The development of general and practical strategies toward the construction of medium-sized rings is still challenging in organic synthesis,especially for the multiple stereocenters control of substituted groups on th...The development of general and practical strategies toward the construction of medium-sized rings is still challenging in organic synthesis,especially for the multiple stereocenters control of substituted groups on the ring owing to the long distance between groups.Thus,stereoselective synthesis of multi-substituted ten-membered rings is attractive.Herein,a rapid assembly of various highly substituted ten-membered nitrogen heterocycles between two 1,3-dipoles through a tandem[3+3]cycloaddition/aza-Claisen rearrangement of N-vinyl-α,β-unsaturated nitrones and aza-oxyallyl or oxyallyl cations are disclosed.Products containing two or multiple stereocenters could be obtained in up to 96%yield with high regioselectivity and diastereoselectivity.Selective N-O bond cleavages of ten-membered nitrogen heterocycles lead to various novel 5,6,6-perifused benzofurans,bicyclo[4.4.0]or bicyclo[5.3.0]skeletons containing three or multiple continuous stereocenters in good yields and high diastereoselectivity.Biological tests show that the obtained ten-membered N-heterocycles and bicyclo[4.4.0]skeletons inhibited nitric oxide generation in LPS-stimulated RAW264.7 cells and might serve as good anti-inflammatory agents.展开更多
The selective hydrogenation of quinolines to 1,2,3,4-tetrahydroquinolines(py-THQ) and its derivatives has attracted a considerable amount of attention as they show great versatility in many pharmaceuticals, agrochemic...The selective hydrogenation of quinolines to 1,2,3,4-tetrahydroquinolines(py-THQ) and its derivatives has attracted a considerable amount of attention as they show great versatility in many pharmaceuticals, agrochemicals, and fine chemicals. Over the past few decades, great breakthroughs have been achieved in the controlled synthesis of efficient heterogeneous catalysts used for the selective hydrogenation of functionalized quinoline compounds, which allow one to correlate the structure-property relationships. In this review, we will summarize the recent significant progress achieved in this field covering the synthetic strategies, microstructural and chemical features, catalytic performance, and internal relationships. State-of-the-art noble metal-based single(Pd, Pt, Ru, Rh, Ir and Au) and bi/multi-metallic catalysts(RuCu, AuPd, and PdNi) are first introduced, followed by a summary of earth-abundant metal-based catalysts(Co, Fe, Ni, and Cu). Finally, the dehydrogenation of N-heterocycles is introduced to form a reversible hydrogenation/dehydrogenation system for H2 storage, which can be employed in a liquid organic hydrogen system. Furthermore, the reaction mechanism and future research direction in these areas are also discussed. This review will deepen our understanding of the catalytic transformation of N-heterocycles and provide guidance for researchers on the rational design of catalysts.展开更多
The development of covalent organic frameworks(COFs)with robust linkages is fundamentally important for the photocatalytic production of H_(2)O_(2).In this work,a series of isostructural COFs with robust imidazole lin...The development of covalent organic frameworks(COFs)with robust linkages is fundamentally important for the photocatalytic production of H_(2)O_(2).In this work,a series of isostructural COFs with robust imidazole linkage were synthesized as photocatalysts for H_(2)O_(2)production via the precise N-substituted microenvironment regulation(benzene,pyridine,pyrimidine,and triazine).The corresponding frameworks enable water and dissolved oxygen to reach the catalytic sites easily via planar skeletons and regulation of nitrogen-atom numbers.Additionally,the N-adjustment of heterocycle units in these COFs could significantly regulate the electronic band structures,light-harvesting capacity,and hydrophilic properties.The experimental investigation demonstrated that the photocatalytic process of COFs was composed of a dominant and indirect two-electron(2e^(-))oxygen reduction reaction(ORR).Notably,compared to H-COF(benzene),P-COF(pyridine),and M-COF(pyrimidine),T-COF with triazine unit exhibited the highest H_(2)O_(2)production rate of 42,180μmol·g^(-1)·h^(-1)due to its wider visible light absorption and higher separation efficiency of photogenerated electron-hole pairs.Theoretical investigations confirmed that N-heterocycle units in COFs could precisely modulate the energy barrier related to the formation of*OOH and*O_(2-).This study is expected to provide a new way for rationally designing imidazole-linked COFs as promising photocatalysts for efficiently photocatalytic H_(2)O_(2)generation.展开更多
The development of an efficient and sustainable synthetic route for formaldehyde production from renewable feedstock,especially in combination with a subsequent transformation to straightforwardly construct valuable c...The development of an efficient and sustainable synthetic route for formaldehyde production from renewable feedstock,especially in combination with a subsequent transformation to straightforwardly construct valuable chemicals,is highly desirable.Herein,we report a novel manganese-catalyzed dehydrogenative cyclization of methanol as a formaldehyde surrogate with a variety of dinucleophiles for facile synthesis of N-heterocycles.The in situ generated formaldehyde via catalytic methanol dehydrogenation can be selectively trapped by diverse dinucleophiles to avoid several possible side reactions.The utilty of this transformation is further highlighted by its successful appliation to the synthesis of 13C-labeled N-heterocycles using 13CH_(3)OH as a readily accessible 13C-isotope reagent.展开更多
