A novel protocol for the preparation of highly functionalized 2-azabicyclo[3.3.1]nonane(morphan)derivatives via a multicomponent cascade reaction,involving 3-formylchromones,2-naphthols,and enaminones in the ionic liq...A novel protocol for the preparation of highly functionalized 2-azabicyclo[3.3.1]nonane(morphan)derivatives via a multicomponent cascade reaction,involving 3-formylchromones,2-naphthols,and enaminones in the ionic liquid[BMIM]PF6 as the solvent and promoted by 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU),was developed,which involved the cleavage of one C–O bond and formation of four bonds(1 C–O,1 C–N,and 2 C–C bonds).As a result,a series of morphan derivatives were produced through a cascade reaction,including a sequence of 1,2-addition,enol-keto tautomerization,Michael addition,dehydration,another Michael addition,imine-enamine tautomerization,and N-alkylation reactions,which were accompanied by a ring-opening reaction.This protocol was suitable for combinatorial and parallel syntheses of natural product-like morphan compounds in a one-pot reaction rather than through tedious multi-step reactions.展开更多
Electrocatalytic 5-hydroxymethylfurfural oxidation reaction(HMFOR)provides a promising strategy to convert biomass derivative to highvalue-added chemicals.Herein,a cascade strategy is proposed to construct Pd-NiCo_(2)...Electrocatalytic 5-hydroxymethylfurfural oxidation reaction(HMFOR)provides a promising strategy to convert biomass derivative to highvalue-added chemicals.Herein,a cascade strategy is proposed to construct Pd-NiCo_(2)O_(4)electrocatalyst by Pd loading on Ni-doped Co3O4 and for highly active and stable synergistic HMF oxidation.An elevated current density of 800 mA cm^(-2)can be achieved at 1.5 V,and both Faradaic efficiency and yield of 2,5-furandicarboxylic acid remained close to 100%over 10 consecutive electrolysis.Experimental and theoretical results unveil that the introduction of Pd atoms can modulate the local electronic structure of Ni/Co,which not only balances the competitive adsorption of HMF and OH-species,but also promote the active Ni^(3+)species formation,inducing high indirect oxidation activity.We have also discovered that Ni incorporation facilitates the Co2+pre-oxidation and electrophilic OH*generation to contribute direct oxidation process.This work provides a new approach to design advanced electrocatalyst for biomass upgrading.展开更多
An efficient Cu catalyzed selective arylation/annulation cascade reaction of 2-alkynylanilines with diaryliodonium salts was developed.This reaction was selective to N-arylation instead of C-arylation,which provides a...An efficient Cu catalyzed selective arylation/annulation cascade reaction of 2-alkynylanilines with diaryliodonium salts was developed.This reaction was selective to N-arylation instead of C-arylation,which provides a simple synthetic method for N-aryl indoles.展开更多
An efficient and novel procedure for the preparation of pyrazolo[3,4-b]pyridine derivatives through multi-component reaction of aldehyde, 5-amino-3-methyl-1-phenylpyrazole and malononitrile or cyanoacetate in [bmim][B...An efficient and novel procedure for the preparation of pyrazolo[3,4-b]pyridine derivatives through multi-component reaction of aldehyde, 5-amino-3-methyl-1-phenylpyrazole and malononitrile or cyanoacetate in [bmim][BF4] is described in this paper. Advantages of the method presented here include mild conditions, high yields together with a green nature and ease of recovery and reuse of the reaction medium.展开更多
Oxonium ylide intermediates generated from α-diazocarbonyl compounds and water were trapped by Zn(Ⅱ)-activated α- dicarbonyl compounds. The reaction gave α,β-dihydroxyl acid derivatives in moderate yield.
