Atropisomeric phosphines are crucial for asymmetric catalysis but remain synthetically challenging.Herein,an N-heterocyclic carbene(NHC)catalyzed esterification reaction of dialdehydes with arylboronic acids was devel...Atropisomeric phosphines are crucial for asymmetric catalysis but remain synthetically challenging.Herein,an N-heterocyclic carbene(NHC)catalyzed esterification reaction of dialdehydes with arylboronic acids was developed,successfully constructing the framework of axially chiral phosphorus compounds.Mechanistic studies have revealed that the reaction initially undergoes a desymmetrization process,followed by a kinetic resolution pathway,affording a series of axially chiral phosphorus compounds with high enantioselectivity(up to 92%ee).展开更多
The chemistry of axially chiral compounds has emerged as a subject of increasing interest due to their widespread presence in natural products,bioactive molecules,advanced materials,and chiral ligands/catalysts.On the...The chemistry of axially chiral compounds has emerged as a subject of increasing interest due to their widespread presence in natural products,bioactive molecules,advanced materials,and chiral ligands/catalysts.On the other hand,catalytic asymmetric radical-based transformations provide a complementary platform for the construction of enantiomerically enriched molecules that are in growing demand in the chemical and pharmaceutical in-dustries.In recent years,considerable research efforts have been devoted to the development of catalytic asymmetric radical reactions for the construction of axially chiral compounds based on the unique reactivity modes of diverse radicals.In this review,we critically illustrate these recent achievements according to different radical precursors and catalytic activation modes.Wherever possible,special emphasis is also placed on the discussion of mechanistic features underlying these works and substrate scopes.This review should be of great interest to the experts in this area,but also serve as a helpful starting point for new researchers in this field.展开更多
In this paper,the concept of reversed-or normal-phase chiral stationary phase liquid chromatography has been put forward according to the polar strength of mobile and stationary phases. The statistical model developed...In this paper,the concept of reversed-or normal-phase chiral stationary phase liquid chromatography has been put forward according to the polar strength of mobile and stationary phases. The statistical model developed in HPLC has been used to investigate the separation mechanism of D-and L-enantiomer in chiral stationary phase liquid chromatography.It has been observed that the variation of capacity factor of enantiomers with mobile phase composition in both reversed-phase and normal-phase chiral stationary phase liquid chromatography can be described by the fundamental elution equation lnk'=a+blnC_b+cC_b.The effect of mobile phase composition on the selec- tivity of enantiomers D and L in normal-phase chiral stationary phase liquid chromatography cam be described by the equation lnα=⊿a+⊿blnC_b,but in reversed-phase chiral stationary phase liquid chromatography the selectivity is almost independant of the mobile phase composition.展开更多
Seven 2,2'-bipyridine-based oxazole derivatives have been synthesized through multi-step reactions using 2,2'-bipyridine-3,3'-dicarboxylic acid as raw material.The structures of compounds 1-6 were characte...Seven 2,2'-bipyridine-based oxazole derivatives have been synthesized through multi-step reactions using 2,2'-bipyridine-3,3'-dicarboxylic acid as raw material.The structures of compounds 1-6 were characterized by using 1H NMR,13C NMR,MS,and X-ray single crystal diffraction techniques.The results indicate that only axially chiral enantiomers were observed in the single crystal structures of products 1 and 3 synthesized from achiral amino alcohols;Using racemic amino alcohol((±)-2-aminopropanol)as the raw material,only axial chiral isomers were observed in the single crystal structure of product 2,and no racemic isomer was found.The crystal structure of product 4 based on chiral amino alcohol((S)-valinol)contains non axial chiral isomers and S-type isomers.However,the other two optically pure amino alcohols((S)-phenylpropanol,(R)-phenylpropanol)can only obtain optically pure axially chiral and chiral products 5 and 6,respectively,maintaining the configuration of the raw amino alcohol and no non axial chiral isomer is observed.The product using(±)-2-aminobutanol as the raw material cannot be determined for its absolute configuration as a single crystal of the product has not been obtained.展开更多
