources and the technologies adopted in drinking water treatment plants(DWTPs).Furthermore,our findings demonstrated that advanced treatment technologies such as nanofiltration could more effectively remove OAPs in raw water(up to 87.5%).Therefore,our findings highlighted the importance of selecting appropriate advanced treatment technologies in DWTPs.展开更多
An electronic circular dichroism(ECD)-based chiroptical sensing method has been developed forβ-andγ-chiral primary amines via a C-H activation reaction.With the addition of Pd(OAc)_(2),the flexible remote chiral pri...An electronic circular dichroism(ECD)-based chiroptical sensing method has been developed forβ-andγ-chiral primary amines via a C-H activation reaction.With the addition of Pd(OAc)_(2),the flexible remote chiral primary amine fragment in the bidentate ligand intermediate was fixed to form a cyclopalladium complex,producing an intense ECD response.The correlation between the sign of Cotton effects and the absolute configuration of substrates was proposed,together with theoretical verification using timedependent density functional theory(TDDFT).Chiroptical sensing of an important drug raw material was performed to provide rapid and accurate information on the absolute optical purity.This work introduces an alternative perspective of C-H activation reaction as well as a feasible chiroptical sensing method of remote chiral amines.展开更多
Although supported solid amine adsorbents have attracted great attention for CO_(2) capture,critical chemical deactivation problems including oxidative degradation and urea formation have severely restricted their pra...Although supported solid amine adsorbents have attracted great attention for CO_(2) capture,critical chemical deactivation problems including oxidative degradation and urea formation have severely restricted their practical applications for flue gas CO_(2) capture.In this work,we reveal that the nature of surface hydroxyl groups(metal hydroxyl Al–OH and nonmetal hydroxyl Si–OH)plays a key role in the deactivation mechanisms.The polyethyleneimine(PEI)supported on Al–OH-containing substrates suffers from severe oxidative degradation during the CO_(2) capture step due to the breakage of amine-support hydrogen bonding networks,but exhibits an excellent anti-urea formation feature by preventing dehydration of carbamate products under a pure CO_(2) regeneration atmosphere.In contrast,PEI supported on Si–OHcontaining substrates exhibits excellent anti-oxidative stability under simulated flue gas conditions by forming a robust hydrogen bonding protective network with Si–OH,but suffers from obvious urea formation during the pure CO_(2) regeneration step.We also reveal that the urea formation problem for PEI-SBA-15 can be avoided by the incorporation of an OH-containing PEG additive.Based on the intrinsic understanding of degradation mechanisms,we successfully synthesized an adsorbent 40PEI-20PEG-SBA-15 that demonstrates outstanding stability and retention of a high CO_(2) capacity of 2.45 mmol g^(−1) over 1000 adsorption–desorption cycles,together with negligible capacity loss during aging in simulated flue gas(10%CO_(2)+5%O_(2)+3%H_(2)O)for one month at 60–70℃.We believe this work makes great contribution to the advancement in the field of ultra-stable solid amine-based CO_(2) capture materials.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
Point source CO_(2) capture(PSCC)is crucial for decarbonizing various industrial sectors,while direct air capture(DAC)holds promise for removing CO_(2) directly from the air.Sorbents play a critical role in both techn...Point source CO_(2) capture(PSCC)is crucial for decarbonizing various industrial sectors,while direct air capture(DAC)holds promise for removing CO_(2) directly from the air.Sorbents play a critical role in both technologies,with their performances,efficiency,cost,etc.,largely depending on which type is used(physical or chemical).Solid amine sorbents(SAS)employed in the chemical adsorption of CO_(2) are suitable for both PSCC and DAC.SAS