A novel type of palladium-catalyzed cascade cyclization-coupling reaction has been found. Reaction of N, N-diallylbenzoylamide 1 with benzyl halides 2 afforded the corresponding dihydropyrroles 3 in moderate to excel...A novel type of palladium-catalyzed cascade cyclization-coupling reaction has been found. Reaction of N, N-diallylbenzoylamide 1 with benzyl halides 2 afforded the corresponding dihydropyrroles 3 in moderate to excellent yields.展开更多
The access to high-density hydrocarbon fuels from biomass for the reduction of dependence on fossil resources has been a research highlight in recent years. It is well known that cycloalkanes are the components of fue...The access to high-density hydrocarbon fuels from biomass for the reduction of dependence on fossil resources has been a research highlight in recent years. It is well known that cycloalkanes are the components of fuels with higher energy density than straight or branched alkanes. Herein, we developed a new catalytic pattern to synthesize dimethyltetradecahydroanthracenes(DMTHA), a kind of tricyclic alkane, from biomass-derived isoprene and p-benzoquinone via a cascade Diels-Alder reaction followed by a hydrodeoxygenation reaction. Vanadium supported on titanium dioxide(V-TiO_(2)) was applied to catalyze the cascade Diels-Alder reaction and it was disclosed that V with appropriate V^(4+)/V^(5+) ratio on the surface of TiO_(2) could activate quinones. Experimental tests showed that the heating value of final products was up to 45.7 MJ/kg. The development of new high-density fuel molecules is a long-term trend for the future renewable and sustainable fuel energy application.展开更多
An asymmetric total synthesis of(+)-21-epi-eburnamonine has been achieved.Key features of the synthesis include a visible-light photocatalytic intra-/intramolecular radical cascade reaction to assemble the tetracyclic...An asymmetric total synthesis of(+)-21-epi-eburnamonine has been achieved.Key features of the synthesis include a visible-light photocatalytic intra-/intramolecular radical cascade reaction to assemble the tetracyclic ABCD ring system,and a highly diastereoselective Johnson-Claisen rearrangement to establish the C20 all-carbon quaternary stereocenter.展开更多
The thermal neutron capture gamma radiations for 51V(n, g)52V reaction have been studied at Dalat Nuclear Research Reactor (DNRR). The gamma two-step cascade transition was measured by event-event coincidence spectrom...The thermal neutron capture gamma radiations for 51V(n, g)52V reaction have been studied at Dalat Nuclear Research Reactor (DNRR). The gamma two-step cascade transition was measured by event-event coincidence spectrometer. The added-neutron binding energy in 52V was measured as 7.31 MeV. Energy and the intensity transition of cascades were consistent with prediction of single particle model. Furthermore, the spin and the parity of levels were confined.展开更多
Organocatalytic cascade reactions represent a powerful strategy for the rapid construction of complex chiral molecules with multiple stereocenters from simple substrates under mild conditions. The intriguing structura...Organocatalytic cascade reactions represent a powerful strategy for the rapid construction of complex chiral molecules with multiple stereocenters from simple substrates under mild conditions. The intriguing structural feature and diverse reactivity of catalytically generated dienolate species render them competent and versatile intermediates for the development of practical and valuable cascade reactions. Over the past years, a plethora of innovative and pioneering noncovalent ammonium dienolatemediated cascade reactions have been designed and implemented under the catalysis of chiral organocatalysts, making dienolate activation a general, robust, and complementary method for the functionalization of unsaturated carbonyl compounds and related substances. This review illustrates the recent advances in organocatalytic noncovalent ammonium dienolate-mediated cascade reactions(mainly from 2010 to 2023), including the cascade transformations of ammonium dienolates directly generated from unsaturated ketone/aldehyde, ester/lactone/azlactone, amide/lactam/pyrazolone/oxindole, and alkylidene nitrile compounds. The contents are arranged based on the reaction types of the ammonium dienolates, with an emphasis on cascade 2,5-, 3,5-, and 4,5-difunctionalizations of these intermediates. Furthermore, other cascade reactions involving the 1,3-, 2,3-, and even more complex 3,4,5-reactivities of ammonium dienolates were also discussed. The reaction pathway, reaction stereoinduction, and synthetic applications of the ammonium dienolate-mediated cascade reactions were highlighted throughout the article. As a stimulating and ever-growing research area, the organocatalytic noncovalent ammonium dienolate-mediated cascade reactions are expected to continue demonstrating their magic power for constructing chiral targets in the future and further expanding the boundaries of asymmetric catalysis.展开更多