Chiral binaphthyl substituents were incorporated onto the phthalocyanine periphery in both homoleptic and heteroleptic bis(phthalocyaninato)terbium single-ion magnets,which exhibit blocking temperatures as high as 15 ...Chiral binaphthyl substituents were incorporated onto the phthalocyanine periphery in both homoleptic and heteroleptic bis(phthalocyaninato)terbium single-ion magnets,which exhibit blocking temperatures as high as 15 K and 28 K,respectively,providing an alternative method towards enhancing the magnetic behavior.展开更多
P-chiral organophosphorus compounds have demonstrated unparalleled application potential in diverse fields,including medicine,agricultural science,material science,and life science.Furthermore,they serve as highly eff...P-chiral organophosphorus compounds have demonstrated unparalleled application potential in diverse fields,including medicine,agricultural science,material science,and life science.Furthermore,they serve as highly effective chiral ligands in both transition metal-catalyzed and organocatalytic asymmetric transformations.In recent years,significant advances have been made in the catalytic asymmetric synthesis of P-chiral organophosphorus compounds,with asymmetric phosphination and hydrophosphination reactions emerging as the dominant strategies.This review systematically summarizes the methodological developments from 2020 to present for constructing P-chiral organophosphorus compounds.The discussion is organized according to different transition metals,aiming to provide a valuable reference and inspiration for researchers in organic synthesis and organophosphorus chemistry.展开更多
The interactions of key lactone chiral compounds(γ-octalactone andγ-undecalactone)in Longjing tea with olfactory receptors(taking OR1A1 as an example)were elucidated through molecular docking and molecular dynamics....The interactions of key lactone chiral compounds(γ-octalactone andγ-undecalactone)in Longjing tea with olfactory receptors(taking OR1A1 as an example)were elucidated through molecular docking and molecular dynamics.The results showed that the thresholds forγ-octalactone,(R)-(+)-γ-octalactone,and(S)-(-)-γ-octalactone were 82μg/L,300μg/L,and 125μg/L,respectively.The thresholds forγ-undecalactone,(R)-(+)-γ-undecalactone and(S)-(-)-γ-undecalactone are 6μg/L,4μg/L,and 10μg/L,respectively.The binding of(S)-(-)-γ-octalactone(-18.389 kJ/mol)to the olfactory receptor OR1A1 is more stable than that of the(R)-(+)-γ-octalactone(-17.280 kJ/mol).On the contrary,(R)-(+)-γ-undecalactone(-19.146 kJ/mol)is binding stability than(S)-(-)-γ-undecalactone(-19.115 kJ/mol).Molecular dynamics simulations imply that the binding of(S)-(-)-γ-octalactone and(R)-(+)-γ-undecalactone to OR1A1 are primarily through polar and hydrogen bonding interactions,whereas(R)-(+)-γ-octalactone and(S)-(-)-γ-undecalactone are relies on hydrophobic interactions.These findings provide scientific support for improving the quality of Longjing tea.展开更多
Asymmetric catalysis represents a cornerstone of chemical research,enabling the efficient and selective synthesis of optically pure chiral compounds from prochiral precursors[1-7].Nonetheless,single-catalyst systems f...Asymmetric catalysis represents a cornerstone of chemical research,enabling the efficient and selective synthesis of optically pure chiral compounds from prochiral precursors[1-7].Nonetheless,single-catalyst systems frequently encounter limitations,including restricted substrate scope and suboptimal efficiency,thereby necessitating the pursuit of alternative strategies.展开更多
Asymmetric synthesis of enantioenriched azo compounds bearing tetrasubstituted stereocenter was achieved through chiral N,N′-dioxide/metal Lewis acid promoted interrupted Japp-Klingemann reaction of aryldiazonium tet...Asymmetric synthesis of enantioenriched azo compounds bearing tetrasubstituted stereocenter was achieved through chiral N,N′-dioxide/metal Lewis acid promoted interrupted Japp-Klingemann reaction of aryldiazonium tetrafluoroborate salts with nucleophiles under mild conditions. This protocol features wide substrate scope and good functional group compatibility.Azaarene-containing chiral azo compounds were stable enough in Japp-Klingemann reaction condition. The key to success of the reaction was the employment of metal salt/N,N′-dioxide ligand and the dual-task roles of the base. Moreover, the X-ray crystal structure of Ni(II)/N,N′-dioxide/substrate complex confirmed that the substrate was activated by bidentate coordination, which shed light on the origin of chiral control of the reaction.展开更多