offer significant advantages over liquid amines such as monoethanolamine(MEA),due to their ability to perform cyclic adsorption–desorption with much lower energy requirement.The environmental concern associated with MEA can be mitigated by SAS.Support materials have a significantly important role in stabilizing amine and enhancing stability and kinetics;varieties of support materials have been screened at a laboratory scale.One promising support material is a silica gel(SG),which is commercially available and attractive for designing cost-effective sorbents for large-scale CO_(2) capture.Various impregnation methods such as physical adsorption and covalent functionalization have been employed to functionalize silica surfaces with amines.This review provided a comprehensive critical analysis of SG-based SAS for CO_(2) capture.We discussed and evaluated them in terms of their adsorption capacity,adsorption,and desorption conditions,and the kinetics involved in these processes.Finally,we proposed a few recommendations for further development of low-cost,lower carbon footprint SAS for large-scale deployment of CO_(2) capture technology.展开更多
文摘Chiral cyclic amino alcohols with contiguous stereocenters are key building blocks in the synthesis of bioactive molecules and pharmaceuticals.Artificial cascade biocatalysis represents an attractive method for the synthesis of chiral molecules bearing multiple stereocenters from readily available materials.Here we reported an artificial cascade biocatalysis comprising an epoxide hydrolase,an alcohol dehydrogenase,and a reductive aminase or an amine dehydrogenase.It can be utilized to access all four stereoisomers of 2-aminocyclohexanol with two contiguous stereocenters in high yields(up to 95%)and excellent stereoselectivity(up to 98%de)starting from readily available cyclohexene oxide without isolation of the intermediates.Additionally,the biocatalytic cascade has been successfully extended to the production of structurally diverse 2-(alkylamino)cyclohexanols by replacing ammonia with different organic amines.
文摘Chiral N-substituted amino amides and esters are ubiquitous scaffolds in pesticides and pharmaceutical chemicals,but their asymmetric synthesis remains challenging especially for those with multiple chiral centers.In this study,IR104 from Streptomyces aureocirculatus was identified from 157 wild-type imine reductases for the synthesis of(S)-2-((R)-2-oxo-4-propylpyrrolidin-1-yl)butanamide(antiepileptic drug Brivaracetam)via dynamic kinetic resolution reductive amination from ethyl 3-formylhexanoate and(S)-2-aminobutylamide with high diastereoselectivity.To further improve the catalytic efficiency of IR104,its mutant D191E/L195I/E253S/M258A(M3)was identified by saturation mutagenesis and iterative combinatorial mutagenesis,which exhibited a 102-fold increase in the catalytic efficiency relative to that of wild-type enzyme and high diastereoselectivity(98:2 d.r.).Crystal structural analysis and molecular dynamics simulations provided some insights into the molecular basis for the improved activity of the mutant enzyme.The imine reductase identified in this study could accept chiral amino amides/esters as amino donors for the dynamic kinetic resolution reductive amination of racemicα-substituted aldehydo-esters,expanding the substrate scope of imine reductases in the dynamic kinetic resolution-reductive amination.Finally,IR104-M3 was successfully used for the preparation of Brivaracetam at gram scale.Using this mutant,various N-substituted amino amides/esters with two chiral centers were also synthesized with up to 99:1 d.r.and 96%yields and subsequently converted intoγ-andδ-lactams,providing an efficient protocol for the synthesis of these important compounds via enzymatic dynamic kinetic resolution-reductive amination from simple building blocks.
基金financially supported by China Scholarship Council,Science and Technology Project of the State Administration for Market Regulation(2022MK111)the Fundamental Research Funds for the Central Universities.
