Selective reductive amination of carbonyl compounds with high activity is very essential for the chemical and pharmaceutical industry,but scarcely successful paradigm was reported via efficient photocatalytic reaction...Selective reductive amination of carbonyl compounds with high activity is very essential for the chemical and pharmaceutical industry,but scarcely successful paradigm was reported via efficient photocatalytic reactions.Herein,the ultrasmall Ru nanoclusters(~0.9 nm)were successfully fabricated over P25 support with positive charged Ru^(δ+)species at the interface.A new route was developed to achieve the furfural(FAL)to furfurylamine(FAM)by coupling the light-driven reductive amination and hydrogen transfer of ethanol over this type catalyst.Strikingly,the photocatalytic activity and selectivity are strongly dependent on the particle size and electronic structure of Ruthenium.The Ru^(δ+)species at the interface promote the formation of active imine intermediates;moreover,the Ru nanoclusters facilitate the separation efficiency of electrons and holes as well as accelerate the further hydrogenation of imine intermediates to product primary amines.In contrast Ru particles in larger nanometer size facilitate the formation of the furfuryl alcohol and excessive hydrogenation products.In addition,the coupling byproducts can be effectively inhibited via the construction of sub-nanocluster.This study offers a new path to produce the primary amines from biomass-derived carbonyl compounds over hybrid semiconductor/metal-clusters photocatalyst via light-driven tandem catalytic process.展开更多
Synthesizing nitrogen(N)-containing molecules from biomass derivatives is a new strategy for production of this kind of chemicals.Herein,for the first time we present the synthesis of N-substituted aryl pyrroles via r...Synthesizing nitrogen(N)-containing molecules from biomass derivatives is a new strategy for production of this kind of chemicals.Herein,for the first time we present the synthesis of N-substituted aryl pyrroles via reductive amination/cyclization of levulinic acid(LA)with primary aromatic amines and hydrosilanes(e.g.,PMHS)over Cs F,and a series of N-substituted aryl pyrroles could be obtained in good to excellent yields at 120○C.The mechanism investigation indicates that the reaction proceeds in two steps:the cyclization between amine and LA occurs first to form intermediate 5-methyl-N-alkyl-1,3-dihydro-2H-pyrrolones and their isomeride(B),and then the chemo-and region-selective reduction of intermediates take place to produce the final products.This approach for synthesis of N-substituted aryl pyrroles can be performed under mild and green conditions,which may have promising applications.展开更多
A highly efficient and green process was developed for the synthesis of useful 5-amino-1-pentanol(5-AP)from biomass-derived dihydropyran by coupling the in situ generation of 5-hydroxypentanal(5-HP,via the ring-openin...A highly efficient and green process was developed for the synthesis of useful 5-amino-1-pentanol(5-AP)from biomass-derived dihydropyran by coupling the in situ generation of 5-hydroxypentanal(5-HP,via the ring-opening tautomerization of 2-hydroxytetrahydropyran(2-HTHP))and its reductive amination over supported Ni catalysts.The catalytic performances of the supported Ni catalysts on different oxides including SiO2,TiO2,ZrO2,γ-Al2 O3,and MgO as well as several commercial hydrogenation catalysts were investigated.The Ni/ZrO2 catalyst presented the highest 5-AP yield.The characterization results of the oxide-supported Ni catalysts showed that the Ni/ZrO2 catalyst possessed high reducibility and a high surface acid density,which lead to the enhanced activity and selectivity of the catalyst.The effect of reaction parameters on the catalytic performance of the Ni/ZrO2 catalyst was studied,and a high 5-AP yield of 90.8%was achieved in the reductive amination of 2-HTHP aqueous solution under mild conditions of 80℃and 2 MPa H2.The stability of the Ni/ZrO2 catalyst was studied using a continuous flow reactor,and only a slight decrease in the 5-AP yield was observed after a 90-h time-on-stream.Additionally,the reaction pathways for the reductive amination of 2-HTHP to synthesize 5-AP were proposed.展开更多
ZrCl4/Hantzsch 1,4-dihydropyridine is a mild and highly efficient reagent combination for the direct reductive amination. Weakly basic amines such as anilines substituted by electron-withdrawing group and heteroaromat...ZrCl4/Hantzsch 1,4-dihydropyridine is a mild and highly efficient reagent combination for the direct reductive amination. Weakly basic amines such as anilines substituted by electron-withdrawing group and heteroaromatic amines can be reductively alkylated with electron rich aldehydes and ketones under mild conditions to form the secondary amines in excellent yields.展开更多
A simple and convenient procedure for the preparation of amines from aldehydes and ketones with sodium borohydride activated by silica chloride as a catalyst under solvent-free conditions is described.A variety of ali...A simple and convenient procedure for the preparation of amines from aldehydes and ketones with sodium borohydride activated by silica chloride as a catalyst under solvent-free conditions is described.A variety of aliphatic and aromatic aldehydes,ketones and amines when mixed with NaBH;/silica chloride at room temperature,afforded excellent yield of the corresponding amines.展开更多
