Electrosynthesis has gained widespread recognition for its extraordinary ability to precisely control the redox process.This outstanding capability enables the direct conversion of non-functionalized substrates into r...Electrosynthesis has gained widespread recognition for its extraordinary ability to precisely control the redox process.This outstanding capability enables the direct conversion of non-functionalized substrates into reactive intermediates by utilizing easily accessible starting materials, eliminating the need for preliminary functionalization procedures and allowing for unconventional bond activations.展开更多
The precise construction of chiral molecules is a core research area in chemical science and technology.Among the plethora of reported synthetic methods,asymmetric catalysis has emerged as one of the most efficient an...The precise construction of chiral molecules is a core research area in chemical science and technology.Among the plethora of reported synthetic methods,asymmetric catalysis has emerged as one of the most efficient and direct ways to obtain optically pure chiral compounds.This article mainly reviews the recent progress of asymmetric catalysis made by Chinese chemists from the following aspects:the development of new chiral ligands,transition metal-catalyzed asymmetric reactions,asymmetric organocatalytic reactions,and new strategies for asymmetric catalysis.This review does not intend to be comprehensive;only representative examples are selected to highlight the important progress made in this field.Finally,a brief outlook is given on the development of novel chiral ligands/catalysts,new enantioselective reactions,and their applications in chiral drugs and agricultural chemicals.展开更多
Catalysts and ligands possessing the great ability to tolerate over a wide range of mechanistically unrelated reactions are remarked as"privileged",which are rather scarce but extremely meaningful in asymmet...Catalysts and ligands possessing the great ability to tolerate over a wide range of mechanistically unrelated reactions are remarked as"privileged",which are rather scarce but extremely meaningful in asymmetric catalysis.Feng and co-workers have developed a library of conformationally flexible,C2-symmetric N,N'-dioxide amide compounds with original design and featured structure(named as Feng ligand now).They were initially reported as chiral organocatalysts in 2005 and have been further developed as a new class of privileged chiral ligands since 2006.Tremendous success,including versatile coordination chemistry with plenty of metal sources(main-group metals,transition metals,and rare-earth metals),a truly broad scope of asymmetric reactions(more than 50 types),diverse areas of catalysis(organocatalysis,Lewis-acid catalysis,bimetallic relay catalysis,and photocatalysis),numerous synthetic applications of bioactive compounds,has been achieved using Feng N,N'-dioxide.Besides,they demonstrate that chiral ligands with conformationally flexible property can offer excellent chiral environment as well,which challenges the conventional idea preferring rigid structures in the design of chiral ligands.Herein,we briefly introduced the discovery of Feng ligand and the millstones during the development.We also covered the successful applications of Feng ligand by other scientists as well as novel chiral ligands inspired by them.展开更多
Covalent organic frameworks(COFs), covalently assembled from the condensation reactions of organic building blocks, are a fascinating class of functional porous materials with two-or three-dimensional crystalline orga...Covalent organic frameworks(COFs), covalently assembled from the condensation reactions of organic building blocks, are a fascinating class of functional porous materials with two-or three-dimensional crystalline organic structures. Generally, it is preferable to use symmetric and rigid building blocks to construct highly crystalline COFs with desired topology. On the other hand, the incorporation of chiral functional moieties in the building blocks would open up new applications such as asymmetric catalysis and chiral separation. This mini review highlights the principle strategies in the design and synthesis of chiral COFs. The interesting and potential applications of these chiral COFs for asymmetric catalysis and chiral separation are also summarized.This mini review aims to provide an up-to-date advancement of chiral COFs for asymmetric catalysis and chiral separation.展开更多
The asymmetric photocatalytic organic synthesis(APOS)process is a sustainable and environmentally benign method for the production of optically active chemicals with sunlight as an energy source.However,it still lacks...The asymmetric photocatalytic organic synthesis(APOS)process is a sustainable and environmentally benign method for the production of optically active chemicals with sunlight as an energy source.However,it still lacks efficient semiconductors with tunable band structures and has a low recycling stability.Herein,we report the synthesis of tetrahydroquinoline-linked covalent organic frameworks(QH-COFs)with irreversible tetrahydroquinoline linkage as efficient semiconductors for the visible-light-driven asymmetricα-alkylation of aldehydes by merging with a chiral secondary amine.Up to 94%ee was obtained over QH-COFs,and the activity of QH-COFs was significantly higher than those of inorganic semiconductors(e.g.,Ti O2,Bi VO4,and WO3)under similar conditions,which is mainly attributed to their narrow band gap and suitable band edge.As far as we know,QH-COFs are the most active semiconductors for asymmetricα-alkylation of aldehydes ever reported.The QH-COFs were prepared via a one-pot Povarov cascade imine formation and cycloaddition reaction using Sc(OTf)3/Yb(OTf)3 as Lewis acid catalysts.Attributed to the tetrahydroquinoline linkage,QH-COFs showed extremely high recycling stability,which made practicals application possible.This work not only opens up a new avenue for asymmetric photocatalysis but also provides an efficient and general method for the construction of robust COFs.展开更多