Stereodivergently constructing the designed products having adjacent multi-stereocenters via a given reaction,with excellent control of both absolute and relative configurations,presents one of the substantial hurdles...Stereodivergently constructing the designed products having adjacent multi-stereocenters via a given reaction,with excellent control of both absolute and relative configurations,presents one of the substantial hurdles in asymmetric catalysis.Herein,we report a precisely stereodivergent asymmetric protocol by synergistic combination of phosphonium-involved ion-pair catalysis and base for accessing to chiral phosphorus compounds bearing two adjacent chiral centers particularly containing an acidic protonated enantioenriched carbon atom,having broad functional group compatibility in both dynamic and thermodynamic processes under mild reaction conditions.Two keys for the success in constructing these stereoisomers with high levels of regio-,diastereo-,and enantioselectivities were contained:firstly,the precise stereo-control in providing dynamic products was enabled by bifunctional phosphonium salt catalyst with semi-enclosed cavity;secondly,the readily stereospecific transformation of adducts from dynamic to thermodynamic version was initiated by achiral base.All four stereoisomers could be readily accessed even in gram-scale in high yields with maintaining excellent stereoselectivities,illustrating the potential of this synergistic catalytic methodology in organic synthesis.Moreover,mechanistic studies including density functional theory(DFT)calculations and control experiments provide insights into the mechanism.展开更多
Three solvent-dependent chiral copper（II） compounds, {[Cu2（bzgluO）2（HzO）2]-4HzO}n （1）, {[Cu2（bzgluO）2-（DMSO）2].H2O}, （2） and [Cuz（bzgluO）2（DMF）2], （3） （H2bzgluO=N-benzoyl-L-glutamic acid） have be...Three solvent-dependent chiral copper（II） compounds, {[Cu2（bzgluO）2（HzO）2]-4HzO}n （1）, {[Cu2（bzgluO）2-（DMSO）2].H2O}, （2） and [Cuz（bzgluO）2（DMF）2], （3） （H2bzgluO=N-benzoyl-L-glutamic acid） have been synthe-sized under ambient temperature conditions and characterized by elemental analysis, IR spectra, UV spectra, ther- mogravimetric analysis, powder X-ray diffraction （PXRD） and single-crystal X-ray diffraction. Compounds 1 and 2 both crystallize in the orthorhombic space group P212121. Compound 3 crystallizes in the tetragonal space group P43. Compound 1 exhibits a ladder-like 1D chain structure, which is extended by hydrogen-bonding interactions to form a 3D supramolecular network. Compounds 2 and 3 both give a diamond-like 3D structure. Besides, there are hydrogen-bonding interactions in 2. The structural difference indicates that the solvent system plays a crucial role in modulating structures of coordination compounds. Circular dichroism （CD） and the magnetic properties of the compounds have also been investigated.展开更多
The effects of the chiral substituents attached to silicon on the stereoselectivity of the reactions of C-centered chiral silicon compounds wm examined. The investigation was focused on the asymmetric C—C bond format...The effects of the chiral substituents attached to silicon on the stereoselectivity of the reactions of C-centered chiral silicon compounds wm examined. The investigation was focused on the asymmetric C—C bond formation reaction of chiral allylsilanes and α-silylallyl anions with aldehydes. The functionalities of the substituents on silicon can be manipulated to improve the stereoselectivities of the reactions remote from silicon atom.展开更多
Ten chirai mesogenic compounds containing fluorinated alkyl terminal tails were prepared and characterized by IR, NMR, MS. The phase transition behavior was investigated by DSC and polarized optical microscope. Two-ri...Ten chirai mesogenic compounds containing fluorinated alkyl terminal tails were prepared and characterized by IR, NMR, MS. The phase transition behavior was investigated by DSC and polarized optical microscope. Two-ring liquid crystal compounds exhibited no mesogenic phase or only a monotropic smectic A phase. The longer fluori- natal alkyl chain on the three-ring was advantageous to the formation of smectic phase. The mesogens with chiral center located between fluorinated tail and mesogenic core exhibited chiral smectic C phase and other smectic phases when the alkoxyl adhering to the other side of the mesogenic core was of intermediate length.展开更多