The asymmetric reductive amination of achiral ketones with ammonia is a particularly attractive reaction for the synthesis of chiral amines.Although several engineered amine dehydrogenases have been developed by prote...The asymmetric reductive amination of achiral ketones with ammonia is a particularly attractive reaction for the synthesis of chiral amines.Although several engineered amine dehydrogenases have been developed by protein engineering for the asymmetric reductive amination of ketones,they all display(R)‐stereoselectivity.To date,there is no report of an(S)‐stereoselective biocatalyst for this reaction.Herein,a microorganism named Brevibacterium epidermidis ECU1015 that catalyzes the(S)‐selective reductive amination of ketones with ammonium has been successfully isolated from soil.Using B.epidermidis ECU1015 as the catalyst,the asymmetric reductive amination of a set of phenylacetone derivatives was successfully carried out,yielding the corresponding(S)‐chiral amines with moderate conversion and>99%enantiomeric excess.展开更多
The reductive amination of furfural to furfurylamine is an important and still challenging topic in the field of biomass conversion. In this work, we prepared a series of Ni/Al_(2)O_(3)-LaO_(x) catalysts by co-precipi...The reductive amination of furfural to furfurylamine is an important and still challenging topic in the field of biomass conversion. In this work, we prepared a series of Ni/Al_(2)O_(3)-LaO_(x) catalysts by co-precipitation method, the role of La played in promoting the catalytic performances of reductive amination furfural was discussed based on the changes in the electronic state of Ni species, acidity, and Ni particle size. The catalytic activity and the selectivity of furfurylamine are highly dependent on the surface properties and the structure of the catalyst. The addition of La promoted the amount of strong acidic sites and the H2dissociation and spillover on the surface, thus inducing the improvement of the catalytic activity and furfurylamine selectivity. The Ni/Al_(2)O_(3)-0.5LaO_(x)catalyst with suitable acid sites gave a high yield of furfurylamine (94.9%) under mild reaction conditions. Moreover, the catalyst could be recycled five times without significant loss in activity. The Ni/Al_(2)O_(3)-LaO_(x) catalyst is of great promise in the production of amines via reductive amination reaction.展开更多
Asymmetric reductive amination directly converts ketones and amines to alkylamines, which are important motifs in medicines.We report that cationic nickel complexes of chiral diphosphines promote enantioselective redu...Asymmetric reductive amination directly converts ketones and amines to alkylamines, which are important motifs in medicines.We report that cationic nickel complexes of chiral diphosphines promote enantioselective reductive amination of benzylic ketones with both arylamines and benzhydrazide. Isopropanol was used as a safe and cheap source of hydrogen instead of formic acid. The reaction can be readily applied to a concise synthesis of diarylethylamines, a class of neuroactive substances.展开更多
The efficient synthesis of useful primary amines via reductive amination of biomass-based aldehydes and ketones over earth-abundant base metal catalysts is an attractive biomass value-adding technology yet facing lots...The efficient synthesis of useful primary amines via reductive amination of biomass-based aldehydes and ketones over earth-abundant base metal catalysts is an attractive biomass value-adding technology yet facing lots of challenges.Herein,natural attapulgite(ATP)was applied as support for the fabrication of active Ni catalysts with different Ni loadings(5–30 wt%)by the deposition-precipitation method.The Ni/ATP-550 catalyst with 10–15 wt%Ni loadings was found to present the highest catalytic performance for the synthesis of valuable 5-amino-1-pentanol(5-AP)via reductive amination of biofurfural-derived 2-hydroxytetrahydropyran among a variety of commonly used oxide supports loaded Ni catalysts,as well as ATP supported nickel catalysts with other loadings,achieving 5-AP yield up to 94%.The intrinsic activity of the Ni/ATP catalysts was found to depend strongly on the Ni^(0) crystallite size and Ni^(0) fraction of the catalysts,which generally increased with increasing Ni^(0) crystallite size and fraction,owing probably to the hydrogenation of imine intermediate is a structure-sensitive reaction.The efficient 10Ni/ATP-550 catalyst also exhibited good activity and stability in the reductive amination of several other biomass-derived aldehydes and ketones to their corresponding primary amines with good to excellent yields(81%–99%).This work provided a clean and efficient natural ATP-supported non-noble metal nickel-based catalytic system for the reductive amination of aldehydes and ketones to synthesize high-value-added primary amines,which could be a promising candidate for the industrial production of amines.展开更多
Direct reductive amination(DRA)is one of the most efficient methods for amine synthesis.Herein we report a practical homogeneous DRA procedure utilizing iridium catalysis.Applying simple,readily available and inexpens...Direct reductive amination(DRA)is one of the most efficient methods for amine synthesis.Herein we report a practical homogeneous DRA procedure utilizing iridium catalysis.Applying simple,readily available and inexpensive PPh_(3)and alike ligands along with iridium at a low loading,aldehydes and ketones reductively coupled with primary and secondary amines to efficiently form structurally and functionally diverse amine products,including a set of drugs and compounds from late-stage manipulation.The reaction conditions were exceptionally mild and additive-free,in which oxygen,moisture,polar protic groups and multiple other functional groups were tolerated.For targeted products,this methodology is especially versatile for offering multiple possible synthetic options.The 10 gram-scale synthesis further demonstrated the potential and promise of this procedure in practical amine synthesis.DFT studies reveal an“outer-sphere”H-addition pathway,in whichπ-πinteractions and H-bonding play important roles.展开更多