Tetracyclic coumarins are a class of important compounds with diverse and superior pharmacolog‐ical activities.However,a direct stereoselective method from simple and readily‐made coumarins derivatives remains chall...Tetracyclic coumarins are a class of important compounds with diverse and superior pharmacolog‐ical activities.However,a direct stereoselective method from simple and readily‐made coumarins derivatives remains challenging due to the inertness of coumarins as dienophiles.Herein,we de‐velop a decarboxylative asymmetric[4+2]cycloaddition of 3‐cyanocoumarins with vinyl benzoxa‐zinones,affording the coumarin‐derived condensed rings bearing three continuous stereocenters in high yields with excellent diastereoselectivities(>20/1 d.r.)and enantioselectivities(up to 99%ee).This direct enantioselective reaction was achieved by a Pd(0)/Cu(I)bimetallic catalytic system.The mechanism studies indicated that the synergistic activation effect,in which chiral Cu(I)as an availa‐ble Lewis acid catalyst activates 3‐cyanocoumarin and chiral Pd(0)complex activates benzoxazi‐none by the formation ofπ‐allyl‐palladium intermediate,plays an important role on the stereoselec‐tive control.The current work provides a new activation modes of Cu catalyst in the Pd/Cu bimetal‐lic catalytic system.展开更多
Asymmetric catalysis has continued to enable the preparation of optically active natural products over the past decade.This minireview summarizes progress in the catalytic enantioselective total synthesis of complex m...Asymmetric catalysis has continued to enable the preparation of optically active natural products over the past decade.This minireview summarizes progress in the catalytic enantioselective total synthesis of complex monoterpenoid indole alkaloids covering the reports from 2019 to June 2021.In particular,the generation of the key chiral stereogenic centers with metal catalysts and organocatalysts has been highlighted,showcasing the power of asymmetric catalysis protocols in accessing complex molecular architectures.展开更多
Chiral benzothiazepines constitute the core structures of many foremost pharmaceuticals with diverse biological activities endowed by their unique scaffolds,which poses a great challenge to organic chemists and pharma...Chiral benzothiazepines constitute the core structures of many foremost pharmaceuticals with diverse biological activities endowed by their unique scaffolds,which poses a great challenge to organic chemists and pharmaceutical researchers.This review provides a concise overview for the asymmetric synthesis of chiral benzothiazepine derivatives,focusing on advances in asymmetric catalysis,including metal catalysis,small-molecule organocatalysis and enzymatic catalysis.The catalytic asymmetric reactions,involving asymmetric epoxidation,reduction,dihydroxylation,hydrogenation,aldol reaction and other sulfa-Michael addition,have emerged as powerful strategies for the rapid construction of chiral benzothiazepine through single or multistep reactions.The booming asymmetric synthetic methodology affords us instructive clues for the highly efficient preparation of chiral benzothiazepines,facilitating their large-scale preparation and diversity-oriented synthesis.展开更多
An operationally simple protocol was designed for the enantioselective silane reduction (ESR) of ketones using air- and moisture-stable [Ir(OMe)(cod)]<sub>2</sub> (cod = 1,5-cyclooctadiene) (3) as a metal ...An operationally simple protocol was designed for the enantioselective silane reduction (ESR) of ketones using air- and moisture-stable [Ir(OMe)(cod)]<sub>2</sub> (cod = 1,5-cyclooctadiene) (3) as a metal catalyst precursor. This reaction was driven by chiral hydroxyamide-functionalized azolium salt 2. The catalytic ESR reaction could be performed under benchtop conditions at room temperature. Treatment of 2 with 3 in THF yielded the monodentate IrCl(NHC)(cod) (NHC = N-heterocyclic carbene) complex 4 in 93% yield, herein the anionic methoxy ligand of 3 serves as an internal base that deprotonates the azolium ring of 2. The well-defined Ir complex 4 catalyzed the ESR reaction of propiophenone (6) with (EtO)<sub>2</sub>MeSiH using the pre-mixing reaction procedure. Based on this success, the catalytic ESR reaction was designed and implemented using an in situ-generated NHC/Ir catalyst derived from 2 and 3. Thus, a wide variety of aryl ketones could be reduced to the corresponding optically active alcohols in moderate to excellent stereoselectivities at room temperature without temperature control. Since the high catalytic activity of 3 was observed, we next evaluated several other transition metal catalyst precursors for the catalytic ESR reaction under the influence of 2. This evaluation revealed that Ir(acac)(cod) (acac = acetylacetonate) (28) and [IrCl(cod)]<sub>2</sub> (5) can be successfully used as metal catalyst precursors in the ESR reaction.展开更多