Crystals of the chiral malic acid hydrate (C_4H_6O_5·H_2O) were unexpectedlyobtained from an ethanol/water solution containing racemic D, L-malic acid and L-asparagine. Thecrystal belongs to orthorhombic space gr...Crystals of the chiral malic acid hydrate (C_4H_6O_5·H_2O) were unexpectedlyobtained from an ethanol/water solution containing racemic D, L-malic acid and L-asparagine. Thecrystal belongs to orthorhombic space group P2_12_12_1 with cell dimensions of a = 0.5576(1), b =0.9818(2), c = 1.1793(2) nm, V = 0.6455(2) nm^3, Z = 4, μ(Mo K_a) =0.152 mm^(-1), F(000) = 320, D_c= 1.565 g·cm^(-3), R=0.051, wR = 0.136 for 657 observed reflections [ I > 2σ(I) ]. Thesignificant difference in bond distances for carboxyl groups suggests that the crystal consist ofmalate anion and protonized crystalline water. This is a report for direct separation of racemicmixture, i.e., without the formation of a molecular complex of raceme with a chiral separatingreagent.展开更多
Chiral phosphine-containing skeletons play a pivotal role in bioactive natural products, pharmaceuticals, chiral catalysts, and ligands. Despite considerable progress has been made in the synthesis of chiral phosphoru...Chiral phosphine-containing skeletons play a pivotal role in bioactive natural products, pharmaceuticals, chiral catalysts, and ligands. Despite considerable progress has been made in the synthesis of chiral phosphorus compounds, the development of facile and modular methods to access chiral allylic phosphorus compounds remains challenging due to the simultaneous control required for reactivity, enantioselectivity, and stereoselectivity. Herein, we present a general and modular platform to achieve the asymmetric reductive cross-coupling of α-bromophosphonates and vinyl bromides, enabling the synthesis of highly valuable chiral allylic phosphonate products with remarkable yields, enantioselectivities, and stereoselectivities.展开更多
The direct C(sp^(3))-H functionalization of abundant hydrocarbons for enantioselective synthesis of high-value chiral compounds has attracted significant attention from both academia and industry. This method is highl...The direct C(sp^(3))-H functionalization of abundant hydrocarbons for enantioselective synthesis of high-value chiral compounds has attracted significant attention from both academia and industry. This method is highly regarded for its inherent atom and step economy as well as abundant starting materials [1].展开更多
Organofluorine compounds have consistently played a pivotal role in chemical synthesis,materials development,and drug discovery.Among these,chiral organofluorine compounds have emerged as a significant focus of resear...Organofluorine compounds have consistently played a pivotal role in chemical synthesis,materials development,and drug discovery.Among these,chiral organofluorine compounds have emerged as a significant focus of research.Gem-difluoroalkenes and difluoroenoxysilanes,owing to their high reactivity and modifiability,are extensively employed in the synthesis of chiral organofluorine compounds.This review summarizes recent research progress in the use of these molecules in asymmetric synthesis.Their application in synthesizing biologically active chiral molecules could open new possibilities and lead to unexpected breakthroughs in medicinal chemistry.展开更多
Chiral organosulfur compounds are not only widely distributed in bioactive natural products and pharmaceuticals,but also play a significant role in chiral ligands/catalysts.Throughout the history of synthetic organic ...Chiral organosulfur compounds are not only widely distributed in bioactive natural products and pharmaceuticals,but also play a significant role in chiral ligands/catalysts.Throughout the history of synthetic organic chemistry,chemists have been absorbed in the construction of centrally chiral organosulfur compounds.Nevertheless,there are relatively few reports on installing sulfur functional groups into axially chiral compounds.Atropisomerism is one of the fundamental phenomena in nature,which ubiquitously exists in natural products.After more than a century of development,atropisomers