The synthesis of primary amines via reductive amination in the presence of NH_(3)and H_(2),as a green and sustainable process,has attracted much attention.In this paper,we prepared series of Ni/SiO_(2)catalysts with d...The synthesis of primary amines via reductive amination in the presence of NH_(3)and H_(2),as a green and sustainable process,has attracted much attention.In this paper,we prepared series of Ni/SiO_(2)catalysts with deposition-precipitation and impregnation methods,and their catalytic performances on the reductive amination of a biomass derived compound of furfural to produce furfurylamine were studied.The catalytic activity and the yield were correlated to the structure and the surface properties of catalysts largely.The Ni/SiO_(2)is of high Lewis acidity and small Ni particle with numerous large Ni flat step surface showed high activity and selectivity,it afforded a reaction rate of 12.8 h^(−1)and a high yield to furfurylamine around 98%.These results are superior to the most non-noble metal catalysts reported so far.Moreover,the reaction route was examined with the unit control reactions of the intermediate.To produce furfurylamine selectively,the most suitable catalyst should have the moderate but not the highest activity in activation of hydrogen and hydrogenation in the reductive amination of furfural.This work provides some useful information for the catalytic reductive amination of aldehydes both in the design of catalyst and the reaction route.展开更多
A novel tandem reductive amination/intermolecular nucleophilic aromatic substitution (SNAr) sequence has been established for the synthesis of amine containing pyrimidine in formation of one carbon-oxygen and one carb...A novel tandem reductive amination/intermolecular nucleophilic aromatic substitution (SNAr) sequence has been established for the synthesis of amine containing pyrimidine in formation of one carbon-oxygen and one carbon-nitrogen bonds in a one-pot fashion. Treatment of aldehyde with arylamine, 2-methanesulfonyl-4,6-dimeth-oxypyrimidine and sodium borohydride provides good overall yield. The p-toluenesulfonic acid (PTSA) can be used as activator and is generally needed in the reaction. Dioxane is the preferred reaction solvent, but reactions can also be carried out in tetrahydrofuran (THF), MeCN, toluene and dichloromethane. The procedure is carried out effectively in the presence of K2CO3. The reaction proceeds smoothly with aromatic aldehydes and arylamines possessing elec-tron-donating or-withdrawing groups. This method can be applied to the synthesis of the oilseed rape herbicide and is superior to the classical one in several aspects: cutting out several purification steps, minimizing solvent use and chemical waste, and saving time. Its advantages such as operational convenience, high-efficient synthesis, and starting material availability make it a desirable method for preparing amines with molecular diversity and biological activity.展开更多
Hexamethylenediamine(HMDA) is an important reagent for the synthesis of Nylon-6,6, and it is usually produced by the hydrogenation of adiponitrile using a toxic reagent of hydrocyanic acid. Herein, we developed an env...Hexamethylenediamine(HMDA) is an important reagent for the synthesis of Nylon-6,6, and it is usually produced by the hydrogenation of adiponitrile using a toxic reagent of hydrocyanic acid. Herein, we developed an environmental friendly route to produce HMDA via catalytic reductive amination of 1,6-hexanediol(HDO) in the presence of hydrogen. The activities of several heterogeneous metal catalysts such as supported Ni, Co, Ru, Pt, Pd catalysts were screened for the present reaction in supercritical ammonia without any additives. Among the catalysts examined, Ru/Al_2O_3 presented a high catalytic activity and highest selectivity for the desired product of HMDA. The high performance of Ru/Al_2O_3 was discussed based on the Ru dispersion and the surface properties like the acid-basicity. In addition, the reaction parameters such as reaction temperature,time, H_2 and NH_3 pressure were examined, and the reaction processes were discussed in detail.展开更多
Reductive amination of aromatic aldehydes using NaBH4 and isoxazole amines is carried out in a Bronsted acidic ionic liquid 1 -methylimidazolium tetrafluoroborate [（HMIm）BF4]. The ionic liquid plays dual roles of so...Reductive amination of aromatic aldehydes using NaBH4 and isoxazole amines is carried out in a Bronsted acidic ionic liquid 1 -methylimidazolium tetrafluoroborate [（HMIm）BF4]. The ionic liquid plays dual roles of solvent as well as catalyst for the efficixcellent yields without any undesired side product formation. The newly synthesized compoundsent transformation of aromatic aldehydes to heterocyclic substituted amines in e （3, 6 and 7） were characterized by IR, 1H NMR and mass spectral techniques.展开更多
Heterogeneous iridium catalysts were prepared and applied for the reductive amination of aldehydes and ketones with nitroaromatics and amines using H2. The iridium catalysts were prepared by pyrolysis of ionic liquid ...Heterogeneous iridium catalysts were prepared and applied for the reductive amination of aldehydes and ketones with nitroaromatics and amines using H2. The iridium catalysts were prepared by pyrolysis of ionic liquid 1-methyl-3-cyanomethylimidazoulium chloride （[MCNI]C1） with iridium chloride （IrC13） in activated carbons. Iridium particles were well dispersed and stable in the N-doped carbon materials from [MCNI]C1 with activated carbon. The Ir@NC（600-2h） catalyst was found to be highly active and selective for the reductive amination of aldehydes and ketones using H2 and a variety of nitrobenzenes and amines were selectively converted into the corresponding secondary and tertiary amines. The Ir@NC（600-2h） catalyst can be reusable several times without evident deactivation.展开更多