文摘Primary diamines play an important role in the chemical industry,where they are widely used as raw materials for the manufacture of pharmaceuticals and polymers.Currently,primary diamines are mainly derived from petroleum,while harsh or toxic conditions are often needed.Biomass is abundant and renewable,which serves as a promising alternative raw material to produce primary diamines.This review primarily focuses on the synthesis of 2,5-bis(aminomethyl)furan(BAMF),a bio-based diamine with potential as a biomonomer for polyamides and polyureas.Specifically,this review emphasizes the synthesis of BAMF fromthree biomass-derived alcohols and aldehydes,namely 5-hydroxymethylfurfural(HMF),2,5-bis(hydroxymethyl)furan(BHMF),and 2,5-diformylfuran(DFF).These are the key substrates to get BAMF and could be readily obtained from carbohydrates.Even though great effort has been put into the synthesis of BAMF,it remains a tough problem to obtain BAMF with a high yield at a low cost due to the inevitable side reactions,such as unwanted hydrogenation reactions and condensation reactions.Many strategies have been proposed to solve this problem,such as the hydrogen-borrowing strategy and stepwise reductive amination strategy.Herein,we will summarize the key advancements in this area,and discuss the challenges that need to be responded in the future,hoping to provide an insight into the design and development of a more efficient system for the production of biomass-derived diamines.
文摘Synthesis of primary amines from alcohols is an economical and green route to access high-value N-compounds.However,challenges remain to develop both cost-effective and efficient catalysts.In this study,we developed a Ru-Co/ZrO_(2)single-atom alloy catalyst which afforded diverse primary amines from alcohols in the presence of ammonia and hydrogen with exceptional conversion(up to 90%)and selectivity(80%)under mild conditions(0.7 MPa NH_(3),0.3 MPa H_(2),160℃)and exhibited satisfactory stability upon regeneration.The turnover rate was approximately 8.4 times higher than that observed over the Co/ZrO_(2)catalyst.Characterizations indicated that the alloyed Ru facilitated the reduction of Co,strengthened the interaction with H_(2)and mitigated the over-strong adsorption of aldehyde intermediates.These combined effects contributed significantly to the enhanced catalytic performances.This work presents a promising strategy for the development of advanced catalysts in the amination of alcohols.
文摘N-substituted furfurylamines(FAs)are valuable precursors for producing pharmacologically active compounds and polymers.However,enzymatic synthesis of the type of chemicals is still in its infancy.Here we report an imine reductase from Streptomyces albidoflavus(SaIRED)for the reductive amination of biobased furans.A simple,fast and interference-resistant high-throughput screening(HTS)method was developed,based on the coloration reaction of carbonyl compounds with 2,4-dinitrophenylhydrazine.The reductive amination activity of IREDs can be directly indicated by a colorimetric assay.With the reductive amination of furfural with allylamine as the model reaction,SaIRED with the activity of 4.8 U mg^(-1) was subjected to three rounds of protein engineering and screening by this HTS method,affording a high-activity tri-variant I127V/D241A/A242T(named M3,20.2 U mg^(-1)).The variant M3 showed broad substrate scope,and enabled efficient reductive amination of biobased furans with a variety of amines including small aliphatic amines and sterically hindered amines,giving the target FAs in yields up to>99%.In addition,other variants were identified for preparative-scale synthesis of commercially interesting amines such as N-2-(methylsulfonyl)ethyl-FA by the screen method,with isolated yields up to 87%and turnover numbers up to 9700 for enzyme.Gram-scale synthesis of N-allyl-FA,a valuable building block and potential polymer monomer,was implemented at 0.25 mol L^(-1) substrate loading by a whole-cell catalyst incorporating variant M3,with 4.7 g L^(-1) h^(-1) space-time yield and 91%isolated yield.
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supported by the National Natural Science Foundation of China(Nos.42177354 and 42020104001)the National Key R&D Program of China(No.2019YFC0214402)+1 种基金the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01Z032)Guangdong Basic and Applied Basic Research Foundation(No.2019B151502064).