Bridged polycyclic lactams are important structural units in organic functional materials,natural products,and pharmaceuticals.A flexible and efficient anion cascade reaction was developed for the preparation of bridg...Bridged polycyclic lactams are important structural units in organic functional materials,natural products,and pharmaceuticals.A flexible and efficient anion cascade reaction was developed for the preparation of bridged polycyclic lactams from readily available malonamides and 1,4‑dien-3-ones.Various highly substituted bridged polycyclic lactams were synthesized in good to excellent yields by tandem nucleophilic sequences in the presence of t BuOK in commercially available EtOH solvent at 60℃.Notably,the simple reactions can be run on a gram scale.Mechanistically,bis-Michael addition reaction and hemiaminalization reactions are involved in the tandem transformation.展开更多
Reconstructing enzymatic active sites presents a significant challenge due to the intricacies involved in achieving enzyme-like scaffold folding and spatial arrangement of essential functional groups.There is also a g...Reconstructing enzymatic active sites presents a significant challenge due to the intricacies involved in achieving enzyme-like scaffold folding and spatial arrangement of essential functional groups.There is also a growing interest in building biocatalytic networks,wherein multiple enzymatic active sites are localized within a single artificial system,allowing for cascaded transformations.In this work,we report the self-assembly of imidazole or its derivatives with fluorenylmethyloxycarbonyl-modified histidine and Cu2+to fabricate a supramolecular catalyst,which possesses catechol oxidase-like dicopper center with multiple imidazole as the coordination sphere.Transmission electron microscopy,low-temperature X-band continuous-wave electron paramagnetic resonance,K-edge X-ray absorption spectra/the extended X-ray absorption fine structure analysis,and density functional theory modeling were used for the structural characterization of the catalyst.The phenol derivatives and the dissolved oxygen were used as the substrates,with the addition of 4-aminoantipyrine to generate a red adduct with a maximum absorbance at 510 nm,for obtaining time-dependent absorbance change curves and estimating the activities.The results reveal that the addition of imidazole synergistically accelerates the oxidative activity about 10-fold and the hydrolysis activity about 14-fold than fluorenylmethyloxycarbonyl modified-histidine/Cu2+.The supramolecular nanoassembly also exhibits the ability to catalyze oxidation/hydrolysis cascade reactions,converting 2′,7′-dichlorofluorescin diacetate into 2′,7′-dichlorofluorescein.This process can be regulated through the methylation of the imidazole component at various positions.This work may contribute to the design of advanced biomimetic catalysts,and shed light on early structural models of the active sites of the primitive copper-dependent enzymes.展开更多
A novel method for the preparation of highly functionalized 4-oxo-3-(1H-pyrrol-3-yl)-4H-chromenes(OPCMs)from 3-formylchromones andα-isocyanoacetates via an unprecedented three-component[1+1+3]cycloaddition reaction i...A novel method for the preparation of highly functionalized 4-oxo-3-(1H-pyrrol-3-yl)-4H-chromenes(OPCMs)from 3-formylchromones andα-isocyanoacetates via an unprecedented three-component[1+1+3]cycloaddition reaction in one pot was developed.The three-component cascade reaction was enabled by refluxing a mixture of the substrates in 1,4-dioxane in the presence of Ag_(2)CO_(3) as a Lewis acid promoter.As a result,a series of functionalized pyrroles(OPCMs,3),was prepared regioselectively and in high yields(80%-88%)through the formation of three bonds.This protocol can be used in the synthesis of OPCMs rather than through conventional,multi-step reactions and is suitable for both combinatorial and parallel syntheses of pyrroles.展开更多