have been designed and extensively applied to pharmaceuticals,functional materials and chiral ligands/catalysts.Due to the importance of chiral sulfurcontaining atropisomers,there is an increasing demand for enantioselective synthesis of them.Recently,a diversity of approaches by C-S bond formations have been established for the construction of enantioenriched sulfur-containing atropisomers,however,there is no comprehensive review to summarize this great progress.In this mini-review,we summarize recent progress in catalytic asymmetric synthesis of sulfur-containing atropisomers by C-S bond formations,which includes sulfur nucleophilic reactions,sulfur electrophilic reactions and sulfur radical reactions.Furthermore,the reaction mechanisms are also discussed.We hope that this mini-review will enable more researchers to further explore this field.展开更多
Rhodium(III)-catalyzed enantioselective C-H indolylization of isoquinolines was developed.The C-H coupling reactions between 1-aryl isoquinoline derivatives and 3-indolylphenyliodonium salts proceeded smoothly in the ...Rhodium(III)-catalyzed enantioselective C-H indolylization of isoquinolines was developed.The C-H coupling reactions between 1-aryl isoquinoline derivatives and 3-indolylphenyliodonium salts proceeded smoothly in the presence of a modified chiral cyclopentadienyl-Rh(III)complex,affording a series of axially chiral indolylated biaryl products in excellent yields and enantioselectivity(up to 98%yield and 95%ee).展开更多
A new organocatalytic enantioselective Michael addition ofα-fluoromalonate to enals has been developed.The process is efficiently catalyzed by readily available chiral diphenylpyrolinol TES ether under mild reaction ...A new organocatalytic enantioselective Michael addition ofα-fluoromalonate to enals has been developed.The process is efficiently catalyzed by readily available chiral diphenylpyrolinol TES ether under mild reaction conditions to afford versatile highly enantioenriched fluorinated aldehydes.展开更多
基金Project supported by the Natural Science Foundation of Henan Province(Nos.232300421234,252300421726)the Leading Talents in Scientific and Technological Innovation in Shangqiu(No.SQRC202212004)the Program of Ecological Environmental Protection in the Area of Old Course of Yellow River of Shangqiu Normal University。
文摘Atropisomeric phosphines are crucial for asymmetric catalysis but remain synthetically challenging.Herein,an N-heterocyclic carbene(NHC)catalyzed esterification reaction of dialdehydes with arylboronic acids was developed,successfully constructing the framework of axially chiral phosphorus compounds.Mechanistic studies have revealed that the reaction initially undergoes a desymmetrization process,followed by a kinetic resolution pathway,affording a series of axially chiral phosphorus compounds with high enantioselectivity(up to 92%ee).
基金the NationalNatural Science Foundation of China(Nos.21820102003,91956201,21901081,22171099)the Open Research Fund of the School of Chemistry and Chemical Engineering,the Henan Normal University(No.2021YB02)+1 种基金the Program of Introducing Talents of Discipline to Universities of China(No.B17019)the Excellent Doctoral DissertationCultivation Grant to D.L.from Central China Normal University(CCNU).
文摘The chemistry of axially chiral compounds has emerged as a subject of increasing interest due to their widespread presence in natural products,bioactive molecules,advanced materials,and chiral ligands/catalysts.On the other hand,catalytic asymmetric radical-based transformations provide a complementary platform for the construction of enantiomerically enriched molecules that are in growing demand in the chemical and pharmaceutical in-dustries.In recent years,considerable research efforts have been devoted to the development of catalytic asymmetric radical reactions for the construction of axially chiral compounds based on the unique reactivity modes of diverse radicals.In this review,we critically illustrate these recent achievements according to different radical precursors and catalytic activation modes.Wherever possible,special emphasis is also placed on the discussion of mechanistic features underlying these works and substrate scopes.This review should be of great interest to the experts in this area,but also serve as a helpful starting point for new researchers in this field.
基金This work was supported by the National Natural Science Foundation of China.