The aqueous zinc-organic battery is a promising candidate for large-scale energy storage.However,the rational design of advanced organic cathodes with high capacity,long lifespan,and high rate capability remains a big...The aqueous zinc-organic battery is a promising candidate for large-scale energy storage.However,the rational design of advanced organic cathodes with high capacity,long lifespan,and high rate capability remains a big challenge.Herein,we propose that extending theπ-conjugation by N-heterocycles can provide more active sites,lead to insolubility,and facilitate charge transfer,thus boosting the overall electrochemical performance of organic electrodes.Based on this concept,a novel organic compound,dipyrido[3ʹ,2ʹ:5,6;2″,3″:7,8]quinoxalino[2,3-i]dipyrido[3,2-a:2ʹ,3ʹ-c]phenazine-10,21-dione(DQDPD),has been rationally designed and evaluated as the cathode for aqueous zinc batteries.Excitingly,DQDPD shows a record high capacity(509 mAh g^(−1) at 0.1 A g^(−1),corresponding to a record-breaking energy density of 348 Wh kg^(−1)),excellent cycling stability(92%capacity retention after 7500 cycles at 10 A g^(−1)),and fast-charging capability(161 mAh g^(−1) at 20 A g^(−1)).Our work offers new ideas in the molecular engineering of organic electrodes for high-performance rechargeable batteries.展开更多
Catalytic amination of alkenes is one of the most attractive reactions for the construction of complex heterocycles with nitrogen centers. Herein, we present that synergistic photoredox and cobaloxime catalysis allows...Catalytic amination of alkenes is one of the most attractive reactions for the construction of complex heterocycles with nitrogen centers. Herein, we present that synergistic photoredox and cobaloxime catalysis allows for highly efficient and mild dehydrogenative reactions between various NH nucleophiles and di-, tri-, and tetrasubstituted alkenes in the absence of external oxidants, thus enabling access to an array of N-heterocycles. Notably, both Z-and E-alkene-containing N-heterocycles are accessible. Mechanistic studies indicated that the Z-cinnamyl derivatives could be generated by photocatalytic E to Z alkene isomerization through an energy transfer process. Moreover, we find that sluggish energy transfer could inhibit the E to Z alkene isomerization process, thus offering the cinnamyl derivatives with E-selectivity. Our results highlight the benefits of the reactions using dual photoredox and cobaloxime catalysis to lead to diverse N-heterocycles.展开更多
Fused polycyclic N-heterocycles are very important scaffolds in biomedicinal chemistry and materials science.Intramolecular alkyne hydroamination is a powerful method for the construction of N-heterocycles.In the last...Fused polycyclic N-heterocycles are very important scaffolds in biomedicinal chemistry and materials science.Intramolecular alkyne hydroamination is a powerful method for the construction of N-heterocycles.In the last two decades,copper-catalyzed domino reactions based on intramolecular alkyne hydroamination has emerged as a robust strategy for assembling various fused polycyclic N-heterocycles.Great progress has been achieved in this area.This short review covers the advances made in copper-catalyzed domino synthesis of fused polycyclic N-heterocycles based on the strategy from 2008 to 2023,and will hopefully serve as an inspiration towards the exploration of new copper-catalyzed versions of the transformation.The domino transformations are introduced and discussed from five aspects according to the different key processes involved in these reactions.展开更多
The production of high-valued organonitrogen chemicals,especially N-heterocycles,requires artificial N_(2)fixation accompanied by the consumption of fossil resources.To avoid the use of these energy-and resource-inten...The production of high-valued organonitrogen chemicals,especially N-heterocycles,requires artificial N_(2)fixation accompanied by the consumption of fossil resources.To avoid the use of these energy-and resource-intensive processes,we develop a sustainable strategy to convert nitrogen-rich animal biomass into N-heterocycles through a thermochemical conversion process(TCP)under atmospheric pressure.A high percentage of N-heterocycles(87.51%)were obtained after the TCP of bovine skin due to the abundance of nitrogen-containing amino acids(e.g.,glycine,proline,and L-hydroxyproline).Animal biomass with more diverse amino acid composition(e.g.,muscles)yielded higher concentrations of amines/amides and nitriles after TCP.In addition,by introducing catalysts(KOH for pyrrole and Al_(2)O_(3)for cyclo-Gly-Pro)to TCP,the production quantities of pyrrole and cyclo-Gly-Pro increased to 30.79 mg g^(-1)and 38.88 mg g^(-1),respectively.This approach can be used to convert the significant animal biomass waste generated annually from animal culls into valued organonitrogen chemicals while circumventing NH3-dependent and petro-chemical-dependent synthesis routes.展开更多
Synthetic N-heterocyclic compounds,such as quinoxalines,have shown a crucial role in pharmaceutical as well as food and dye industries.However,the traditional synthesis toward N-heterocycles relies on multistep energy...Synthetic N-heterocyclic compounds,such as quinoxalines,have shown a crucial role in pharmaceutical as well as food and dye industries.However,the traditional synthesis toward N-heterocycles relies on multistep energy and costintensive non-sustainable processes.Here,we report a facile approach that allows one-step conversion of biomass-derived carbohydrates to valuable quinoxalines in the presence of aryl-1,2-diamines in water without any harmful metal catalysts/organic solvents via spontaneously engineering involved cascade reactions under hydrothermal conditions.Aryl-1,2-diamines are revealed as the key to propel this transformation through boosting carbohydrate fragmentation into small 1,2-dicarbonyl intermediates and subsequently trapping them for constituting stable quinoxaline scaffolds therefore avoiding a myriad of undesired side reactions.The tunability of product selectivity can be also achievable by adjusting the basicity of the reaction environment.Both batch and continuous-flow integrated processes were verified for production of quinoxalines in an exceptionally eco-benign manner(E-factor<1),showing superior sustainability and economic viability.展开更多