Multi-enzyme complexes are the results of natural evolution to facilitate cascade biocatalysis.Through enzyme colocalization within a complex,the transfer efficiency of reaction intermediates between adjacent cascade ...Multi-enzyme complexes are the results of natural evolution to facilitate cascade biocatalysis.Through enzyme colocalization within a complex,the transfer efficiency of reaction intermediates between adjacent cascade enzymes can be promoted,resulting in enhanced overall reaction efficiency.Inspired by nature,a variety of approaches have been developed for the assembly of artificial multi-enzyme complexes with different spatial organizations,aiming at improving the catalytic efficiency of enzyme cascade.A recent trend of this research area is the creation of enzyme complexes with a controllable spatial organization which helps with the mechanistic studies and bears the potential to further increase metabolic productivity.In this review,we summarize versatile strategies for the assembly of artificial multi-enzyme complexes,followed by an inspection of the mechanistic studies of artificial multi-enzyme complexes for their enhancement of catalytic efficiency.Furthermore,we provide some highlighted in vivo,ex vivo,and in vitro examples that demonstrate the ability of artificial multi-enzyme complexes for enhancing the overall production efficiency of value-added compounds.Recent research progress has revealed the great biotechnological potential of artificial multi-enzyme complexes as a powerful tool for biomanufacturing.展开更多
A mild, cascade type methodology was developed for the synthesis of polyphenolic ethers by the palladium-catalyzed cross coupling of phenols and halo compounds under microwave heating. In most cases, reactions run in ...A mild, cascade type methodology was developed for the synthesis of polyphenolic ethers by the palladium-catalyzed cross coupling of phenols and halo compounds under microwave heating. In most cases, reactions run in neat conditions and in some cases, IPA/water mixture, and 1,4-dioxane were employed as solvents to furnish the products. By applying this new method, we were able to synthesize and purify a good number of polyether compounds with complete spectral data.展开更多
An electrocatalytic multicomponent cascade cross-coupling for the synthesis of chalcogenosulfonates has been established.This approach does not require the use of transition metals,acids,and external oxidants.The gent...An electrocatalytic multicomponent cascade cross-coupling for the synthesis of chalcogenosulfonates has been established.This approach does not require the use of transition metals,acids,and external oxidants.The gentle conditions and tolerance to a wide variety of functional groups permit the derivatization of complex indoles.展开更多
基金We are grateful for financial support from the Natural Science Foundation of Yunnan Province,China(No.2019FY003003)the Scientific and Technological Innovation Team of Green Synthesis and Activity Research of Natural-like Heterocyclic Compound Libraries in Universities of Yunnan Province(No.C17624011121).The authors thank the Advanced Analysis and Measurement Center of Yunnan University for the sample testing service.
文摘A novel protocol for the preparation of highly functionalized 2-azabicyclo[3.3.1]nonane(morphan)derivatives via a multicomponent cascade reaction,involving 3-formylchromones,2-naphthols,and enaminones in the ionic liquid[BMIM]PF6 as the solvent and promoted by 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU),was developed,which involved the cleavage of one C–O bond and formation of four bonds(1 C–O,1 C–N,and 2 C–C bonds).As a result,a series of morphan derivatives were produced through a cascade reaction,including a sequence of 1,2-addition,enol-keto tautomerization,Michael addition,dehydration,another Michael addition,imine-enamine tautomerization,and N-alkylation reactions,which were accompanied by a ring-opening reaction.This protocol was suitable for combinatorial and parallel syntheses of natural product-like morphan compounds in a one-pot reaction rather than through tedious multi-step reactions.