An asymmetric catalytic strategy in photocatalysis utilizing a chirality-induced approach through an organocatalytic/photoredox relay catalysis strategy is successfully achieved for the rapid construction of polycycli...An asymmetric catalytic strategy in photocatalysis utilizing a chirality-induced approach through an organocatalytic/photoredox relay catalysis strategy is successfully achieved for the rapid construction of polycyclic compounds containing vicinal amino alcohols in a one-pot protocol. This methodology facilitates the efficient synthesis of diverse substituted polycyclic tetrahydroquinoline and benzofuran-derived vicinal amino alcohols, each containing five consecutive chiral centers, with high yields,excellent diastereoselectivities and enantioselectivities(up to 95% yield, >20:1 dr and 98% ee), under mild reaction conditions driven by sequential bifunctional squaramide organocatalyst-catalyzed [4+2] annulation and photocatalyst-catalyzed ketyl radical addition cyclization reaction process. Furthermore, investigations into the stereoselectivity mechanism and high-resolution mass spectrometry(HRMS) experiments on free radical trapping have provided evidence for elucidating the detailed mechanism of chirality-induced processes and chiral intermediate conversions in this procedure.展开更多
Developing chiral solid catalysts for asymmetric catalysis is desirable for the elimination of homogeneous catalysis flaws but remains an immense challenge.Herein,we report the immobilization of TsDPEN on SBA‐15 with...Developing chiral solid catalysts for asymmetric catalysis is desirable for the elimination of homogeneous catalysis flaws but remains an immense challenge.Herein,we report the immobilization of TsDPEN on SBA‐15 with an ionic liquid(IL)linkage via the one‐pot reaction of imidazole‐TsDPEN‐N‐Boc with 3‐(trimethoxysilyl)propyl bromide in the SBA‐15 mesopores.After coordination to Rh,the chiral solid catalysts could efficiently catalyze quinoline transfer hydrogenation,achieving 97%conversion with 93%ee,which was comparable to their homogeneous counterparts.The chiral solid catalyst with the IL linkage afforded much higher turnover frequency than that without the IL linkage(93 h^(–1)vs.33 h^(–1)),attributed to the phase transfer and formate‐enriching ability of the IL linkage.Furthermore,the effect of the pH on the reaction rate of the solid catalyst was investigated,preventing reaction rate retardation during the catalytic process.The tuning of the linkage group is an efficient approach for catalytic activity improvement of immobilized chiral catalysts.展开更多
Immobilizing chiral 1,1＇-bi-2-naphthol （BINOL） in one step onto polymer backbone via stable carbon-carbon bond through Suzuki reaction was achieved. The application of this immobilized chiral BINOL to the catalytic...Immobilizing chiral 1,1＇-bi-2-naphthol （BINOL） in one step onto polymer backbone via stable carbon-carbon bond through Suzuki reaction was achieved. The application of this immobilized chiral BINOL to the catalytic asymmetric oxidation of sulfide to sulfoxide exhibited good activity （up to 60% yield） and high enantioselectivity （up to 89% ee）. The immobilized chiral catalyst was very stable and could be readily reused for over 5 times without significant loss of catalytic activity and enantioselectivity.展开更多
Three diphosphinites were synthesized for preparing rhodium-diphosphinite complexes. The complexes were used for asymmetric catalytic hydrogenation of amino acid precursor alpha-acetamidocinnamic acid and its methyl e...Three diphosphinites were synthesized for preparing rhodium-diphosphinite complexes. The complexes were used for asymmetric catalytic hydrogenation of amino acid precursor alpha-acetamidocinnamic acid and its methyl ester. With all complexes, D-amino acid is the most abundant product.展开更多
A homochrial manganese（Ⅲ） complex（1） derived from chiral salen ligand（1 R,2 R）-（-）-1,2-diphenylethane-1,2-diamine-N,N？-bicarboxyl-salicylidene） has been synthesized through solvothermal procedure and charac...A homochrial manganese（Ⅲ） complex（1） derived from chiral salen ligand（1 R,2 R）-（-）-1,2-diphenylethane-1,2-diamine-N,N？-bicarboxyl-salicylidene） has been synthesized through solvothermal procedure and characterized by IR,elemental analysis,TGA,circular dichroism（CD）,powder and single-crystal X-ray crystallography.It crystallizes in orthorhombic,space group P212121 with a = 9.108（3）,b = 16.431（5）,c = 26.531（6） A,V = 3970.4（19） A^3,Z = 4,Dc = 1.248 g/cm^3,F（000） = 1568,Mr = 745.73,μ = 0.383 mm^-1,the final GOOF = 0.957,R = 0.0631 and wR = 0.1079 for 13250 observed reflections with I 〉 2σ（I）.The coordination polymer 1 possesses a 1 D infinite zigzag chain architecture constructed by the dicarboxyl-functionalized metallosalen ligand（Mn-salen）,and the polymeric chains are further assembled into a 3D supramolecular network structure via strong intermolecular hydrogen bonding interactions between adjacent zigzag chains.As a heterogeneous catalyst,1 was used as an efficient heterogeneous catalyst for the asymmetric olefin epoxidation.展开更多
New Frechet-type dendritic BINOL ligands bearing several BINOL units at the periphery have been successfully synthesized. The （dendritic BINOL） Ti（IV） complexes were proved to be efficient catalysts for the enanti...New Frechet-type dendritic BINOL ligands bearing several BINOL units at the periphery have been successfully synthesized. The （dendritic BINOL） Ti（IV） complexes were proved to be efficient catalysts for the enantioselective addition of diethylzinc to aromatic aldehydes. Moreover, these ligands could be quantitatively recovered and reused at least five times without a loss of the yield and enantioselectivity.展开更多