Chiral benzo-fused N-heterocycles are frequently found in natural and synthetic products.However,their synthesis usually suffers from different limitations such as difficulty in accessing appropriate starting material...Chiral benzo-fused N-heterocycles are frequently found in natural and synthetic products.However,their synthesis usually suffers from different limitations such as difficulty in accessing appropriate starting materials and unsatisfactory stereoselectivities.In this work,an unprecedented chiral sulfide-catalyzed enantioselective Friedel-Crafts-type electrophilic chlorination is shown to construct various 3,4-functionalized tetrahydroquinolines with excellent enantio-and diastereoselectivities from readily available aniline derivatives.Interestingly,employing N-allyl 1-naphthanilides as substrates,divergent reactions via chlorocarbocyclization and dearomatization occurred to afford two chiral polycyclic benzo-fused N-heterocycles.The system that we developed extends the scope of asymmetric chlorination to general substrateswithout the need of a N-H group,and significantly promotes the synthesis of enantioenriched benzo-fused N-heterocycles.展开更多
The first efficiently N-heterocyclic carbene-catalyzed[4+2]cycloaddition of salicylaldehydes and pyrazole-4,5-diones to directly synthesis of spiro-ketal-pyrazolones bearing both oxygens of the ketal unit in the same ...The first efficiently N-heterocyclic carbene-catalyzed[4+2]cycloaddition of salicylaldehydes and pyrazole-4,5-diones to directly synthesis of spiro-ketal-pyrazolones bearing both oxygens of the ketal unit in the same ring was disclosed.This reaction was qualified with broad substrate scope,achieving moderate to excellent yield(up to 98%).This method has mild reaction conditions and simple operation,providing a new attractive strategy for the practical syntheses of multifunctionalized spiroketals including pyrazolone structures with mild reaction condition and operational simplicity.Furthermore,the gram scale and derivative transformations have also been achieved.展开更多
Atropisomeric phosphines are crucial for asymmetric catalysis but remain synthetically challenging.Herein,an N-heterocyclic carbene(NHC)catalyzed esterification reaction of dialdehydes with arylboronic acids was devel...Atropisomeric phosphines are crucial for asymmetric catalysis but remain synthetically challenging.Herein,an N-heterocyclic carbene(NHC)catalyzed esterification reaction of dialdehydes with arylboronic acids was developed,successfully constructing the framework of axially chiral phosphorus compounds.Mechanistic studies have revealed that the reaction initially undergoes a desymmetrization process,followed by a kinetic resolution pathway,affording a series of axially chiral phosphorus compounds with high enantioselectivity(up to 92%ee).展开更多
An unprecedented 2,3-arylacylation reaction of allenes with aryl iodides and aldehydes was developed by resorting to Pd/NHC synergetic catalysis.It is the first time that allene was introduced into transition metal an...An unprecedented 2,3-arylacylation reaction of allenes with aryl iodides and aldehydes was developed by resorting to Pd/NHC synergetic catalysis.It is the first time that allene was introduced into transition metal and NHC synergetic catalysis,which demonstrated a versatile three-component reaction pattern,thus enabling two C-C bonds forged regioselectively in the reaction.The important reaction intermediates were successfully captured and characterized by HRMS analysis,and the migrative insertion of allene to the Ph-Pd species was identified as the reaction rate-limiting step by kinetic experiments.展开更多
The precise control over the hierarchical self-assembly of sophisticated structures with comparable complexities and functions relying on the modulation of basic building blocks is elusive and highly desirable.Here,we...The precise control over the hierarchical self-assembly of sophisticated structures with comparable complexities and functions relying on the modulation of basic building blocks is elusive and highly desirable.Here,we report a fluorinated N-heterocyclic carbene(NHC)–based pillarplex with a tunable quaternary structure,employed as an efficient building block for constructing hierarchical superstructures.Initially,multiple noncovalent interactions in the NHC-based pillarplex,particularly those between the fluorinated pillarplex and PF_(6)-anions,induce the formation of a supramolecular gel at high concentrations.Additionally,this hierarchical self-assembled structure can be regulated by adjusting anion types,facilitating the controlled transformation from a supramolecular gel into a supramolecular channel upon the introduction of four monocarboxylic acids as anions.The study provides insight into the construction and controlled regulation of superstructures based on NHC-based pillarplexes.展开更多