文摘In this paper,the concept of reversed-or normal-phase chiral stationary phase liquid chromatography has been put forward according to the polar strength of mobile and stationary phases. The statistical model developed in HPLC has been used to investigate the separation mechanism of D-and L-enantiomer in chiral stationary phase liquid chromatography.It has been observed that the variation of capacity factor of enantiomers with mobile phase composition in both reversed-phase and normal-phase chiral stationary phase liquid chromatography can be described by the fundamental elution equation lnk'=a+blnC_b+cC_b.The effect of mobile phase composition on the selec- tivity of enantiomers D and L in normal-phase chiral stationary phase liquid chromatography cam be described by the equation lnα=⊿a+⊿blnC_b,but in reversed-phase chiral stationary phase liquid chromatography the selectivity is almost independant of the mobile phase composition.
基金supported by Guizhou Province College Students Innovation Project(S202310666114)the Student Program of Minzu Normal University of Xingyi(23XYXS28)Guizhou Province Qianxinan Prefecture Science and Technology Bureau project(2022-1-24).
文摘Seven 2,2'-bipyridine-based oxazole derivatives have been synthesized through multi-step reactions using 2,2'-bipyridine-3,3'-dicarboxylic acid as raw material.The structures of compounds 1-6 were characterized by using 1H NMR,13C NMR,MS,and X-ray single crystal diffraction techniques.The results indicate that only axially chiral enantiomers were observed in the single crystal structures of products 1 and 3 synthesized from achiral amino alcohols;Using racemic amino alcohol((±)-2-aminopropanol)as the raw material,only axial chiral isomers were observed in the single crystal structure of product 2,and no racemic isomer was found.The crystal structure of product 4 based on chiral amino alcohol((S)-valinol)contains non axial chiral isomers and S-type isomers.However,the other two optically pure amino alcohols((S)-phenylpropanol,(R)-phenylpropanol)can only obtain optically pure axially chiral and chiral products 5 and 6,respectively,maintaining the configuration of the raw amino alcohol and no non axial chiral isomer is observed.The product using(±)-2-aminobutanol as the raw material cannot be determined for its absolute configuration as a single crystal of the product has not been obtained.
基金the National Key Basic Research Program of China(Grant No.2013CB933402)the Natural Science Foundation of China(No.21290174,21631003,and 21401009)the China Scholarship Council,University of Science and Technology Beijing is gratefully acknowledged.
文摘Chiral binaphthyl substituents were incorporated onto the phthalocyanine periphery in both homoleptic and heteroleptic bis(phthalocyaninato)terbium single-ion magnets,which exhibit blocking temperatures as high as 15 K and 28 K,respectively,providing an alternative method towards enhancing the magnetic behavior.
基金support from the National Natural Science Foundation of China(Nos.22377097,22074114)the Natural Science Foundation of Hubei Province(No.2024AFB233)+3 种基金the Engineering Research Center of Phosphorus Resources Development and Utilization of Ministry of Education(No.LCX202305)the Science Research Foundation of Hubei Provincial Department of Education(No.Q20221513)the Postdoctoral Innovation Talent Program of Hubei Province(No.2024HBBHCXB074)the Science Foundation of Wuhan Institute of Technology(No.K2023116).
文摘P-chiral organophosphorus compounds have demonstrated unparalleled application potential in diverse fields,including medicine,agricultural science,material science,and life science.Furthermore,they serve as highly effective chiral ligands in both transition metal-catalyzed and organocatalytic asymmetric transformations.In recent years,significant advances have been made in the catalytic asymmetric synthesis of P-chiral organophosphorus compounds,with asymmetric phosphination and hydrophosphination reactions emerging as the dominant strategies.This review systematically summarizes the methodological developments from 2020 to present for constructing P-chiral organophosphorus compounds.The discussion is organized according to different transition metals,aiming to provide a valuable reference and inspiration for researchers in organic synthesis and organophosphorus chemistry.
基金sponsored by the National Natural Science Foundation of China(Grants 32272453)the Science and Technology Project of Guizhou Provincial Company of China Tobacco Corporation(2023XM19)+1 种基金Collaborative Innovation Fund of Shanghai Institute of Technology(XTCX2023-15)Guiyang Technology Innovation Center of Ecological Food(Flavor and Quality)Industry.