Polymer-immobilized catalysis has many advantages such as easy recovery and reuse of catalyst. We prepared three novel chiral 1,1＇-bi-2-naphthol-Ti coordination polymers with properly designed ligands and Ti（O^ipr）...Polymer-immobilized catalysis has many advantages such as easy recovery and reuse of catalyst. We prepared three novel chiral 1,1＇-bi-2-naphthol-Ti coordination polymers with properly designed ligands and Ti（O^ipr）4 under mild conditions. The prepared polymers exhibited good activity and excellent enantioselectivity （over 99%ee） in catalyzing the asymmetric oxidation of sulfides. The bridge linker in the polymer and the reaction solvent noticeably affected the enantioseleetivity. The chiral coordination polymer was very stable and easy to separate from catalyzed reaction systems, with no significant loss of activity or enantioselectivity after reuse for at least ten times. These findings suggest a promising type of catalysts for synthesizing the widely used sulfoxides by asymmetrically oxidizing sulfides.展开更多
The diastereo-and enantioselective tandem cycloisomerization/[4+2]-cycloaddition reaction of cyclopropyl tethered allenyl ketones withα,β-unsaturated carbonyl compounds was realized firstly under mild reaction condi...The diastereo-and enantioselective tandem cycloisomerization/[4+2]-cycloaddition reaction of cyclopropyl tethered allenyl ketones withα,β-unsaturated carbonyl compounds was realized firstly under mild reaction conditions by using bimetallic silver(I)/chiral metal-N,N′-dioxide catalysts,providing a facile and atom-economic route to enantioenriched polysubstituted furopyran derivatives with good results.Possible transition state models were proposed to explain the stereoinduction.展开更多
The privileged C_(2)-symmetric rigid phenol-type ligand is more attractive but challenging in asymmetric catalysis.Herein,we designed and synthesized a class of rigid-featured chiral tridentate Phenol-2NO ligands,that...The privileged C_(2)-symmetric rigid phenol-type ligand is more attractive but challenging in asymmetric catalysis.Herein,we designed and synthesized a class of rigid-featured chiral tridentate Phenol-2NO ligands,that incorporate the advantages of both the phenol skeleton and pyrroloimidazolone-based N-oxide moiety,from readily available L-prolinamides in operationally simple two steps and up to 44%overall yield.More importantly,using an achiral quinoline derivative as an additive,the newly developed Phenol-2NO ligand could serve as the anioic ligand upon deprotonative activation to coordinate to Zn(II)to form a highly enantioselective catalyst for the asymmetric Michael-type Friedel-Crafts alkylation reaction of indoles with 2,3-dioxopyrrolidines.Excellent yields(up to 90%)and high enantioselectivities(up to 99%ee)are obtained for a wide range of substrates under mild conditions.Experiments and DFT calculations revealed the reaction mechanism and the origins of the enantioselectivity.This also represented the first activation of phenol-type ligand/metal complex by an achiral organic base as the additive in asymmetric catalysis.展开更多
The construction of acyclic quaternary carbon stereocenters,which are ubiquitous in many bioactive compounds,pharmaceuticals and natural products,has been a long persuit in synthetic organic chemistry.Among numerous m...The construction of acyclic quaternary carbon stereocenters,which are ubiquitous in many bioactive compounds,pharmaceuticals and natural products,has been a long persuit in synthetic organic chemistry.Among numerous methods,enantioselective nickel-catalysis has attracted incremental attention in recent years.This review summarizes the recent development in the asymmetric strategies,research progress,mechanistic investigations for the generation of acyclic quaternary carbon stereocenters via enantioselective nickel catalysis.展开更多
The development of low-cost,earth-abundant and environmentally benign transition metal catalysts,which can catalyze multiple different types of asymmetric reactions,is an important objective in mod-ern asymmetric cata...The development of low-cost,earth-abundant and environmentally benign transition metal catalysts,which can catalyze multiple different types of asymmetric reactions,is an important objective in mod-ern asymmetric catalysis.Herein we demonstrate that a chiral Ni/P-Phos catalyst achieves three types of asymmetric reactions:allenylic substitution of racemic allenic ethers,1,4-hydroalkylation of prochiral 1,3-enynes and double alkylation of newly designed enynyl ether reagents.Three methods complement each other and produce various axially chiral allene derivatives bearing a pyrazolidine-3,5-dione unit,which is widely present in drugs and biologically active molecules with versatile pharmacological activities.展开更多
基金supported by the National Natural Science Foundation of China(21971227,22222113)CAS Project for Young Scientists in Basic Research(YSBR-054)+1 种基金the Fundamental Research Funds for the Central Universities(WK9990000090,WK9990000111)the Chinese Postdoctoral Science Foundation(2022TQ0324,2023M733376)。
文摘Electrosynthesis has gained widespread recognition for its extraordinary ability to precisely control the redox process.This outstanding capability enables the direct conversion of non-functionalized substrates into reactive intermediates by utilizing easily accessible starting materials, eliminating the need for preliminary functionalization procedures and allowing for unconventional bond activations.