基金financially supported by Key Research and Development Projects of Sichuan Province (2023YFG0222)“Tianfu Emei” Science and Technology Innovation Leader Program in Sichuan Province (2021)+3 种基金University of Electronic Science and Technology of China Talent Start-up Funds (A1098 5310 2360 1208)the Youth Innovation Promotion Association of CAS (2020458)National Natural Science Foundation of China (21464015, 21472235, 52122212, 12274391, 223210001)Beijing Natural Science Foundation (IS23045)
文摘Electrocatalytic 5-hydroxymethylfurfural oxidation reaction(HMFOR)provides a promising strategy to convert biomass derivative to highvalue-added chemicals.Herein,a cascade strategy is proposed to construct Pd-NiCo_(2)O_(4)electrocatalyst by Pd loading on Ni-doped Co3O4 and for highly active and stable synergistic HMF oxidation.An elevated current density of 800 mA cm^(-2)can be achieved at 1.5 V,and both Faradaic efficiency and yield of 2,5-furandicarboxylic acid remained close to 100%over 10 consecutive electrolysis.Experimental and theoretical results unveil that the introduction of Pd atoms can modulate the local electronic structure of Ni/Co,which not only balances the competitive adsorption of HMF and OH-species,but also promote the active Ni^(3+)species formation,inducing high indirect oxidation activity.We have also discovered that Ni incorporation facilitates the Co2+pre-oxidation and electrophilic OH*generation to contribute direct oxidation process.This work provides a new approach to design advanced electrocatalyst for biomass upgrading.
基金supported by the Intercollegiate Key Scientific Research Projects of Henan Province(15A150018)~~
文摘An efficient Cu catalyzed selective arylation/annulation cascade reaction of 2-alkynylanilines with diaryliodonium salts was developed.This reaction was selective to N-arylation instead of C-arylation,which provides a simple synthetic method for N-aryl indoles.
基金the National Natural Science Foundation of China(No.20573034).
文摘An efficient and novel procedure for the preparation of pyrazolo[3,4-b]pyridine derivatives through multi-component reaction of aldehyde, 5-amino-3-methyl-1-phenylpyrazole and malononitrile or cyanoacetate in [bmim][BF4] is described in this paper. Advantages of the method presented here include mild conditions, high yields together with a green nature and ease of recovery and reuse of the reaction medium.
基金supported by National Science Foundation of China(No.20772033)China postdoctoral Science Foundation(No.20080440607)
文摘Oxonium ylide intermediates generated from α-diazocarbonyl compounds and water were trapped by Zn(Ⅱ)-activated α- dicarbonyl compounds. The reaction gave α,β-dihydroxyl acid derivatives in moderate yield.
文摘A novel type of palladium-catalyzed cascade cyclization-coupling reaction has been found. Reaction of N, N-diallylbenzoylamide 1 with benzyl halides 2 afforded the corresponding dihydropyrroles 3 in moderate to excellent yields.
基金the National Key R&D Program of China (2019YFC1905303, 2018YFB1501600)the National Natural Science Foundation of China (21908218, 21872139)DICP Grant (I201944) for providing financial support to do this scientific research。
文摘The access to high-density hydrocarbon fuels from biomass for the reduction of dependence on fossil resources has been a research highlight in recent years. It is well known that cycloalkanes are the components of fuels with higher energy density than straight or branched alkanes. Herein, we developed a new catalytic pattern to synthesize dimethyltetradecahydroanthracenes(DMTHA), a kind of tricyclic alkane, from biomass-derived isoprene and p-benzoquinone via a cascade Diels-Alder reaction followed by a hydrodeoxygenation reaction. Vanadium supported on titanium dioxide(V-TiO_(2)) was applied to catalyze the cascade Diels-Alder reaction and it was disclosed that V with appropriate V^(4+)/V^(5+) ratio on the surface of TiO_(2) could activate quinones. Experimental tests showed that the heating value of final products was up to 45.7 MJ/kg. The development of new high-density fuel molecules is a long-term trend for the future renewable and sustainable fuel energy application.
基金surpport from National Natural Science Foundation of China(21921002 and 21991114)National Science and Technology Major Projects for“Major New Drugs Innovation and Development”(2018ZX09711003-015 and 2018ZX09711001-005-004).
文摘An asymmetric total synthesis of(+)-21-epi-eburnamonine has been achieved.Key features of the synthesis include a visible-light photocatalytic intra-/intramolecular radical cascade reaction to assemble the tetracyclic ABCD ring system,and a highly diastereoselective Johnson-Claisen rearrangement to establish the C20 all-carbon quaternary stereocenter.