Lignin is the only largest renewable aromatic resource in nature.Currently,most lignin is underutilized for low-value applications due to the complex structure and recalcitrant chemical properties.Over the past decade...Lignin is the only largest renewable aromatic resource in nature.Currently,most lignin is underutilized for low-value applications due to the complex structure and recalcitrant chemical properties.Over the past decades,extensive research has been devoted to valorizing lignin into aromatic N-heterocycles in the presence of nitrogen sources.It overcomes the element limitation,expands the products portfolio and would play a momentous role in value-added biorefinery concept.In this review,the latest research progress in the synthesis of N-heterocyclic compounds from lignin,lignin model compounds,and lignin-derived monomers(phenols,aromatic alcohols,aldehydes,ketones,and ethers)is presented.According to the structural characteristics of the products,these achievements are classified by the construction of five-,six-,and seven-membered N-heterocyclic compounds through one-step,multi-step,or one-pot multi-step reactions.Furthermore,the tailor-designed routes and catalytic systems,along with the reaction mechanisms/pathways involved are entirely discussed to elucidate the challenges regarding the structural complexity of lignin,the incompatible catalysis for C–O cleavage and C–N formation,as well as the nitrogen-heterocyclic ring construction.The prospects,future research efforts and process developments for the refining of lignin into aromatic N-heterocyclic compounds are outlined in terms of economy,environmental friendliness,and safety so as to draw some guidelines for lignin valorization.展开更多
The N-heterocyclic carbene(NHC)-catalyzed reactions involving two-electron reaction pathway have been well-established.However,the development of NHC-catalyzed radical reactions is still in its infancy in terms of rea...The N-heterocyclic carbene(NHC)-catalyzed reactions involving two-electron reaction pathway have been well-established.However,the development of NHC-catalyzed radical reactions is still in its infancy in terms of reaction types and enantioselectivity.In the past decade,several elegant NHC-catalyzed radical reactions have been developed,including NHC-catalyzed oxidation of aldehydes to esters,reductive coupling reactions using Breslow intermediate as SET reductant and NHC-catalyzed reactions via radical homoenolates,dienoaltes and trienolates.This review summarizes the recent advances in NHC-catalyzed reactions involving radical intermediates.展开更多
Electrocatalytic nitrogen reduction reaction(NRR)at ambient conditions holds great promise for sustainably synthesizing ammonia(NH3),while developing highly-efficient,long-term stable,and inexpensive catalysts to acti...Electrocatalytic nitrogen reduction reaction(NRR)at ambient conditions holds great promise for sustainably synthesizing ammonia(NH3),while developing highly-efficient,long-term stable,and inexpensive catalysts to activate the inert N≡N bond is a key scientific issue.In this work,on the basis of the concept"N-heterocyclic carbenes(NHCs)",we propose a carbon decorated graphitic-carbon nitride(C/g-C3N4)as novel metal-free NRR electrocatalyst by means of density functional theory(DFT)computations.Our results reveal that the introduced C atom in g-C3N4 surface can be regarded as NHCs and catalytic sites for activating N≡N bond,and are stabilized by the g-C3N4 substrate due to sterically disfavored dimerization.Especially,this NHCs-based heterogeneous catalysis can efficiently reduce the activated N2 molecule to NH3 with a low overpotential of 0.05 V via an enzymatic mechanism.Our work is the first report of NHCs-based electrocatalyst for N2 fixation,thus opening an alternative avenue for advancing sustainable NH3 production.展开更多
Despite the extraordinary success has been achieved in metal catalyst-promoted stereoselective ring-opening polymerization（ROP） of rac-lactide（rac-LA）, well-controlled stereoselective rac-LA ROP by organic catalys...Despite the extraordinary success has been achieved in metal catalyst-promoted stereoselective ring-opening polymerization（ROP） of rac-lactide（rac-LA）, well-controlled stereoselective rac-LA ROP by organic catalyst still remains a scientific challenge. Here we report our investigations into organocatalytic stereoselective ROP of rac-LA by utilizing novel bulky chiral and achiral N-heterocyclic carbenes（NHC）, 1,3-bis-（1′-naphthylethyl）imidazolin-2-ylidene. The effect of polymerization conditions（e.g. solvent, temperature, alcohol initiator） on ROP behavior by these bulky NHCs has been fully studied, leading to the formation of isotactic-rich stereoblock polylactide（Pi = 0.81） under optimized conditions with high activity（Conv. = 98% in 30 min） and narrow molecular weight dispersity（D = 1.05）.展开更多
Intermolecular Stetter reaction of aromatic aldehydes with（E）-（2-nitrovinyl）cyclohexane catalyzed by thiazolium A has been developed.The reaction rate and efficiency are profoundly impacted by the presence of thio...Intermolecular Stetter reaction of aromatic aldehydes with（E）-（2-nitrovinyl）cyclohexane catalyzed by thiazolium A has been developed.The reaction rate and efficiency are profoundly impacted by the presence of thiourea B.The reaction affords moderate to good yields of the Stetter product.Some factors influencing yield were discussed.展开更多
A new methodology for the synthesis of a green plasticizer acetyltributylcitrate through a transesterification reaction was developed. Under the catalysis of alkyl-substituted imidazol-type N-heterocyclic carbenes, tr...A new methodology for the synthesis of a green plasticizer acetyltributylcitrate through a transesterification reaction was developed. Under the catalysis of alkyl-substituted imidazol-type N-heterocyclic carbenes, tributyl citrate can react with vinyl acetate smoothly to give ATBC in high yield.展开更多
基金the National Natural Science Foundation of China(No.22071035)the Natural Science Foundation of Guangxi(Nos.2023GXNSFDA026025,2022GXNSFBA035494)+2 种基金Guangxi Minzu University Scientific Research Funds for Talent Introduction(2022KJQD14)the Student Innovation Training Program(No.202310602014)are greatly appreciated.