文摘Oxidation of organic amines(OAs)or aromatic hydrocarbons(AHs)produces carbonyls,which further react with OAs to form carbonyl-amine condensation products,threatening environmental quality and human health.However,there is still a lack of systematic understanding of the carbonyl-amine condensation reaction processes of OAs or between OAs and AHs,and subsequent environmental health impact.This work systematically investigated the carbonyl-amine condensation coupled ozonolysis kinetics,reaction mechanism,secondary organic aerosol(SOA)formation and cytotoxicity fromthe mixture of dipropylamine(DPA)and styrene(STY)by a combined method of productmass spectrometry identification,particle property analysis and cell exposure evaluation.The results from ozonolysis of DPA and STY mixture revealed that STY inhibited the ozonolysis of DPA to different degrees to accelerate its own decay rate.The barycenter of carbonyl-amine condensation reactionswas shifted from inside of DPA to between DPA and STY,which accelerated STY ozonolysis,but slowed down DPA ozonolysis.For the first time,ozonolysis of DPA and STY mixture to complex carbonyl-amine condensation products through the reactions of DPA with its carbonyl products,DPA with STY’s carbonyl products and DPA’s bond breakage product with STY’s carbonyl products was confirmed.These condensation products significantly contributed to the formation and growth of SOA.The SOA containing particulate carbonyl-amine condensation products showed definite cytotoxicity.These findings are helpful to deeply and comprehensively understand the transformation,fate and environmental health effects of mixed organics in atmospheric environment.
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.
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financial support from the National Natural Science Foundation of China(Nos.22125108,22331004 and 22121001)Yunnan Normal University,Applied Basic Research Projects of Yunnan Province(No.202101AT070217)+1 种基金the Jiangxi Provincial Natural Science Foundation(No.20224BAB213013)the Jiangxi Provincial Department of Education in Science and Technology Program Project(No.GJJ210906)。
文摘Gold-catalyzed amination reactions based on azides viaα-imino gold carbene intermediates have attracted extensive attention in the past decades because this methodology leads to the facile and efficient construction of synthetically useful N-containing molecules,especially valuable N-heterocycles.However,successful examples of intermolecular generation ofα-imino gold carbenes by using azides as amination reagents are rarely explored probably due to the weak nucleophilicity of azides.Herein,we disclose an efficient gold-catalyzed intermolecular aminative cyclopropanation of ynamides with the allyl azides,enabling flexible synthesis of a wide range of valuable 3-azabicyclo[3.1.0]hex-2-ene derivatives in good to excellent yields with excellent diastereoselectivities.Importantly,this protocol represents the first use of allyl azide as an efficient amination reagent in gold-catalyzed alkyne amination reactions.
文摘Amines represent fundamental motifs in various chemical contexts and are widely used in agrochemicals and pharmaceuticals.The development of earth-abundant metal-based heterogeneous catalysts for the synthesis amines remains an important goal in terms of chemical research and industrial application/manufacture.Herein,we developed an efficient and highly selective nitrogen-doped nickel catalyst enriched with Lewis acid sites,which has been applied for to the hydrogenative coupling of nitriles and amines with molecular hydrogen for the synthesis of a train of functionalised and structurally diverse secondary and tertiary amines.Furthermore,catalytic hydrogenation and deuteration of nitriles were achieved under milder conditions,yielding a series of primary amines and deuterated amines with high deuterium incorporation.
基金Funded by the National Natural Science Foundation of China(No.21865017)。
文摘[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane was synthesized,using tert-butyldimethylsilane(TBDMS)and 1,2-epoxy-4-vinylcyclohexane(EVC)as the main raw materials and tris(triphenylphosphine)chlororhodium(I)[RhCl(Ph3P)3]as the catalyst.[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane is a novel kind of silicon-containing epoxide.The factors affecting the reaction yield,such as catalyst use,reaction time and reaction temperature,were investigated,and the synthesized product was characterized and analyzed by FT-IR and 1H-NMR.A series of amine-curing resins were prepared with[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane,bisphenol A epoxy resin(E-51)and modified amine(593 amine).The mechanical properties of cured splines with the different proportions of amine-curing resins were tested.When the content of 593 amine was 20%,the content of E-51 was 75%and the amount of[2-(3,4-epoxy-cyclohexyl)ethyl]dimethyltert-butylsilane was 5%,the mechanical properties of the cured splines were the best with the tensile strength being 23.3 MPa,the elongation at break being 7.8%,and the Young's modulus being 421.3 MPa.