基金supported by major research plan“Precise Construction of Multilevel Chiral Substances”of the National Natural Science Foundation of China(grant nos.91956000,92256000,and 92256303).
文摘The precise construction of chiral molecules is a core research area in chemical science and technology.Among the plethora of reported synthetic methods,asymmetric catalysis has emerged as one of the most efficient and direct ways to obtain optically pure chiral compounds.This article mainly reviews the recent progress of asymmetric catalysis made by Chinese chemists from the following aspects:the development of new chiral ligands,transition metal-catalyzed asymmetric reactions,asymmetric organocatalytic reactions,and new strategies for asymmetric catalysis.This review does not intend to be comprehensive;only representative examples are selected to highlight the important progress made in this field.Finally,a brief outlook is given on the development of novel chiral ligands/catalysts,new enantioselective reactions,and their applications in chiral drugs and agricultural chemicals.
基金The authors acknowledge financial support from Zhejiang University,"1000-Youth Talents Plan"and the Fundamental Research Funds for the Central Universities(2020QNA3004).
文摘Catalysts and ligands possessing the great ability to tolerate over a wide range of mechanistically unrelated reactions are remarked as"privileged",which are rather scarce but extremely meaningful in asymmetric catalysis.Feng and co-workers have developed a library of conformationally flexible,C2-symmetric N,N'-dioxide amide compounds with original design and featured structure(named as Feng ligand now).They were initially reported as chiral organocatalysts in 2005 and have been further developed as a new class of privileged chiral ligands since 2006.Tremendous success,including versatile coordination chemistry with plenty of metal sources(main-group metals,transition metals,and rare-earth metals),a truly broad scope of asymmetric reactions(more than 50 types),diverse areas of catalysis(organocatalysis,Lewis-acid catalysis,bimetallic relay catalysis,and photocatalysis),numerous synthetic applications of bioactive compounds,has been achieved using Feng N,N'-dioxide.Besides,they demonstrate that chiral ligands with conformationally flexible property can offer excellent chiral environment as well,which challenges the conventional idea preferring rigid structures in the design of chiral ligands.Herein,we briefly introduced the discovery of Feng ligand and the millstones during the development.We also covered the successful applications of Feng ligand by other scientists as well as novel chiral ligands inspired by them.
基金supported by the Singapore Academic Research Fund(RG112/15,RG19/16)
文摘Covalent organic frameworks(COFs), covalently assembled from the condensation reactions of organic building blocks, are a fascinating class of functional porous materials with two-or three-dimensional crystalline organic structures. Generally, it is preferable to use symmetric and rigid building blocks to construct highly crystalline COFs with desired topology. On the other hand, the incorporation of chiral functional moieties in the building blocks would open up new applications such as asymmetric catalysis and chiral separation. This mini review highlights the principle strategies in the design and synthesis of chiral COFs. The interesting and potential applications of these chiral COFs for asymmetric catalysis and chiral separation are also summarized.This mini review aims to provide an up-to-date advancement of chiral COFs for asymmetric catalysis and chiral separation.
