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
Octopamine regulates the function of many tissues and physiological processes in invertebrates. The expression of octopamine receptor genes has been examined in multiple tissue types in several different insect orders...Octopamine regulates the function of many tissues and physiological processes in invertebrates. The expression of octopamine receptor genes has been examined in multiple tissue types in several different insect orders. However, little work has addressed this issue in Coleoptera. Most studies characterize individual genes in different tissue types, but here we describe the expression of 6 octopamine receptor genes in thoracic musculature, oviducts, Malpighian tubules, and fat body of female Nicrophorus vespilloides beetles to characterize both different genes and different tissues within a single study. We then compare the gene expression profiles found in this beetle to other insects to examine the extent to which expression profiles are conserved across insects. We also examine the relative involvement of octopamine verses octopamine/tyramine receptors based on receptor gene expression in each tissue to help elucidate if tyramine plays a role in the regulation of these tissues. We find a high degree of overlap in the expression profile of the 6 genes examined in the thoracic muscula^tre, a moderate amount for the oviducts, and divergent profiles for Malpighian tubules and fat body. Based on expression difference in receptor subtypes, our results also support the suggestion that tyramine is a biogenic amine with physiological actions separate from octopamine.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
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
Chronic obstructive pulmonary disease(COPD)has garnered increased attention as a result of its persistent symptoms,which undermine patientsʼquality of life.Fudosteine has substantial advantages in the treatment of COP...Chronic obstructive pulmonary disease(COPD)has garnered increased attention as a result of its persistent symptoms,which undermine patientsʼquality of life.Fudosteine has substantial advantages in the treatment of COPD due to its high efficacy and low adverse effects.In this study,Fudosteine sulfonamide derivatives Series I and amine derivatives Series II were designed and synthesized,and their biological activities were evaluated.The results showed that compound 6f had outstanding anti-inflammatory action with an IC_(50) of 1.08 mmol/L,and a higher antioxidant capacity than the lead molecule.At the same time,molecular docking investigations have revealed that compound 6f establishes hydrogen bonds and hydrophobic contacts with the MUC5AC protein.Furthermore,derivative 1f inhibited PDE4A1 enzyme activity five times more than Fudosteine.2,2-Diphenyl-1-picrylhydrazyl(DPPH)free radical scavenging tests demonstrated that all examined substances had higher antioxidant activity than Fudosteine.This study established a solid foundation for further research into COPD drug therapy.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
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
A[3+4]annulation of α-substituted allenes and Schiff bases is reported.This methodology serves as a conduit for the construction of a series of biologically important benzazepine derivatives in good to excellent yiel...A[3+4]annulation of α-substituted allenes and Schiff bases is reported.This methodology serves as a conduit for the construction of a series of biologically important benzazepine derivatives in good to excellent yields under mild conditions by an unprecedented mode involving β’-carbon of α-substituted allenes and the proposed mechanism is supported by capturing the intermediate.Moreover,this class of benzazepine derivatives exhibited potential ability of cytotoxicity toward cancer cells.展开更多
In contrast to the conventional spermiogram, metabolomics approaches give insights into the molecular composition of semen and mayprovide more detailed information on the fertility status of the respective donor. Give...In contrast to the conventional spermiogram, metabolomics approaches give insights into the molecular composition of semen and mayprovide more detailed information on the fertility status of the respective donor. Given the intra-individual variability of spermiogramparameters between two donations, this study sought to elucidate the biological variability of the seminal plasma metabolome overan average period of 8 weeks. Two time-shifted semen samples from 15 healthy donors were compared by a targeted metabolomicsapproach utilizing the Biocrates AbsoluteIDQ p180 kit. Next to intraclass correlation coefficients (ICC), which represent a measureof reliability, coefficients of variation within individuals(CVW) and coefficients of variation between individuals (CVB) were calculatedfor each metabolite to demonstrate its stability. Furthermore, men were divided into two cohorts, a similar sperm concentration(SSC) and a differing sperm concentration (DSC) cohort, based on the observed variance in sperm concentration between the twosemen donations. The ICC was higher in the SSC compared to the DSC cohort. The levels of 18 metabolites, primarily acylcarnitines,varied between the initial and subsequent donations. After subdivision into subgroups, only ornithine and phosphatidylcholine 40:5exhibited differential levels between the two donations in the SSC group, compared to 14 metabolites in the DSCgroup.CVBwashigher than CVW but both differed between the metabolite subclasses. Biogenic amines were identified as the least reliable analytesover time, exhibiting the highest CVW,compared to sphingomyelins, which demonstrated the highest reliability with the lowestvariation.CVB was the highest for ether-bound glycerophosphatidylcholines and the lowest for amino acids.展开更多