文摘The development of general and practical strategies toward the construction of medium-sized rings is still challenging in organic synthesis,especially for the multiple stereocenters control of substituted groups on the ring owing to the long distance between groups.Thus,stereoselective synthesis of multi-substituted ten-membered rings is attractive.Herein,a rapid assembly of various highly substituted ten-membered nitrogen heterocycles between two 1,3-dipoles through a tandem[3+3]cycloaddition/aza-Claisen rearrangement of N-vinyl-α,β-unsaturated nitrones and aza-oxyallyl or oxyallyl cations are disclosed.Products containing two or multiple stereocenters could be obtained in up to 96%yield with high regioselectivity and diastereoselectivity.Selective N-O bond cleavages of ten-membered nitrogen heterocycles lead to various novel 5,6,6-perifused benzofurans,bicyclo[4.4.0]or bicyclo[5.3.0]skeletons containing three or multiple continuous stereocenters in good yields and high diastereoselectivity.Biological tests show that the obtained ten-membered N-heterocycles and bicyclo[4.4.0]skeletons inhibited nitric oxide generation in LPS-stimulated RAW264.7 cells and might serve as good anti-inflammatory agents.
基金supported by the National Postdoctoral Innovative Talent Support Program(Z86101001)China Postdoctoral Science Foundation(Z741010006)Preferred Postdoctoral Research Projects Foundation of Zhejiang Province(Z87101003)~~
文摘The selective hydrogenation of quinolines to 1,2,3,4-tetrahydroquinolines(py-THQ) and its derivatives has attracted a considerable amount of attention as they show great versatility in many pharmaceuticals, agrochemicals, and fine chemicals. Over the past few decades, great breakthroughs have been achieved in the controlled synthesis of efficient heterogeneous catalysts used for the selective hydrogenation of functionalized quinoline compounds, which allow one to correlate the structure-property relationships. In this review, we will summarize the recent significant progress achieved in this field covering the synthetic strategies, microstructural and chemical features, catalytic performance, and internal relationships. State-of-the-art noble metal-based single(Pd, Pt, Ru, Rh, Ir and Au) and bi/multi-metallic catalysts(RuCu, AuPd, and PdNi) are first introduced, followed by a summary of earth-abundant metal-based catalysts(Co, Fe, Ni, and Cu). Finally, the dehydrogenation of N-heterocycles is introduced to form a reversible hydrogenation/dehydrogenation system for H2 storage, which can be employed in a liquid organic hydrogen system. Furthermore, the reaction mechanism and future research direction in these areas are also discussed. This review will deepen our understanding of the catalytic transformation of N-heterocycles and provide guidance for researchers on the rational design of catalysts.
基金supported by the National Natural Science Foundation of China(Nos.U22A20143,52403288)the Natural Science Foundation of Henan Province(No.242300421073)+3 种基金the Program for Science&Technology Innovation Talents in Universities of Henan Province(No.23HASTIT015)Henan Provincial Science and Technology R&D Program Joint Fund(No.235200810071),Central Plains Elite Young Top-notch Talents,the Key Scientific and Technological Project of Henan Province(No.252102230152)Open Project Program of Yaoshan laboratory(No.2024004)Certificate of Postdoctoral Research Grant in Henan Province and Zhongyuan Institute of Technology Superior Discipline Strength Enhancement Program.
文摘The development of covalent organic frameworks(COFs)with robust linkages is fundamentally important for the photocatalytic production of H_(2)O_(2).In this work,a series of isostructural COFs with robust imidazole linkage were synthesized as photocatalysts for H_(2)O_(2)production via the precise N-substituted microenvironment regulation(benzene,pyridine,pyrimidine,and triazine).The corresponding frameworks enable water and dissolved oxygen to reach the catalytic sites easily via planar skeletons and regulation of nitrogen-atom numbers.Additionally,the N-adjustment of heterocycle units in these COFs could significantly regulate the electronic band structures,light-harvesting capacity,and hydrophilic properties.The experimental investigation demonstrated that the photocatalytic process of COFs was composed of a dominant and indirect two-electron(2e^(-))oxygen reduction reaction(ORR).Notably,compared to H-COF(benzene),P-COF(pyridine),and M-COF(pyrimidine),T-COF with triazine unit exhibited the highest H_(2)O_(2)production rate of 42,180μmol·g^(-1)·h^(-1)due to its wider visible light absorption and higher separation efficiency of photogenerated electron-hole pairs.Theoretical investigations confirmed that N-heterocycle units in COFs could precisely modulate the energy barrier related to the formation of*OOH and*O_(2-).This study is expected to provide a new way for rationally designing imidazole-linked COFs as promising photocatalysts for efficiently photocatalytic H_(2)O_(2)generation.
基金This project was supported by the National Natural Science Foundation of China(Nos.91845107 and 21822106)the Foundation of the Department of Education of Guangdong Province(2018KZDXM070 and 2021KTSCX140)。
文摘The development of an efficient and sustainable synthetic route for formaldehyde production from renewable feedstock,especially in combination with a subsequent transformation to straightforwardly construct valuable chemicals,is highly desirable.Herein,we report a novel manganese-catalyzed dehydrogenative cyclization of methanol as a formaldehyde surrogate with a variety of dinucleophiles for facile synthesis of N-heterocycles.The in situ generated formaldehyde via catalytic methanol dehydrogenation can be selectively trapped by diverse dinucleophiles to avoid several possible side reactions.The utilty of this transformation is further highlighted by its successful appliation to the synthesis of 13C-labeled N-heterocycles using 13CH_(3)OH as a readily accessible 13C-isotope reagent.