文摘The asymmetric photocatalytic organic synthesis(APOS)process is a sustainable and environmentally benign method for the production of optically active chemicals with sunlight as an energy source.However,it still lacks efficient semiconductors with tunable band structures and has a low recycling stability.Herein,we report the synthesis of tetrahydroquinoline-linked covalent organic frameworks(QH-COFs)with irreversible tetrahydroquinoline linkage as efficient semiconductors for the visible-light-driven asymmetricα-alkylation of aldehydes by merging with a chiral secondary amine.Up to 94%ee was obtained over QH-COFs,and the activity of QH-COFs was significantly higher than those of inorganic semiconductors(e.g.,Ti O2,Bi VO4,and WO3)under similar conditions,which is mainly attributed to their narrow band gap and suitable band edge.As far as we know,QH-COFs are the most active semiconductors for asymmetricα-alkylation of aldehydes ever reported.The QH-COFs were prepared via a one-pot Povarov cascade imine formation and cycloaddition reaction using Sc(OTf)3/Yb(OTf)3 as Lewis acid catalysts.Attributed to the tetrahydroquinoline linkage,QH-COFs showed extremely high recycling stability,which made practicals application possible.This work not only opens up a new avenue for asymmetric photocatalysis but also provides an efficient and general method for the construction of robust COFs.
文摘Tetracyclic coumarins are a class of important compounds with diverse and superior pharmacolog‐ical activities.However,a direct stereoselective method from simple and readily‐made coumarins derivatives remains challenging due to the inertness of coumarins as dienophiles.Herein,we de‐velop a decarboxylative asymmetric[4+2]cycloaddition of 3‐cyanocoumarins with vinyl benzoxa‐zinones,affording the coumarin‐derived condensed rings bearing three continuous stereocenters in high yields with excellent diastereoselectivities(>20/1 d.r.)and enantioselectivities(up to 99%ee).This direct enantioselective reaction was achieved by a Pd(0)/Cu(I)bimetallic catalytic system.The mechanism studies indicated that the synergistic activation effect,in which chiral Cu(I)as an availa‐ble Lewis acid catalyst activates 3‐cyanocoumarin and chiral Pd(0)complex activates benzoxazi‐none by the formation ofπ‐allyl‐palladium intermediate,plays an important role on the stereoselec‐tive control.The current work provides a new activation modes of Cu catalyst in the Pd/Cu bimetal‐lic catalytic system.
基金This work was supported by the National Natural Science Foundation of China(Nos.21732005,21991114,and 21871189)and 111 Project(No.B18035).
文摘Asymmetric catalysis has continued to enable the preparation of optically active natural products over the past decade.This minireview summarizes progress in the catalytic enantioselective total synthesis of complex monoterpenoid indole alkaloids covering the reports from 2019 to June 2021.In particular,the generation of the key chiral stereogenic centers with metal catalysts and organocatalysts has been highlighted,showcasing the power of asymmetric catalysis protocols in accessing complex molecular architectures.
基金The support from the National Natural Science Foundation of China(No.21877087)is greatly appreciated.
文摘Chiral benzothiazepines constitute the core structures of many foremost pharmaceuticals with diverse biological activities endowed by their unique scaffolds,which poses a great challenge to organic chemists and pharmaceutical researchers.This review provides a concise overview for the asymmetric synthesis of chiral benzothiazepine derivatives,focusing on advances in asymmetric catalysis,including metal catalysis,small-molecule organocatalysis and enzymatic catalysis.The catalytic asymmetric reactions,involving asymmetric epoxidation,reduction,dihydroxylation,hydrogenation,aldol reaction and other sulfa-Michael addition,have emerged as powerful strategies for the rapid construction of chiral benzothiazepine through single or multistep reactions.The booming asymmetric synthetic methodology affords us instructive clues for the highly efficient preparation of chiral benzothiazepines,facilitating their large-scale preparation and diversity-oriented synthesis.
文摘An operationally simple protocol was designed for the enantioselective silane reduction (ESR) of ketones using air- and moisture-stable [Ir(OMe)(cod)]<sub>2</sub> (cod = 1,5-cyclooctadiene) (3) as a metal catalyst precursor. This reaction was driven by chiral hydroxyamide-functionalized azolium salt 2. The catalytic ESR reaction could be performed under benchtop conditions at room temperature. Treatment of 2 with 3 in THF yielded the monodentate IrCl(NHC)(cod) (NHC = N-heterocyclic carbene) complex 4 in 93% yield, herein the anionic methoxy ligand of 3 serves as an internal base that deprotonates the azolium ring of 2. The well-defined Ir complex 4 catalyzed the ESR reaction of propiophenone (6) with (EtO)<sub>2</sub>MeSiH using the pre-mixing reaction procedure. Based on this success, the catalytic ESR reaction was designed and implemented using an in situ-generated NHC/Ir catalyst derived from 2 and 3. Thus, a wide variety of aryl ketones could be reduced to the corresponding optically active alcohols in moderate to excellent stereoselectivities at room temperature without temperature control. Since the high catalytic activity of 3 was observed, we next evaluated several other transition metal catalyst precursors for the catalytic ESR reaction under the influence of 2. This evaluation revealed that Ir(acac)(cod) (acac = acetylacetonate) (28) and [IrCl(cod)]<sub>2</sub> (5) can be successfully used as metal catalyst precursors in the ESR reaction.