A variety of secondary amines were obtained in high isolated yields in the reductive amination of aldehydes and ketones by using lithium amidoborane as reducing agent. Compared to ammonia borane, lithium amidoborane h...A variety of secondary amines were obtained in high isolated yields in the reductive amination of aldehydes and ketones by using lithium amidoborane as reducing agent. Compared to ammonia borane, lithium amidoborane has higher reducibility, and thus, exhibits faster reaction rate.展开更多
The synthesis of pyrrolidinones from reductive amination of levulinic acid （LA） with primary amines is reported.Pyrrolidinones have various applications such as surfactants,pharmaceutical intermediates,dispersants,a...The synthesis of pyrrolidinones from reductive amination of levulinic acid （LA） with primary amines is reported.Pyrrolidinones have various applications such as surfactants,pharmaceutical intermediates,dispersants,and solvents.The half-sandwich Cp＊Ir complex （Cp＊ is 1,2,3,4,5-pentamethylcyclopenta-l,3-diene） coordinated by bipyridine ligand bearing both dimethylamino and ortho-hydroxyl groups showed high catalytic activity for the reductive amination of LA.A range of primary amines,such as aromatic and benzyl amines,were readily converted to corresponding pyrrolidinones in good yields.展开更多
An efficient phase-transfer-catalyzed directed reductive amination of α-keto esters was described using simple substituted benzyl amines as nitrogen source and K2CO3 as base at room temperature, giving a series of al...An efficient phase-transfer-catalyzed directed reductive amination of α-keto esters was described using simple substituted benzyl amines as nitrogen source and K2CO3 as base at room temperature, giving a series of aliphatic a-amino acid derivatives in moderate to high yields（up to 99%）. Preliminary study on this asymmetric process showed that cinchona-derived phase transfer catalyst was elTective, aflbrding the corresponding product in 13% e.e. and 40% yield.展开更多
A highly efficient and enantioselective method for the asymmetric reductive amination ofβ-keto phosphine de-rivatives was disclosed,and the correspondingβ-amino phosphine oxides could be obtained in high yields(up t...A highly efficient and enantioselective method for the asymmetric reductive amination ofβ-keto phosphine de-rivatives was disclosed,and the correspondingβ-amino phosphine oxides could be obtained in high yields(up to 97%yield)and excellent enantioselectivities(up to 97%ee).Moreover,the reaction worked well on a gram scale,indicating that our protocol has potential applications in the synthesis of chiral ligands and organocatalysts.展开更多
Since the utilization of abundant biomass to develop advanced materials has become an utmost priority in recent years,we developed two sustainable routes(i.e.,the impregnation method and the one-pot synthesis)to prepa...Since the utilization of abundant biomass to develop advanced materials has become an utmost priority in recent years,we developed two sustainable routes(i.e.,the impregnation method and the one-pot synthesis)to prepare the hydrochar-supported catalysts and tested its catalytic performance on the reductive amination.Several techniques,such as TEM,XRD and XPS,were adopted to characterize the structural and catalytic features of samples.Results indicated that the impregnation method favors the formation of outer-sphere surface complexes with porous structure as well as well-distributed metallic nanoparticles,while the one-pot synthesis tends to form the inner-sphere surface complexes with relatively smooth appearance and amorphous metals.This difference explains the better activity of catalysts prepared by the impregnation method which can selectively convert benzaldehyde to benzylamine with an excellent yield of 93.7%under the optimal reaction conditions;in contrast,the catalyst prepared by the one-pot synthesis only exhibits a low selectivity near to zero.Furthermore,the gram-scale test catalyzed by the same catalysts exhibits a similar yield of benzylamine in comparison to its smaller scale,which is comparable to the previously reported heterogeneous noble-based catalysts.More surprisingly,the prepared catalysts can be expediently recycled by a magnetic bar and remain the satisfying catalytic activity after reusing up to five times.In conclusion,these developed catalysts enable the synthesis of functional amines with excellent selectivity and carbon balance,proving cost-effective and sustainable access to the wide application of reductive amination.展开更多
基金financially supported by the National Natural Science Foundation of China(202102007,21978147 and 21935001)the Fundamental Research Funds for the Central Universities(buctrc202112)。
文摘Selective reductive amination of carbonyl compounds with high activity is very essential for the chemical and pharmaceutical industry,but scarcely successful paradigm was reported via efficient photocatalytic reactions.Herein,the ultrasmall Ru nanoclusters(~0.9 nm)were successfully fabricated over P25 support with positive charged Ru^(δ+)species at the interface.A new route was developed to achieve the furfural(FAL)to furfurylamine(FAM)by coupling the light-driven reductive amination and hydrogen transfer of ethanol over this type catalyst.Strikingly,the photocatalytic activity and selectivity are strongly dependent on the particle size and electronic structure of Ruthenium.The Ru^(δ+)species at the interface promote the formation of active imine intermediates;moreover,the Ru nanoclusters facilitate the separation efficiency of electrons and holes as well as accelerate the further hydrogenation of imine intermediates to product primary amines.In contrast Ru particles in larger nanometer size facilitate the formation of the furfuryl alcohol and excessive hydrogenation products.In addition,the coupling byproducts can be effectively inhibited via the construction of sub-nanocluster.This study offers a new path to produce the primary amines from biomass-derived carbonyl compounds over hybrid semiconductor/metal-clusters photocatalyst via light-driven tandem catalytic process.