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
[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
Iron-nitrogen-carbon(Fe-N-C)materials with Fe-N_(4)structures have been considered as the most promising alternatives of scarce and precious platinum(Pt)for oxygen reduction reaction.Particularly,the hightemperature p...Iron-nitrogen-carbon(Fe-N-C)materials with Fe-N_(4)structures have been considered as the most promising alternatives of scarce and precious platinum(Pt)for oxygen reduction reaction.Particularly,the hightemperature pyrolysis of a precursor mixture of N-containing amine polymers,Fe salts,and carbon supports,has become a popular method for the synthesis of high-performance Fe-N-C catalysts.The oxidative polymerization of amine monomers can usually proceed under acidic conditions,however,the acidcaused protonation of N-groups is not conducive to their coordination with Fe ions for the formation of high-density Fe-N_(4)sites.Here,we propose a protonation elimination strategy of soaking the polymerization products in alkaline solutions to increase Fe-N_(4)active sites.Theoretical calculations display that the Gibbs free energy change values of binding reactions between Fe ions and N-groups are-3.70 and-26.99 kcal/mol at p H 0 and 7,respectively,suggesting that the deprotonation can facilitate the Fe-N coordination.There is a two-fold increase in the number of Fe-N_(4)active sites for final Fe-N-C catalyst which exhibits significantly enhanced ORR activity and excellent Zn-air battery performance.This deprotonation effect can be applied to different amine compounds and transition-metal ions as a universal strategy for the development of preeminent non-precious metal carbon catalysts.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
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.
文摘Octopamine regulates the function of many tissues and physiological processes in invertebrates. The expression of octopamine receptor genes has been examined in multiple tissue types in several different insect orders. However, little work has addressed this issue in Coleoptera. Most studies characterize individual genes in different tissue types, but here we describe the expression of 6 octopamine receptor genes in thoracic musculature, oviducts, Malpighian tubules, and fat body of female Nicrophorus vespilloides beetles to characterize both different genes and different tissues within a single study. We then compare the gene expression profiles found in this beetle to other insects to examine the extent to which expression profiles are conserved across insects. We also examine the relative involvement of octopamine verses octopamine/tyramine receptors based on receptor gene expression in each tissue to help elucidate if tyramine plays a role in the regulation of these tissues. We find a high degree of overlap in the expression profile of the 6 genes examined in the thoracic muscula^tre, a moderate amount for the oviducts, and divergent profiles for Malpighian tubules and fat body. Based on expression difference in receptor subtypes, our results also support the suggestion that tyramine is a biogenic amine with physiological actions separate from octopamine.
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 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.
文摘Chronic obstructive pulmonary disease(COPD)has garnered increased attention as a result of its persistent symptoms,which undermine patientsʼquality of life.Fudosteine has substantial advantages in the treatment of COPD due to its high efficacy and low adverse effects.In this study,Fudosteine sulfonamide derivatives Series I and amine derivatives Series II were designed and synthesized,and their biological activities were evaluated.The results showed that compound 6f had outstanding anti-inflammatory action with an IC_(50) of 1.08 mmol/L,and a higher antioxidant capacity than the lead molecule.At the same time,molecular docking investigations have revealed that compound 6f establishes hydrogen bonds and hydrophobic contacts with the MUC5AC protein.Furthermore,derivative 1f inhibited PDE4A1 enzyme activity five times more than Fudosteine.2,2-Diphenyl-1-picrylhydrazyl(DPPH)free radical scavenging tests demonstrated that all examined substances had higher antioxidant activity than Fudosteine.This study established a solid foundation for further research into COPD drug therapy.