基金supported by the National Natural Science Foundation of China(grant no.52103313)the Fundamental Research Funds for the Central Universities(grant no.531118010111)the Natural Science Foundation of Hunan Province(grant no.2021JJ30094).
文摘The aqueous zinc-organic battery is a promising candidate for large-scale energy storage.However,the rational design of advanced organic cathodes with high capacity,long lifespan,and high rate capability remains a big challenge.Herein,we propose that extending theπ-conjugation by N-heterocycles can provide more active sites,lead to insolubility,and facilitate charge transfer,thus boosting the overall electrochemical performance of organic electrodes.Based on this concept,a novel organic compound,dipyrido[3ʹ,2ʹ:5,6;2″,3″:7,8]quinoxalino[2,3-i]dipyrido[3,2-a:2ʹ,3ʹ-c]phenazine-10,21-dione(DQDPD),has been rationally designed and evaluated as the cathode for aqueous zinc batteries.Excitingly,DQDPD shows a record high capacity(509 mAh g^(−1) at 0.1 A g^(−1),corresponding to a record-breaking energy density of 348 Wh kg^(−1)),excellent cycling stability(92%capacity retention after 7500 cycles at 10 A g^(−1)),and fast-charging capability(161 mAh g^(−1) at 20 A g^(−1)).Our work offers new ideas in the molecular engineering of organic electrodes for high-performance rechargeable batteries.
基金supported by the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (18KJA350001)the Priority Academic Program Development of the Jiangsu Higher Education Institutes (PAPD)。
文摘Catalytic amination of alkenes is one of the most attractive reactions for the construction of complex heterocycles with nitrogen centers. Herein, we present that synergistic photoredox and cobaloxime catalysis allows for highly efficient and mild dehydrogenative reactions between various NH nucleophiles and di-, tri-, and tetrasubstituted alkenes in the absence of external oxidants, thus enabling access to an array of N-heterocycles. Notably, both Z-and E-alkene-containing N-heterocycles are accessible. Mechanistic studies indicated that the Z-cinnamyl derivatives could be generated by photocatalytic E to Z alkene isomerization through an energy transfer process. Moreover, we find that sluggish energy transfer could inhibit the E to Z alkene isomerization process, thus offering the cinnamyl derivatives with E-selectivity. Our results highlight the benefits of the reactions using dual photoredox and cobaloxime catalysis to lead to diverse N-heterocycles.
基金financial supports from the Natural Science Foundation of Zhejiang Province(LY21B020005)the National Natural Science Foundation of China(21202152).
文摘Fused polycyclic N-heterocycles are very important scaffolds in biomedicinal chemistry and materials science.Intramolecular alkyne hydroamination is a powerful method for the construction of N-heterocycles.In the last two decades,copper-catalyzed domino reactions based on intramolecular alkyne hydroamination has emerged as a robust strategy for assembling various fused polycyclic N-heterocycles.Great progress has been achieved in this area.This short review covers the advances made in copper-catalyzed domino synthesis of fused polycyclic N-heterocycles based on the strategy from 2008 to 2023,and will hopefully serve as an inspiration towards the exploration of new copper-catalyzed versions of the transformation.The domino transformations are introduced and discussed from five aspects according to the different key processes involved in these reactions.
基金supported by the National Talents ProgramNational Natural Science Foundation of China(22178233,22108181)+3 种基金Talents Program of Sichuan ProvinceDouble First-Class University Plan of Sichuan UniversityState Key Laboratory of Polymer Materials Engineering(sklpme 2020-03-01)The Sichuan Province Postdoctoral Special Funding.
文摘The production of high-valued organonitrogen chemicals,especially N-heterocycles,requires artificial N_(2)fixation accompanied by the consumption of fossil resources.To avoid the use of these energy-and resource-intensive processes,we develop a sustainable strategy to convert nitrogen-rich animal biomass into N-heterocycles through a thermochemical conversion process(TCP)under atmospheric pressure.A high percentage of N-heterocycles(87.51%)were obtained after the TCP of bovine skin due to the abundance of nitrogen-containing amino acids(e.g.,glycine,proline,and L-hydroxyproline).Animal biomass with more diverse amino acid composition(e.g.,muscles)yielded higher concentrations of amines/amides and nitriles after TCP.In addition,by introducing catalysts(KOH for pyrrole and Al_(2)O_(3)for cyclo-Gly-Pro)to TCP,the production quantities of pyrrole and cyclo-Gly-Pro increased to 30.79 mg g^(-1)and 38.88 mg g^(-1),respectively.This approach can be used to convert the significant animal biomass waste generated annually from animal culls into valued organonitrogen chemicals while circumventing NH3-dependent and petro-chemical-dependent synthesis routes.
基金supported by the National Natural Science Foundation of China(21932006)the China Postdoctoral Science Foundation(2019M652058)
文摘Synthetic N-heterocyclic compounds,such as quinoxalines,have shown a crucial role in pharmaceutical as well as food and dye industries.However,the traditional synthesis toward N-heterocycles relies on multistep energy and costintensive non-sustainable processes.Here,we report a facile approach that allows one-step conversion of biomass-derived carbohydrates to valuable quinoxalines in the presence of aryl-1,2-diamines in water without any harmful metal catalysts/organic solvents via spontaneously engineering involved cascade reactions under hydrothermal conditions.Aryl-1,2-diamines are revealed as the key to propel this transformation through boosting carbohydrate fragmentation into small 1,2-dicarbonyl intermediates and subsequently trapping them for constituting stable quinoxaline scaffolds therefore avoiding a myriad of undesired side reactions.The tunability of product selectivity can be also achievable by adjusting the basicity of the reaction environment.Both batch and continuous-flow integrated processes were verified for production of quinoxalines in an exceptionally eco-benign manner(E-factor<1),showing superior sustainability and economic viability.