基金supported by Chinese Academy of Sciences,China(Grant No.QYZDY-SSW-SLH013-2)Henan Normal University,China。
文摘Synthesizing nitrogen(N)-containing molecules from biomass derivatives is a new strategy for production of this kind of chemicals.Herein,for the first time we present the synthesis of N-substituted aryl pyrroles via reductive amination/cyclization of levulinic acid(LA)with primary aromatic amines and hydrosilanes(e.g.,PMHS)over Cs F,and a series of N-substituted aryl pyrroles could be obtained in good to excellent yields at 120○C.The mechanism investigation indicates that the reaction proceeds in two steps:the cyclization between amine and LA occurs first to form intermediate 5-methyl-N-alkyl-1,3-dihydro-2H-pyrrolones and their isomeride(B),and then the chemo-and region-selective reduction of intermediates take place to produce the final products.This approach for synthesis of N-substituted aryl pyrroles can be performed under mild and green conditions,which may have promising applications.
基金supported by the National Natural Science Foundation of China(21872155,21473224)Cooperation Foundation of Dalian National Laboratory for Clean Energy(DNL 180303)+2 种基金Key Research Project of Frontier Science of Chinese Academy of Sciences(QYZDJ-SSW-SLH051)the Youth Innovation Promotion Association,CAS(2016371)the Suzhou Science and Technology Development Plan(SYG201626)~~
文摘A highly efficient and green process was developed for the synthesis of useful 5-amino-1-pentanol(5-AP)from biomass-derived dihydropyran by coupling the in situ generation of 5-hydroxypentanal(5-HP,via the ring-opening tautomerization of 2-hydroxytetrahydropyran(2-HTHP))and its reductive amination over supported Ni catalysts.The catalytic performances of the supported Ni catalysts on different oxides including SiO2,TiO2,ZrO2,γ-Al2 O3,and MgO as well as several commercial hydrogenation catalysts were investigated.The Ni/ZrO2 catalyst presented the highest 5-AP yield.The characterization results of the oxide-supported Ni catalysts showed that the Ni/ZrO2 catalyst possessed high reducibility and a high surface acid density,which lead to the enhanced activity and selectivity of the catalyst.The effect of reaction parameters on the catalytic performance of the Ni/ZrO2 catalyst was studied,and a high 5-AP yield of 90.8%was achieved in the reductive amination of 2-HTHP aqueous solution under mild conditions of 80℃and 2 MPa H2.The stability of the Ni/ZrO2 catalyst was studied using a continuous flow reactor,and only a slight decrease in the 5-AP yield was observed after a 90-h time-on-stream.Additionally,the reaction pathways for the reductive amination of 2-HTHP to synthesize 5-AP were proposed.
基金the National Natural Science Foundation of China （No. 20372030） for financial support.
文摘ZrCl4/Hantzsch 1,4-dihydropyridine is a mild and highly efficient reagent combination for the direct reductive amination. Weakly basic amines such as anilines substituted by electron-withdrawing group and heteroaromatic amines can be reductively alkylated with electron rich aldehydes and ketones under mild conditions to form the secondary amines in excellent yields.
基金support of this work from the Research Council of Mazandaran University gratefully acknowledged.
文摘A simple and convenient procedure for the preparation of amines from aldehydes and ketones with sodium borohydride activated by silica chloride as a catalyst under solvent-free conditions is described.A variety of aliphatic and aromatic aldehydes,ketones and amines when mixed with NaBH;/silica chloride at room temperature,afforded excellent yield of the corresponding amines.