文摘The thermal neutron capture gamma radiations for 51V(n, g)52V reaction have been studied at Dalat Nuclear Research Reactor (DNRR). The gamma two-step cascade transition was measured by event-event coincidence spectrometer. The added-neutron binding energy in 52V was measured as 7.31 MeV. Energy and the intensity transition of cascades were consistent with prediction of single particle model. Furthermore, the spin and the parity of levels were confined.
基金supported by the National Natural Science Foundation of China (21871116, U22A20390)the Fundamental Research Funds for the Central Universities (lzujbky-2023-stlt01)the“111” program from the MOE of China。
文摘Organocatalytic cascade reactions represent a powerful strategy for the rapid construction of complex chiral molecules with multiple stereocenters from simple substrates under mild conditions. The intriguing structural feature and diverse reactivity of catalytically generated dienolate species render them competent and versatile intermediates for the development of practical and valuable cascade reactions. Over the past years, a plethora of innovative and pioneering noncovalent ammonium dienolatemediated cascade reactions have been designed and implemented under the catalysis of chiral organocatalysts, making dienolate activation a general, robust, and complementary method for the functionalization of unsaturated carbonyl compounds and related substances. This review illustrates the recent advances in organocatalytic noncovalent ammonium dienolate-mediated cascade reactions(mainly from 2010 to 2023), including the cascade transformations of ammonium dienolates directly generated from unsaturated ketone/aldehyde, ester/lactone/azlactone, amide/lactam/pyrazolone/oxindole, and alkylidene nitrile compounds. The contents are arranged based on the reaction types of the ammonium dienolates, with an emphasis on cascade 2,5-, 3,5-, and 4,5-difunctionalizations of these intermediates. Furthermore, other cascade reactions involving the 1,3-, 2,3-, and even more complex 3,4,5-reactivities of ammonium dienolates were also discussed. The reaction pathway, reaction stereoinduction, and synthetic applications of the ammonium dienolate-mediated cascade reactions were highlighted throughout the article. As a stimulating and ever-growing research area, the organocatalytic noncovalent ammonium dienolate-mediated cascade reactions are expected to continue demonstrating their magic power for constructing chiral targets in the future and further expanding the boundaries of asymmetric catalysis.
基金National Natural Science Foundation of China(NSFC,Nos.21772032,21877206,and 22101074)the 111 Project(No.D17007)+3 种基金Excellent Youth Foundation of Henan Scientific Committee(No.222300420012)China Postdoctoral Science Foundation(No.2019M660173)the Natural Science Foundation of Henan Province(No.202300410233)Henan Key Laboratory of Organic Functional Molecules and Drug Innovation for financial support。
文摘Bridged polycyclic lactams are important structural units in organic functional materials,natural products,and pharmaceuticals.A flexible and efficient anion cascade reaction was developed for the preparation of bridged polycyclic lactams from readily available malonamides and 1,4‑dien-3-ones.Various highly substituted bridged polycyclic lactams were synthesized in good to excellent yields by tandem nucleophilic sequences in the presence of t BuOK in commercially available EtOH solvent at 60℃.Notably,the simple reactions can be run on a gram scale.Mechanistically,bis-Michael addition reaction and hemiaminalization reactions are involved in the tandem transformation.
基金the National Natural Science Foundation of China(No.52173194)Beijing Natural Science Foundation(No.2232017)Fundamental Research Funds for the Central Universities(No.buctrc201902).