文摘The interactions of key lactone chiral compounds(γ-octalactone andγ-undecalactone)in Longjing tea with olfactory receptors(taking OR1A1 as an example)were elucidated through molecular docking and molecular dynamics.The results showed that the thresholds forγ-octalactone,(R)-(+)-γ-octalactone,and(S)-(-)-γ-octalactone were 82μg/L,300μg/L,and 125μg/L,respectively.The thresholds forγ-undecalactone,(R)-(+)-γ-undecalactone and(S)-(-)-γ-undecalactone are 6μg/L,4μg/L,and 10μg/L,respectively.The binding of(S)-(-)-γ-octalactone(-18.389 kJ/mol)to the olfactory receptor OR1A1 is more stable than that of the(R)-(+)-γ-octalactone(-17.280 kJ/mol).On the contrary,(R)-(+)-γ-undecalactone(-19.146 kJ/mol)is binding stability than(S)-(-)-γ-undecalactone(-19.115 kJ/mol).Molecular dynamics simulations imply that the binding of(S)-(-)-γ-octalactone and(R)-(+)-γ-undecalactone to OR1A1 are primarily through polar and hydrogen bonding interactions,whereas(R)-(+)-γ-octalactone and(S)-(-)-γ-undecalactone are relies on hydrophobic interactions.These findings provide scientific support for improving the quality of Longjing tea.
基金supported by the National Key R&D Program of China(2022YFA1503300)the National Natural Science Foundation of China(Grant no.22471273)。
文摘Asymmetric catalysis represents a cornerstone of chemical research,enabling the efficient and selective synthesis of optically pure chiral compounds from prochiral precursors[1-7].Nonetheless,single-catalyst systems frequently encounter limitations,including restricted substrate scope and suboptimal efficiency,thereby necessitating the pursuit of alternative strategies.
基金supported by the National Natural Science Foundation of China(21890723,21921002)。
文摘Asymmetric synthesis of enantioenriched azo compounds bearing tetrasubstituted stereocenter was achieved through chiral N,N′-dioxide/metal Lewis acid promoted interrupted Japp-Klingemann reaction of aryldiazonium tetrafluoroborate salts with nucleophiles under mild conditions. This protocol features wide substrate scope and good functional group compatibility.Azaarene-containing chiral azo compounds were stable enough in Japp-Klingemann reaction condition. The key to success of the reaction was the employment of metal salt/N,N′-dioxide ligand and the dual-task roles of the base. Moreover, the X-ray crystal structure of Ni(II)/N,N′-dioxide/substrate complex confirmed that the substrate was activated by bidentate coordination, which shed light on the origin of chiral control of the reaction.
基金supported by the National Natural Science Foundation of China(21971165,21921002)the National Key R&D Program of China(2018YFA0903500)+3 种基金the“1000-Youth Talents Program”(YJ201702)the Fundamental Research Funds from Sichuan University(2020SCUNL108)Beijing National Laboratory for Molecular Sciences(BNLMS202101)the Fundamental Research Funds for the Central Universities。
文摘Stereodivergently constructing the designed products having adjacent multi-stereocenters via a given reaction,with excellent control of both absolute and relative configurations,presents one of the substantial hurdles in asymmetric catalysis.Herein,we report a precisely stereodivergent asymmetric protocol by synergistic combination of phosphonium-involved ion-pair catalysis and base for accessing to chiral phosphorus compounds bearing two adjacent chiral centers particularly containing an acidic protonated enantioenriched carbon atom,having broad functional group compatibility in both dynamic and thermodynamic processes under mild reaction conditions.Two keys for the success in constructing these stereoisomers with high levels of regio-,diastereo-,and enantioselectivities were contained:firstly,the precise stereo-control in providing dynamic products was enabled by bifunctional phosphonium salt catalyst with semi-enclosed cavity;secondly,the readily stereospecific transformation of adducts from dynamic to thermodynamic version was initiated by achiral base.All four stereoisomers could be readily accessed even in gram-scale in high yields with maintaining excellent stereoselectivities,illustrating the potential of this synergistic catalytic methodology in organic synthesis.Moreover,mechanistic studies including density functional theory(DFT)calculations and control experiments provide insights into the mechanism.