基金supported by the National Natural Science Foundation of China(21472045,21536004)the National Defense Scientific and Technological Innovation Special Zone(17-163-12-ZT-003-055-01)~~
文摘The asymmetric reductive amination of achiral ketones with ammonia is a particularly attractive reaction for the synthesis of chiral amines.Although several engineered amine dehydrogenases have been developed by protein engineering for the asymmetric reductive amination of ketones,they all display(R)‐stereoselectivity.To date,there is no report of an(S)‐stereoselective biocatalyst for this reaction.Herein,a microorganism named Brevibacterium epidermidis ECU1015 that catalyzes the(S)‐selective reductive amination of ketones with ammonium has been successfully isolated from soil.Using B.epidermidis ECU1015 as the catalyst,the asymmetric reductive amination of a set of phenylacetone derivatives was successfully carried out,yielding the corresponding(S)‐chiral amines with moderate conversion and>99%enantiomeric excess.
基金the National Key Research and Development Program of China(No.2022YFA1504901)the National Natural Science Foundation of China(No.NSFC 22072142)the Science and Technology Development Program of Jilin Province,China(No.YDZJ202301ZYTS539).
文摘The reductive amination of furfural to furfurylamine is an important and still challenging topic in the field of biomass conversion. In this work, we prepared a series of Ni/Al_(2)O_(3)-LaO_(x) catalysts by co-precipitation method, the role of La played in promoting the catalytic performances of reductive amination furfural was discussed based on the changes in the electronic state of Ni species, acidity, and Ni particle size. The catalytic activity and the selectivity of furfurylamine are highly dependent on the surface properties and the structure of the catalyst. The addition of La promoted the amount of strong acidic sites and the H2dissociation and spillover on the surface, thus inducing the improvement of the catalytic activity and furfurylamine selectivity. The Ni/Al_(2)O_(3)-0.5LaO_(x)catalyst with suitable acid sites gave a high yield of furfurylamine (94.9%) under mild reaction conditions. Moreover, the catalyst could be recycled five times without significant loss in activity. The Ni/Al_(2)O_(3)-LaO_(x) catalyst is of great promise in the production of amines via reductive amination reaction.
基金supported by the National Natural Science Foundation of China (22271007)the Peking University Shenzhen Graduate School,State Key Laboratory of Chemical Oncogenomics,Shenzhen Bay Laboratory,and Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs。
文摘Asymmetric reductive amination directly converts ketones and amines to alkylamines, which are important motifs in medicines.We report that cationic nickel complexes of chiral diphosphines promote enantioselective reductive amination of benzylic ketones with both arylamines and benzhydrazide. Isopropanol was used as a safe and cheap source of hydrogen instead of formic acid. The reaction can be readily applied to a concise synthesis of diarylethylamines, a class of neuroactive substances.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.21872155 and 22102198)the Strategic Pilot Science and Technology Project of the Chinese Academy of Sciences(No.XDA21010700)the Western Young Scholar Program of the Chinese Academy of Sciences and the Open Project of Key Laboratory of Clay Mineral Applied Research of Gansu Province.
文摘The efficient synthesis of useful primary amines via reductive amination of biomass-based aldehydes and ketones over earth-abundant base metal catalysts is an attractive biomass value-adding technology yet facing lots of challenges.Herein,natural attapulgite(ATP)was applied as support for the fabrication of active Ni catalysts with different Ni loadings(5–30 wt%)by the deposition-precipitation method.The Ni/ATP-550 catalyst with 10–15 wt%Ni loadings was found to present the highest catalytic performance for the synthesis of valuable 5-amino-1-pentanol(5-AP)via reductive amination of biofurfural-derived 2-hydroxytetrahydropyran among a variety of commonly used oxide supports loaded Ni catalysts,as well as ATP supported nickel catalysts with other loadings,achieving 5-AP yield up to 94%.The intrinsic activity of the Ni/ATP catalysts was found to depend strongly on the Ni^(0) crystallite size and Ni^(0) fraction of the catalysts,which generally increased with increasing Ni^(0) crystallite size and fraction,owing probably to the hydrogenation of imine intermediate is a structure-sensitive reaction.The efficient 10Ni/ATP-550 catalyst also exhibited good activity and stability in the reductive amination of several other biomass-derived aldehydes and ketones to their corresponding primary amines with good to excellent yields(81%–99%).This work provided a clean and efficient natural ATP-supported non-noble metal nickel-based catalytic system for the reductive amination of aldehydes and ketones to synthesize high-value-added primary amines,which could be a promising candidate for the industrial production of amines.