基金the National Natural Science Foundation of China(grant nos.91856109 and 21772239)the Fundamental Research Funds for the Central Universities(grant no.20lgzd21)the Leading Scientific,Technical and Innovation Talents of Guangdong Special Support Program(grant no.2019TX05Y638)for financial support.
文摘Chiral benzo-fused N-heterocycles are frequently found in natural and synthetic products.However,their synthesis usually suffers from different limitations such as difficulty in accessing appropriate starting materials and unsatisfactory stereoselectivities.In this work,an unprecedented chiral sulfide-catalyzed enantioselective Friedel-Crafts-type electrophilic chlorination is shown to construct various 3,4-functionalized tetrahydroquinolines with excellent enantio-and diastereoselectivities from readily available aniline derivatives.Interestingly,employing N-allyl 1-naphthanilides as substrates,divergent reactions via chlorocarbocyclization and dearomatization occurred to afford two chiral polycyclic benzo-fused N-heterocycles.The system that we developed extends the scope of asymmetric chlorination to general substrateswithout the need of a N-H group,and significantly promotes the synthesis of enantioenriched benzo-fused N-heterocycles.
文摘The first efficiently N-heterocyclic carbene-catalyzed[4+2]cycloaddition of salicylaldehydes and pyrazole-4,5-diones to directly synthesis of spiro-ketal-pyrazolones bearing both oxygens of the ketal unit in the same ring was disclosed.This reaction was qualified with broad substrate scope,achieving moderate to excellent yield(up to 98%).This method has mild reaction conditions and simple operation,providing a new attractive strategy for the practical syntheses of multifunctionalized spiroketals including pyrazolone structures with mild reaction condition and operational simplicity.Furthermore,the gram scale and derivative transformations have also been achieved.
基金Project supported by the Natural Science Foundation of Henan Province(Nos.232300421234,252300421726)the Leading Talents in Scientific and Technological Innovation in Shangqiu(No.SQRC202212004)the Program of Ecological Environmental Protection in the Area of Old Course of Yellow River of Shangqiu Normal University。
文摘Atropisomeric phosphines are crucial for asymmetric catalysis but remain synthetically challenging.Herein,an N-heterocyclic carbene(NHC)catalyzed esterification reaction of dialdehydes with arylboronic acids was developed,successfully constructing the framework of axially chiral phosphorus compounds.Mechanistic studies have revealed that the reaction initially undergoes a desymmetrization process,followed by a kinetic resolution pathway,affording a series of axially chiral phosphorus compounds with high enantioselectivity(up to 92%ee).
基金the National Natural Science Foundation of China(Nos.21831008,22025109,22101286)CAS Project for Young Scientists in Basic Research(No.YSBR-050)+1 种基金Beijing National Laboratory for Molecular Sciences(No.BNLMS-CXXM-201901)the State Key Laboratory of Fine Chemicals,Dalian University of Technology(No.KF2102)are gratefully acknowledged.
文摘An unprecedented 2,3-arylacylation reaction of allenes with aryl iodides and aldehydes was developed by resorting to Pd/NHC synergetic catalysis.It is the first time that allene was introduced into transition metal and NHC synergetic catalysis,which demonstrated a versatile three-component reaction pattern,thus enabling two C-C bonds forged regioselectively in the reaction.The important reaction intermediates were successfully captured and characterized by HRMS analysis,and the migrative insertion of allene to the Ph-Pd species was identified as the reaction rate-limiting step by kinetic experiments.
基金financial support from the National Natural Science Fund for Distinguished Young Scholars of China(No.22025107)Shaanxi Fundamental Science Research Project for Chemistry&Biology(No.22JHZ003)+2 种基金the Key International Scientific and Technological Cooperation and Exchange Project of Shaanxi Province(No.2023-GHZD-15)the National Youth Top-notch Talent Support Program of Chinathe FM&EM International Joint Laboratory of Northwest University。
文摘The precise control over the hierarchical self-assembly of sophisticated structures with comparable complexities and functions relying on the modulation of basic building blocks is elusive and highly desirable.Here,we report a fluorinated N-heterocyclic carbene(NHC)–based pillarplex with a tunable quaternary structure,employed as an efficient building block for constructing hierarchical superstructures.Initially,multiple noncovalent interactions in the NHC-based pillarplex,particularly those between the fluorinated pillarplex and PF_(6)-anions,induce the formation of a supramolecular gel at high concentrations.Additionally,this hierarchical self-assembled structure can be regulated by adjusting anion types,facilitating the controlled transformation from a supramolecular gel into a supramolecular channel upon the introduction of four monocarboxylic acids as anions.The study provides insight into the construction and controlled regulation of superstructures based on NHC-based pillarplexes.