基金supported financially by the Excellent Going Abroad Expert's Training Program in Hebei Province (No. 201940)the Hebei Natural Science Foundation of China (No. H2020208030)the S & T Program of Hebei (No. 22567607H) for financial support。
文摘A nickel-catalyzed C(sp^(2))–H alkynylation of unprotected α-substituted benzylamines is achieved by utilizing a transient directing group. The combination of a TDG with a nickel catalyst significantly improves the reaction step and atom economy. It has been investigated that the 2,4,6-trimethylpyridine ligand was critical to achieve the optimized reactivity. This protocol provides a straightforward route for synthesizing the alkynylated free benzylamines, featuring good substrate compatibility and monoselectivity.
基金supported by the Key R&D Program of Yunnan Province(No.202303AC100008)the National Natural Science Foundation of China(No.52100133)the Major Science and Technology-Special Plan“Unveiling and Leading”Project of Shanxi Province(No.202201050201011).
文摘The biphasic solvent is a promising solution to reduce regeneration energy consumption in CO_(2) capture.However,most current biphasic solvents suffer from high viscosity and poor desorption of the rich phase.To the issues,a novel pentamethyldiethylenetriamine(PMDETA)-2-amino-2-methyl-1-propanol(AMP)/diethylenetriamine(DETA)-sulfolane biphasic solvent was developed.The mechanism of AMP affecting CO_(2) recycling capacity was analyzed.By adjusting the ratio of AMP and DETA,the absorption and desorption performance were balanced,and the recycling capacity and renewable energy consumption of the absorbent were improved.For the P_(2.4)A_(0.8)D_(0.8)S_(2) biphasic solvent,the CO_(2) loading of the rich phase was 5.87 mol/L,and the proportion of the rich phase volume ratio was 35%,which surpasses most reported biphasic solvents.The viscosity of the absorbent significantly decreased from 527.00 mPa·s to 92.26 mPa·s,attributed to the beneficial effect of AMP.Thermodynamic analysis showed that the biphasic solvent produced a lower regeneration energy consumption of 1.70 GJ/t CO_(2),which was 57%lower than that of monoethanolamine(MEA).Overall,the PMDETA-AMP/DETA-sulfolane biphasic solvent exhibited cycle capacity,which provided new insights for the designing of biphasic solvent.
基金supported by the National Key Research and Development Program of China(No.2019YFD1100203).
文摘Organic amine pesticides(OAPs)are widely used in modern agriculture and these compounds can contaminate drinking water sources in different ways.However,there is a lack of data on the occurrence of OAPs in drinking water and their potential human health risks.In this study,tapwater(TW)and bottledwater(BW)sampleswere collected from eight cities in the Yangtze River Delta urban agglomeration in China,and their OAP levelswere analyzed using high-throughput organic analysis testing coupled with high-volume solid-phase extraction(Hi-throat/Hi-volume SPE techniques).This study is the first to systematically characterize the trace levels of OAPs in drinking water in China.Our findings indicated that the total concentration of OAPs(OAPs)in TW(average 11.06±4.99 ng/L)was 29.4%higher than in BW(average 8.55±3.98 ng/L)and fewer kinds(7)of OAPs were detected in BW.Furthermore,the long-term intake of TW in some areas was linked to carcinogenic risks even at an acceptable OAP range,particularly in males,with molinate being the major contributor(61.3%)to OAP exposure.Further analysis revealed that the occurrence and health risks of OAPs in drinking water were mainly influenced by the quality of water sources and the technologies adopted in drinking water treatment plants(DWTPs).Furthermore,our findings demonstrated that advanced treatment technologies such as nanofiltration could more effectively remove OAPs in raw water(up to 87.5%).Therefore,our findings highlighted the importance of selecting appropriate advanced treatment technologies in DWTPs.
基金supported by the CAMS Innovation Fund for Medical Sciences(CIFMS,No.2023-I2M-2-009).