基金supported by the National Natural Science Foundation of China(21632003,21871116,22071085,U22A20390)the Fundamental Research Funds for the Central Universities(lzujbky-2023-stlt01)the 111 Program from the Ministry of Education of China。
文摘An asymmetric catalytic strategy in photocatalysis utilizing a chirality-induced approach through an organocatalytic/photoredox relay catalysis strategy is successfully achieved for the rapid construction of polycyclic compounds containing vicinal amino alcohols in a one-pot protocol. This methodology facilitates the efficient synthesis of diverse substituted polycyclic tetrahydroquinoline and benzofuran-derived vicinal amino alcohols, each containing five consecutive chiral centers, with high yields,excellent diastereoselectivities and enantioselectivities(up to 95% yield, >20:1 dr and 98% ee), under mild reaction conditions driven by sequential bifunctional squaramide organocatalyst-catalyzed [4+2] annulation and photocatalyst-catalyzed ketyl radical addition cyclization reaction process. Furthermore, investigations into the stereoselectivity mechanism and high-resolution mass spectrometry(HRMS) experiments on free radical trapping have provided evidence for elucidating the detailed mechanism of chirality-induced processes and chiral intermediate conversions in this procedure.
文摘Developing chiral solid catalysts for asymmetric catalysis is desirable for the elimination of homogeneous catalysis flaws but remains an immense challenge.Herein,we report the immobilization of TsDPEN on SBA‐15 with an ionic liquid(IL)linkage via the one‐pot reaction of imidazole‐TsDPEN‐N‐Boc with 3‐(trimethoxysilyl)propyl bromide in the SBA‐15 mesopores.After coordination to Rh,the chiral solid catalysts could efficiently catalyze quinoline transfer hydrogenation,achieving 97%conversion with 93%ee,which was comparable to their homogeneous counterparts.The chiral solid catalyst with the IL linkage afforded much higher turnover frequency than that without the IL linkage(93 h^(–1)vs.33 h^(–1)),attributed to the phase transfer and formate‐enriching ability of the IL linkage.Furthermore,the effect of the pH on the reaction rate of the solid catalyst was investigated,preventing reaction rate retardation during the catalytic process.The tuning of the linkage group is an efficient approach for catalytic activity improvement of immobilized chiral catalysts.
文摘Immobilizing chiral 1,1＇-bi-2-naphthol （BINOL） in one step onto polymer backbone via stable carbon-carbon bond through Suzuki reaction was achieved. The application of this immobilized chiral BINOL to the catalytic asymmetric oxidation of sulfide to sulfoxide exhibited good activity （up to 60% yield） and high enantioselectivity （up to 89% ee）. The immobilized chiral catalyst was very stable and could be readily reused for over 5 times without significant loss of catalytic activity and enantioselectivity.
文摘Three diphosphinites were synthesized for preparing rhodium-diphosphinite complexes. The complexes were used for asymmetric catalytic hydrogenation of amino acid precursor alpha-acetamidocinnamic acid and its methyl ester. With all complexes, D-amino acid is the most abundant product.
基金supported by NSFC-21371119,21431004,21401128,21522104 and 21620102001the National Key Basic Research Program of China(No.2014CB932102 and 2016YFA0203400)the Shanghai“Eastern Scholar”Program
文摘A homochrial manganese（Ⅲ） complex（1） derived from chiral salen ligand（1 R,2 R）-（-）-1,2-diphenylethane-1,2-diamine-N,N？-bicarboxyl-salicylidene） has been synthesized through solvothermal procedure and characterized by IR,elemental analysis,TGA,circular dichroism（CD）,powder and single-crystal X-ray crystallography.It crystallizes in orthorhombic,space group P212121 with a = 9.108（3）,b = 16.431（5）,c = 26.531（6） A,V = 3970.4（19） A^3,Z = 4,Dc = 1.248 g/cm^3,F（000） = 1568,Mr = 745.73,μ = 0.383 mm^-1,the final GOOF = 0.957,R = 0.0631 and wR = 0.1079 for 13250 observed reflections with I 〉 2σ（I）.The coordination polymer 1 possesses a 1 D infinite zigzag chain architecture constructed by the dicarboxyl-functionalized metallosalen ligand（Mn-salen）,and the polymeric chains are further assembled into a 3D supramolecular network structure via strong intermolecular hydrogen bonding interactions between adjacent zigzag chains.As a heterogeneous catalyst,1 was used as an efficient heterogeneous catalyst for the asymmetric olefin epoxidation.