文摘Reconstructing enzymatic active sites presents a significant challenge due to the intricacies involved in achieving enzyme-like scaffold folding and spatial arrangement of essential functional groups.There is also a growing interest in building biocatalytic networks,wherein multiple enzymatic active sites are localized within a single artificial system,allowing for cascaded transformations.In this work,we report the self-assembly of imidazole or its derivatives with fluorenylmethyloxycarbonyl-modified histidine and Cu2+to fabricate a supramolecular catalyst,which possesses catechol oxidase-like dicopper center with multiple imidazole as the coordination sphere.Transmission electron microscopy,low-temperature X-band continuous-wave electron paramagnetic resonance,K-edge X-ray absorption spectra/the extended X-ray absorption fine structure analysis,and density functional theory modeling were used for the structural characterization of the catalyst.The phenol derivatives and the dissolved oxygen were used as the substrates,with the addition of 4-aminoantipyrine to generate a red adduct with a maximum absorbance at 510 nm,for obtaining time-dependent absorbance change curves and estimating the activities.The results reveal that the addition of imidazole synergistically accelerates the oxidative activity about 10-fold and the hydrolysis activity about 14-fold than fluorenylmethyloxycarbonyl modified-histidine/Cu2+.The supramolecular nanoassembly also exhibits the ability to catalyze oxidation/hydrolysis cascade reactions,converting 2′,7′-dichlorofluorescin diacetate into 2′,7′-dichlorofluorescein.This process can be regulated through the methylation of the imidazole component at various positions.This work may contribute to the design of advanced biomimetic catalysts,and shed light on early structural models of the active sites of the primitive copper-dependent enzymes.
基金the Natural Science Foundation of Yunnan Province(No.2019FY003003)the National Natural Science Foundation of China(No.21662042)the Scientific and Technological Innovation Team of Green Synthesis and Activity Research of Natural-like Heterocyclic Compound Libraries in Universities of Yunnan Province(No.C17624011121).
文摘A novel method for the preparation of highly functionalized 4-oxo-3-(1H-pyrrol-3-yl)-4H-chromenes(OPCMs)from 3-formylchromones andα-isocyanoacetates via an unprecedented three-component[1+1+3]cycloaddition reaction in one pot was developed.The three-component cascade reaction was enabled by refluxing a mixture of the substrates in 1,4-dioxane in the presence of Ag_(2)CO_(3) as a Lewis acid promoter.As a result,a series of functionalized pyrroles(OPCMs,3),was prepared regioselectively and in high yields(80%-88%)through the formation of three bonds.This protocol can be used in the synthesis of OPCMs rather than through conventional,multi-step reactions and is suitable for both combinatorial and parallel syntheses of pyrroles.
基金supported by the National Natural Science Foundation of China(21778073)。
文摘Multi-enzyme complexes are the results of natural evolution to facilitate cascade biocatalysis.Through enzyme colocalization within a complex,the transfer efficiency of reaction intermediates between adjacent cascade enzymes can be promoted,resulting in enhanced overall reaction efficiency.Inspired by nature,a variety of approaches have been developed for the assembly of artificial multi-enzyme complexes with different spatial organizations,aiming at improving the catalytic efficiency of enzyme cascade.A recent trend of this research area is the creation of enzyme complexes with a controllable spatial organization which helps with the mechanistic studies and bears the potential to further increase metabolic productivity.In this review,we summarize versatile strategies for the assembly of artificial multi-enzyme complexes,followed by an inspection of the mechanistic studies of artificial multi-enzyme complexes for their enhancement of catalytic efficiency.Furthermore,we provide some highlighted in vivo,ex vivo,and in vitro examples that demonstrate the ability of artificial multi-enzyme complexes for enhancing the overall production efficiency of value-added compounds.Recent research progress has revealed the great biotechnological potential of artificial multi-enzyme complexes as a powerful tool for biomanufacturing.
文摘A mild, cascade type methodology was developed for the synthesis of polyphenolic ethers by the palladium-catalyzed cross coupling of phenols and halo compounds under microwave heating. In most cases, reactions run in neat conditions and in some cases, IPA/water mixture, and 1,4-dioxane were employed as solvents to furnish the products. By applying this new method, we were able to synthesize and purify a good number of polyether compounds with complete spectral data.
基金funding supports from Guizhou Provincial Basic Research Program(Natural Science)(No.QianKeHeJiChu-ZK[2024]YiBan086)the starting grant of Guizhou University[(2023)5].
文摘An electrocatalytic multicomponent cascade cross-coupling for the synthesis of chalcogenosulfonates has been established.This approach does not require the use of transition metals,acids,and external oxidants.The gentle conditions and tolerance to a wide variety of functional groups permit the derivatization of complex indoles.