文摘An electronic circular dichroism(ECD)-based chiroptical sensing method has been developed forβ-andγ-chiral primary amines via a C-H activation reaction.With the addition of Pd(OAc)_(2),the flexible remote chiral primary amine fragment in the bidentate ligand intermediate was fixed to form a cyclopalladium complex,producing an intense ECD response.The correlation between the sign of Cotton effects and the absolute configuration of substrates was proposed,together with theoretical verification using timedependent density functional theory(TDDFT).Chiroptical sensing of an important drug raw material was performed to provide rapid and accurate information on the absolute optical purity.This work introduces an alternative perspective of C-H activation reaction as well as a feasible chiroptical sensing method of remote chiral amines.
基金supported by the Fundamental Research Funds for the National Natural Science Foundation of China 52225003,22208021,22109004the National Key R&D Program of China 2022YFB4101702.
文摘Although supported solid amine adsorbents have attracted great attention for CO_(2) capture,critical chemical deactivation problems including oxidative degradation and urea formation have severely restricted their practical applications for flue gas CO_(2) capture.In this work,we reveal that the nature of surface hydroxyl groups(metal hydroxyl Al–OH and nonmetal hydroxyl Si–OH)plays a key role in the deactivation mechanisms.The polyethyleneimine(PEI)supported on Al–OH-containing substrates suffers from severe oxidative degradation during the CO_(2) capture step due to the breakage of amine-support hydrogen bonding networks,but exhibits an excellent anti-urea formation feature by preventing dehydration of carbamate products under a pure CO_(2) regeneration atmosphere.In contrast,PEI supported on Si–OHcontaining substrates exhibits excellent anti-oxidative stability under simulated flue gas conditions by forming a robust hydrogen bonding protective network with Si–OH,but suffers from obvious urea formation during the pure CO_(2) regeneration step.We also reveal that the urea formation problem for PEI-SBA-15 can be avoided by the incorporation of an OH-containing PEG additive.Based on the intrinsic understanding of degradation mechanisms,we successfully synthesized an adsorbent 40PEI-20PEG-SBA-15 that demonstrates outstanding stability and retention of a high CO_(2) capacity of 2.45 mmol g^(−1) over 1000 adsorption–desorption cycles,together with negligible capacity loss during aging in simulated flue gas(10%CO_(2)+5%O_(2)+3%H_(2)O)for one month at 60–70℃.We believe this work makes great contribution to the advancement in the field of ultra-stable solid amine-based CO_(2) capture materials.
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).
基金financial support from Business Finland 8205/31/2022the Magnus Ehrnrooth Foundation for financial support.
文摘Point source CO_(2) capture(PSCC)is crucial for decarbonizing various industrial sectors,while direct air capture(DAC)holds promise for removing CO_(2) directly from the air.Sorbents play a critical role in both technologies,with their performances,efficiency,cost,etc.,largely depending on which type is used(physical or chemical).Solid amine sorbents(SAS)employed in the chemical adsorption of CO_(2) are suitable for both PSCC and DAC.SAS offer significant advantages over liquid amines such as monoethanolamine(MEA),due to their ability to perform cyclic adsorption–desorption with much lower energy requirement.The environmental concern associated with MEA can be mitigated by SAS.Support materials have a significantly important role in stabilizing amine and enhancing stability and kinetics;varieties of support materials have been screened at a laboratory scale.One promising support material is a silica gel(SG),which is commercially available and attractive for designing cost-effective sorbents for large-scale CO_(2) capture.Various impregnation methods such as physical adsorption and covalent functionalization have been employed to functionalize silica surfaces with amines.This review provided a comprehensive critical analysis of SG-based SAS for CO_(2) capture.We discussed and evaluated them in terms of their adsorption capacity,adsorption,and desorption conditions,and the kinetics involved in these processes.Finally,we proposed a few recommendations for further development of low-cost,lower carbon footprint SAS for large-scale deployment of CO_(2) capture technology.