文摘New Frechet-type dendritic BINOL ligands bearing several BINOL units at the periphery have been successfully synthesized. The （dendritic BINOL） Ti（IV） complexes were proved to be efficient catalysts for the enantioselective addition of diethylzinc to aromatic aldehydes. Moreover, these ligands could be quantitatively recovered and reused at least five times without a loss of the yield and enantioselectivity.
基金the Natural Science Foundation of Chongqing Science and Technology Committee (No.2007BB4442)the Science and Technology Research Project of Chongqing Education Commission (No.KJ070402)
文摘Polymer-immobilized catalysis has many advantages such as easy recovery and reuse of catalyst. We prepared three novel chiral 1,1＇-bi-2-naphthol-Ti coordination polymers with properly designed ligands and Ti（O^ipr）4 under mild conditions. The prepared polymers exhibited good activity and excellent enantioselectivity （over 99%ee） in catalyzing the asymmetric oxidation of sulfides. The bridge linker in the polymer and the reaction solvent noticeably affected the enantioseleetivity. The chiral coordination polymer was very stable and easy to separate from catalyzed reaction systems, with no significant loss of activity or enantioselectivity after reuse for at least ten times. These findings suggest a promising type of catalysts for synthesizing the widely used sulfoxides by asymmetrically oxidizing sulfides.
基金supported by the National Natural Science Foundation of China(21890723,22171189)the Fundamental Research Funds for the Central Universities(YJ201819)。
文摘The diastereo-and enantioselective tandem cycloisomerization/[4+2]-cycloaddition reaction of cyclopropyl tethered allenyl ketones withα,β-unsaturated carbonyl compounds was realized firstly under mild reaction conditions by using bimetallic silver(I)/chiral metal-N,N′-dioxide catalysts,providing a facile and atom-economic route to enantioenriched polysubstituted furopyran derivatives with good results.Possible transition state models were proposed to explain the stereoinduction.
基金We thank financial support from NSFC(22061006)Guizhou Provincial Program(GCC[2023]047,GCC[2023]078,ZK[2023]043,ZK[2022]144,ZK[2022]480).
文摘The privileged C_(2)-symmetric rigid phenol-type ligand is more attractive but challenging in asymmetric catalysis.Herein,we designed and synthesized a class of rigid-featured chiral tridentate Phenol-2NO ligands,that incorporate the advantages of both the phenol skeleton and pyrroloimidazolone-based N-oxide moiety,from readily available L-prolinamides in operationally simple two steps and up to 44%overall yield.More importantly,using an achiral quinoline derivative as an additive,the newly developed Phenol-2NO ligand could serve as the anioic ligand upon deprotonative activation to coordinate to Zn(II)to form a highly enantioselective catalyst for the asymmetric Michael-type Friedel-Crafts alkylation reaction of indoles with 2,3-dioxopyrrolidines.Excellent yields(up to 90%)and high enantioselectivities(up to 99%ee)are obtained for a wide range of substrates under mild conditions.Experiments and DFT calculations revealed the reaction mechanism and the origins of the enantioselectivity.This also represented the first activation of phenol-type ligand/metal complex by an achiral organic base as the additive in asymmetric catalysis.
基金National Natural Science Foundation of China(Nos.22278265,U22B20137)Zhejiang Provincial Natural Science Foundation of China(No.LR24B020002)+4 种基金the start-up funding from Hangzhou Normal University(No.4095C50222204165)support.J.S.thanks the Natural Science Foundation of Hunan Province(2024JJ6485)support.J.L.thanks the National Natural Science Foundation of China(22302063)China Postdoctoral Science Foundation(2022M721086)the Natural Science Foundation of Hunan Province(2023JJ40124)for financial support.
文摘The construction of acyclic quaternary carbon stereocenters,which are ubiquitous in many bioactive compounds,pharmaceuticals and natural products,has been a long persuit in synthetic organic chemistry.Among numerous methods,enantioselective nickel-catalysis has attracted incremental attention in recent years.This review summarizes the recent development in the asymmetric strategies,research progress,mechanistic investigations for the generation of acyclic quaternary carbon stereocenters via enantioselective nickel catalysis.
基金supported by the National Natural Science Foundation of China (No.22171240)
文摘The development of low-cost,earth-abundant and environmentally benign transition metal catalysts,which can catalyze multiple different types of asymmetric reactions,is an important objective in mod-ern asymmetric catalysis.Herein we demonstrate that a chiral Ni/P-Phos catalyst achieves three types of asymmetric reactions:allenylic substitution of racemic allenic ethers,1,4-hydroalkylation of prochiral 1,3-enynes and double alkylation of newly designed enynyl ether reagents.Three methods complement each other and produce various axially chiral allene derivatives bearing a pyrazolidine-3,5-dione unit,which is widely present in drugs and biologically active molecules with versatile pharmacological activities.