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.
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financially supported by the National Natural Science Foundation of China(No.21572271).
文摘A[3+4]annulation of α-substituted allenes and Schiff bases is reported.This methodology serves as a conduit for the construction of a series of biologically important benzazepine derivatives in good to excellent yields under mild conditions by an unprecedented mode involving β’-carbon of α-substituted allenes and the proposed mechanism is supported by capturing the intermediate.Moreover,this class of benzazepine derivatives exhibited potential ability of cytotoxicity toward cancer cells.
文摘In contrast to the conventional spermiogram, metabolomics approaches give insights into the molecular composition of semen and mayprovide more detailed information on the fertility status of the respective donor. Given the intra-individual variability of spermiogramparameters between two donations, this study sought to elucidate the biological variability of the seminal plasma metabolome overan average period of 8 weeks. Two time-shifted semen samples from 15 healthy donors were compared by a targeted metabolomicsapproach utilizing the Biocrates AbsoluteIDQ p180 kit. Next to intraclass correlation coefficients (ICC), which represent a measureof reliability, coefficients of variation within individuals(CVW) and coefficients of variation between individuals (CVB) were calculatedfor each metabolite to demonstrate its stability. Furthermore, men were divided into two cohorts, a similar sperm concentration(SSC) and a differing sperm concentration (DSC) cohort, based on the observed variance in sperm concentration between the twosemen donations. The ICC was higher in the SSC compared to the DSC cohort. The levels of 18 metabolites, primarily acylcarnitines,varied between the initial and subsequent donations. After subdivision into subgroups, only ornithine and phosphatidylcholine 40:5exhibited differential levels between the two donations in the SSC group, compared to 14 metabolites in the DSCgroup.CVBwashigher than CVW but both differed between the metabolite subclasses. Biogenic amines were identified as the least reliable analytesover time, exhibiting the highest CVW,compared to sphingomyelins, which demonstrated the highest reliability with the lowestvariation.CVB was the highest for ether-bound glycerophosphatidylcholines and the lowest for amino acids.
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.
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sponsored by the National Natural Science Foundation of China(No.22272105)the Natural Science Foundation of Shanghai(No.23ZR1423900)。
文摘Iron-nitrogen-carbon(Fe-N-C)materials with Fe-N_(4)structures have been considered as the most promising alternatives of scarce and precious platinum(Pt)for oxygen reduction reaction.Particularly,the hightemperature pyrolysis of a precursor mixture of N-containing amine polymers,Fe salts,and carbon supports,has become a popular method for the synthesis of high-performance Fe-N-C catalysts.The oxidative polymerization of amine monomers can usually proceed under acidic conditions,however,the acidcaused protonation of N-groups is not conducive to their coordination with Fe ions for the formation of high-density Fe-N_(4)sites.Here,we propose a protonation elimination strategy of soaking the polymerization products in alkaline solutions to increase Fe-N_(4)active sites.Theoretical calculations display that the Gibbs free energy change values of binding reactions between Fe ions and N-groups are-3.70 and-26.99 kcal/mol at p H 0 and 7,respectively,suggesting that the deprotonation can facilitate the Fe-N coordination.There is a two-fold increase in the number of Fe-N_(4)active sites for final Fe-N-C catalyst which exhibits significantly enhanced ORR activity and excellent Zn-air battery performance.This deprotonation effect can be applied to different amine compounds and transition-metal ions as a universal strategy for the development of preeminent non-precious metal carbon catalysts.
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.