基金supported by the National Natural Science Foundation of China(21772155)the National Key R&D Program of China(2020YFA0907901)the Scientific Fund of Northwest A&F University and Postdoctoral Science Foundation of China(2019M663827)。
文摘Direct reductive amination(DRA)is one of the most efficient methods for amine synthesis.Herein we report a practical homogeneous DRA procedure utilizing iridium catalysis.Applying simple,readily available and inexpensive PPh_(3)and alike ligands along with iridium at a low loading,aldehydes and ketones reductively coupled with primary and secondary amines to efficiently form structurally and functionally diverse amine products,including a set of drugs and compounds from late-stage manipulation.The reaction conditions were exceptionally mild and additive-free,in which oxygen,moisture,polar protic groups and multiple other functional groups were tolerated.For targeted products,this methodology is especially versatile for offering multiple possible synthetic options.The 10 gram-scale synthesis further demonstrated the potential and promise of this procedure in practical amine synthesis.DFT studies reveal an“outer-sphere”H-addition pathway,in whichπ-πinteractions and H-bonding play important roles.
基金the financial support from the National Natural Science Foundation of China(Nos.22172155 and 22072142)the Youth Innovation Promotion Association CAS(No.2016206).
文摘The synthesis of primary amines via reductive amination in the presence of NH_(3)and H_(2),as a green and sustainable process,has attracted much attention.In this paper,we prepared series of Ni/SiO_(2)catalysts with deposition-precipitation and impregnation methods,and their catalytic performances on the reductive amination of a biomass derived compound of furfural to produce furfurylamine were studied.The catalytic activity and the yield were correlated to the structure and the surface properties of catalysts largely.The Ni/SiO_(2)is of high Lewis acidity and small Ni particle with numerous large Ni flat step surface showed high activity and selectivity,it afforded a reaction rate of 12.8 h^(−1)and a high yield to furfurylamine around 98%.These results are superior to the most non-noble metal catalysts reported so far.Moreover,the reaction route was examined with the unit control reactions of the intermediate.To produce furfurylamine selectively,the most suitable catalyst should have the moderate but not the highest activity in activation of hydrogen and hydrogenation in the reductive amination of furfural.This work provides some useful information for the catalytic reductive amination of aldehydes both in the design of catalyst and the reaction route.
基金Project (Nos. Y407118 and D3080282) supported by the Natural Science Foundation of Zhejiang Province, China
文摘A novel tandem reductive amination/intermolecular nucleophilic aromatic substitution (SNAr) sequence has been established for the synthesis of amine containing pyrimidine in formation of one carbon-oxygen and one carbon-nitrogen bonds in a one-pot fashion. Treatment of aldehyde with arylamine, 2-methanesulfonyl-4,6-dimeth-oxypyrimidine and sodium borohydride provides good overall yield. The p-toluenesulfonic acid (PTSA) can be used as activator and is generally needed in the reaction. Dioxane is the preferred reaction solvent, but reactions can also be carried out in tetrahydrofuran (THF), MeCN, toluene and dichloromethane. The procedure is carried out effectively in the presence of K2CO3. The reaction proceeds smoothly with aromatic aldehydes and arylamines possessing elec-tron-donating or-withdrawing groups. This method can be applied to the synthesis of the oilseed rape herbicide and is superior to the classical one in several aspects: cutting out several purification steps, minimizing solvent use and chemical waste, and saving time. Its advantages such as operational convenience, high-efficient synthesis, and starting material availability make it a desirable method for preparing amines with molecular diversity and biological activity.
基金supported by the National Basic Research Program of China(2016YFA0602900)Youth Innovation Promotion Association CAS(2016206)Jilin Provincial Science and Technology Program of China(20150301012GX)
文摘Hexamethylenediamine(HMDA) is an important reagent for the synthesis of Nylon-6,6, and it is usually produced by the hydrogenation of adiponitrile using a toxic reagent of hydrocyanic acid. Herein, we developed an environmental friendly route to produce HMDA via catalytic reductive amination of 1,6-hexanediol(HDO) in the presence of hydrogen. The activities of several heterogeneous metal catalysts such as supported Ni, Co, Ru, Pt, Pd catalysts were screened for the present reaction in supercritical ammonia without any additives. Among the catalysts examined, Ru/Al_2O_3 presented a high catalytic activity and highest selectivity for the desired product of HMDA. The high performance of Ru/Al_2O_3 was discussed based on the Ru dispersion and the surface properties like the acid-basicity. In addition, the reaction parameters such as reaction temperature,time, H_2 and NH_3 pressure were examined, and the reaction processes were discussed in detail.
文摘Reductive amination of aromatic aldehydes using NaBH4 and isoxazole amines is carried out in a Bronsted acidic ionic liquid 1 -methylimidazolium tetrafluoroborate [（HMIm）BF4]. The ionic liquid plays dual roles of solvent as well as catalyst for the efficixcellent yields without any undesired side product formation. The newly synthesized compoundsent transformation of aromatic aldehydes to heterocyclic substituted amines in e （3, 6 and 7） were characterized by IR, 1H NMR and mass spectral techniques.