文摘Lignin is the only largest renewable aromatic resource in nature.Currently,most lignin is underutilized for low-value applications due to the complex structure and recalcitrant chemical properties.Over the past decades,extensive research has been devoted to valorizing lignin into aromatic N-heterocycles in the presence of nitrogen sources.It overcomes the element limitation,expands the products portfolio and would play a momentous role in value-added biorefinery concept.In this review,the latest research progress in the synthesis of N-heterocyclic compounds from lignin,lignin model compounds,and lignin-derived monomers(phenols,aromatic alcohols,aldehydes,ketones,and ethers)is presented.According to the structural characteristics of the products,these achievements are classified by the construction of five-,six-,and seven-membered N-heterocyclic compounds through one-step,multi-step,or one-pot multi-step reactions.Furthermore,the tailor-designed routes and catalytic systems,along with the reaction mechanisms/pathways involved are entirely discussed to elucidate the challenges regarding the structural complexity of lignin,the incompatible catalysis for C–O cleavage and C–N formation,as well as the nitrogen-heterocyclic ring construction.The prospects,future research efforts and process developments for the refining of lignin into aromatic N-heterocyclic compounds are outlined in terms of economy,environmental friendliness,and safety so as to draw some guidelines for lignin valorization.
基金the financial support from the National Natural Science Foundation of China (Nos.21672216,21831008)the Beijing National Laboratory for Molecular Sciences (No. BNLMS-CXXM-202003)。
文摘The N-heterocyclic carbene(NHC)-catalyzed reactions involving two-electron reaction pathway have been well-established.However,the development of NHC-catalyzed radical reactions is still in its infancy in terms of reaction types and enantioselectivity.In the past decade,several elegant NHC-catalyzed radical reactions have been developed,including NHC-catalyzed oxidation of aldehydes to esters,reductive coupling reactions using Breslow intermediate as SET reductant and NHC-catalyzed reactions via radical homoenolates,dienoaltes and trienolates.This review summarizes the recent advances in NHC-catalyzed reactions involving radical intermediates.
基金financially supported in China by the National Natural Science Foundation of China(21103224 and 21878227)Natural Science Funds for Distinguished Young Scholar of Heilongjiang Province(No.JC2018004)+2 种基金Natural Science Foundation of Hebei Province of China(B2019202210)in USA by NSF-CREST Center for Innovation,Research and Education in Environmental Nanotechnology(CIRE2N)(Grant Number HRD-1736093)supported by the Supercomputing Center in Harbin Normal University and Lvliang。
文摘Electrocatalytic nitrogen reduction reaction(NRR)at ambient conditions holds great promise for sustainably synthesizing ammonia(NH3),while developing highly-efficient,long-term stable,and inexpensive catalysts to activate the inert N≡N bond is a key scientific issue.In this work,on the basis of the concept"N-heterocyclic carbenes(NHCs)",we propose a carbon decorated graphitic-carbon nitride(C/g-C3N4)as novel metal-free NRR electrocatalyst by means of density functional theory(DFT)computations.Our results reveal that the introduced C atom in g-C3N4 surface can be regarded as NHCs and catalytic sites for activating N≡N bond,and are stabilized by the g-C3N4 substrate due to sterically disfavored dimerization.Especially,this NHCs-based heterogeneous catalysis can efficiently reduce the activated N2 molecule to NH3 with a low overpotential of 0.05 V via an enzymatic mechanism.Our work is the first report of NHCs-based electrocatalyst for N2 fixation,thus opening an alternative avenue for advancing sustainable NH3 production.
基金financially supported by the Science and Technology Commission of Shanghai Municipality(No.17JC1401200)
文摘Despite the extraordinary success has been achieved in metal catalyst-promoted stereoselective ring-opening polymerization（ROP） of rac-lactide（rac-LA）, well-controlled stereoselective rac-LA ROP by organic catalyst still remains a scientific challenge. Here we report our investigations into organocatalytic stereoselective ROP of rac-LA by utilizing novel bulky chiral and achiral N-heterocyclic carbenes（NHC）, 1,3-bis-（1′-naphthylethyl）imidazolin-2-ylidene. The effect of polymerization conditions（e.g. solvent, temperature, alcohol initiator） on ROP behavior by these bulky NHCs has been fully studied, leading to the formation of isotactic-rich stereoblock polylactide（Pi = 0.81） under optimized conditions with high activity（Conv. = 98% in 30 min） and narrow molecular weight dispersity（D = 1.05）.
基金supported by the Prospective Research Funds of Jiangsu Provincial Department of Science and Technology (No. BY2015049-02)the Open-end Funds of Jiangsu Key Laboratory of Marine Biotechnology, Huaihai Institute of Technology, (No. 2014HS005)the Funds of Technology Research of Lianyungang (No. CG1301)
文摘Intermolecular Stetter reaction of aromatic aldehydes with（E）-（2-nitrovinyl）cyclohexane catalyzed by thiazolium A has been developed.The reaction rate and efficiency are profoundly impacted by the presence of thiourea B.The reaction affords moderate to good yields of the Stetter product.Some factors influencing yield were discussed.
基金financial support of the Doctor Foundation of Bingtuan(No.2011BB011)and Shihezi University
文摘A new methodology for the synthesis of a green plasticizer acetyltributylcitrate through a transesterification reaction was developed. Under the catalysis of alkyl-substituted imidazol-type N-heterocyclic carbenes, tributyl citrate can react with vinyl acetate smoothly to give ATBC in high yield.