文摘Heterogeneous iridium catalysts were prepared and applied for the reductive amination of aldehydes and ketones with nitroaromatics and amines using H2. The iridium catalysts were prepared by pyrolysis of ionic liquid 1-methyl-3-cyanomethylimidazoulium chloride （[MCNI]C1） with iridium chloride （IrC13） in activated carbons. Iridium particles were well dispersed and stable in the N-doped carbon materials from [MCNI]C1 with activated carbon. The Ir@NC（600-2h） catalyst was found to be highly active and selective for the reductive amination of aldehydes and ketones using H2 and a variety of nitrobenzenes and amines were selectively converted into the corresponding secondary and tertiary amines. The Ir@NC（600-2h） catalyst can be reusable several times without evident deactivation.
文摘A variety of secondary amines were obtained in high isolated yields in the reductive amination of aldehydes and ketones by using lithium amidoborane as reducing agent. Compared to ammonia borane, lithium amidoborane has higher reducibility, and thus, exhibits faster reaction rate.
文摘The synthesis of pyrrolidinones from reductive amination of levulinic acid （LA） with primary amines is reported.Pyrrolidinones have various applications such as surfactants,pharmaceutical intermediates,dispersants,and solvents.The half-sandwich Cp＊Ir complex （Cp＊ is 1,2,3,4,5-pentamethylcyclopenta-l,3-diene） coordinated by bipyridine ligand bearing both dimethylamino and ortho-hydroxyl groups showed high catalytic activity for the reductive amination of LA.A range of primary amines,such as aromatic and benzyl amines,were readily converted to corresponding pyrrolidinones in good yields.
基金Supported by the Natural Science Foundation of China（No.21402127）. Foundation of Liaoning Province Education Department（No.l,2013381）, PhD Research Startup Foundation of Liaoning Province（No.20131110）, and Career Dcvclopment Support Plan for Young and Middle-aged Teachers in Shenyang Pharmaceutical University.
文摘An efficient phase-transfer-catalyzed directed reductive amination of α-keto esters was described using simple substituted benzyl amines as nitrogen source and K2CO3 as base at room temperature, giving a series of aliphatic a-amino acid derivatives in moderate to high yields（up to 99%）. Preliminary study on this asymmetric process showed that cinchona-derived phase transfer catalyst was elTective, aflbrding the corresponding product in 13% e.e. and 40% yield.
基金the National Natural Science Foundation of China(No.21901107)Shenzhen Bay Laboratory(No.SZBL2019062801006)+5 种基金Shenzhen Science and Technology Innovation Committee(No.KQTD20150717103157174)Key-Area Research and Development Program of Guangdong Province(No.2020B010188001)Stable Support Plan Program of Shenzhen Science and Technology Innovation Committee(No.20200925161222002)Innovative Team of Universities in Guangdong Province(No.2020KCXTD016).G.Q.Chen gratefully acknowledges the National Natural Science Foundation of China(Nos.21901107 and 22171129)the Guangdong Basic and Applied Basic Research Foundation(No.2022B1515020055)the Shenzhen Science and Technology Innovation Committee(No.JCYJ20210324104202007)for financial support.B.Ma is indebted to the financial support from the National Natural Science Foundation of China(No.22001113)B.Ma is the National Natural Science Foundation of China(No.22001113).
文摘A highly efficient and enantioselective method for the asymmetric reductive amination ofβ-keto phosphine de-rivatives was disclosed,and the correspondingβ-amino phosphine oxides could be obtained in high yields(up to 97%yield)and excellent enantioselectivities(up to 97%ee).Moreover,the reaction worked well on a gram scale,indicating that our protocol has potential applications in the synthesis of chiral ligands and organocatalysts.
基金This work was supported financially by the National Key R&D Program of China(2018YFB1501500)National Natural Science Foundation of China(51976225).
文摘Since the utilization of abundant biomass to develop advanced materials has become an utmost priority in recent years,we developed two sustainable routes(i.e.,the impregnation method and the one-pot synthesis)to prepare the hydrochar-supported catalysts and tested its catalytic performance on the reductive amination.Several techniques,such as TEM,XRD and XPS,were adopted to characterize the structural and catalytic features of samples.Results indicated that the impregnation method favors the formation of outer-sphere surface complexes with porous structure as well as well-distributed metallic nanoparticles,while the one-pot synthesis tends to form the inner-sphere surface complexes with relatively smooth appearance and amorphous metals.This difference explains the better activity of catalysts prepared by the impregnation method which can selectively convert benzaldehyde to benzylamine with an excellent yield of 93.7%under the optimal reaction conditions;in contrast,the catalyst prepared by the one-pot synthesis only exhibits a low selectivity near to zero.Furthermore,the gram-scale test catalyzed by the same catalysts exhibits a similar yield of benzylamine in comparison to its smaller scale,which is comparable to the previously reported heterogeneous noble-based catalysts.More surprisingly,the prepared catalysts can be expediently recycled by a magnetic bar and remain the satisfying catalytic activity after reusing up to five times.In conclusion,these developed catalysts enable the synthesis of functional amines with excellent selectivity and carbon balance,proving cost-effective and sustainable access to the wide application of reductive amination.