文摘Three solvent-dependent chiral copper（II） compounds, {[Cu2（bzgluO）2（HzO）2]-4HzO}n （1）, {[Cu2（bzgluO）2-（DMSO）2].H2O}, （2） and [Cuz（bzgluO）2（DMF）2], （3） （H2bzgluO=N-benzoyl-L-glutamic acid） have been synthe-sized under ambient temperature conditions and characterized by elemental analysis, IR spectra, UV spectra, ther- mogravimetric analysis, powder X-ray diffraction （PXRD） and single-crystal X-ray diffraction. Compounds 1 and 2 both crystallize in the orthorhombic space group P212121. Compound 3 crystallizes in the tetragonal space group P43. Compound 1 exhibits a ladder-like 1D chain structure, which is extended by hydrogen-bonding interactions to form a 3D supramolecular network. Compounds 2 and 3 both give a diamond-like 3D structure. Besides, there are hydrogen-bonding interactions in 2. The structural difference indicates that the solvent system plays a crucial role in modulating structures of coordination compounds. Circular dichroism （CD） and the magnetic properties of the compounds have also been investigated.
文摘The effects of the chiral substituents attached to silicon on the stereoselectivity of the reactions of C-centered chiral silicon compounds wm examined. The investigation was focused on the asymmetric C—C bond formation reaction of chiral allylsilanes and α-silylallyl anions with aldehydes. The functionalities of the substituents on silicon can be manipulated to improve the stereoselectivities of the reactions remote from silicon atom.
文摘Ten chirai mesogenic compounds containing fluorinated alkyl terminal tails were prepared and characterized by IR, NMR, MS. The phase transition behavior was investigated by DSC and polarized optical microscope. Two-ring liquid crystal compounds exhibited no mesogenic phase or only a monotropic smectic A phase. The longer fluori- natal alkyl chain on the three-ring was advantageous to the formation of smectic phase. The mesogens with chiral center located between fluorinated tail and mesogenic core exhibited chiral smectic C phase and other smectic phases when the alkoxyl adhering to the other side of the mesogenic core was of intermediate length.
文摘Crystals of the chiral malic acid hydrate (C_4H_6O_5·H_2O) were unexpectedlyobtained from an ethanol/water solution containing racemic D, L-malic acid and L-asparagine. Thecrystal belongs to orthorhombic space group P2_12_12_1 with cell dimensions of a = 0.5576(1), b =0.9818(2), c = 1.1793(2) nm, V = 0.6455(2) nm^3, Z = 4, μ(Mo K_a) =0.152 mm^(-1), F(000) = 320, D_c= 1.565 g·cm^(-3), R=0.051, wR = 0.136 for 657 observed reflections [ I > 2σ(I) ]. Thesignificant difference in bond distances for carboxyl groups suggests that the crystal consist ofmalate anion and protonized crystalline water. This is a report for direct separation of racemicmixture, i.e., without the formation of a molecular complex of raceme with a chiral separatingreagent.
基金supported by the National Natural Science Foundation of China (22071183)the Science and Technology Commission of Shanghai Municipality (19DZ2271500)。
文摘Chiral phosphine-containing skeletons play a pivotal role in bioactive natural products, pharmaceuticals, chiral catalysts, and ligands. Despite considerable progress has been made in the synthesis of chiral phosphorus compounds, the development of facile and modular methods to access chiral allylic phosphorus compounds remains challenging due to the simultaneous control required for reactivity, enantioselectivity, and stereoselectivity. Herein, we present a general and modular platform to achieve the asymmetric reductive cross-coupling of α-bromophosphonates and vinyl bromides, enabling the synthesis of highly valuable chiral allylic phosphonate products with remarkable yields, enantioselectivities, and stereoselectivities.
文摘The direct C(sp^(3))-H functionalization of abundant hydrocarbons for enantioselective synthesis of high-value chiral compounds has attracted significant attention from both academia and industry. This method is highly regarded for its inherent atom and step economy as well as abundant starting materials [1].
基金support from the Sichuan University of Science&Engineering(2024RC042)and HKBU RC-SFCRG/23-24 for financial support.
文摘Organofluorine compounds have consistently played a pivotal role in chemical synthesis,materials development,and drug discovery.Among these,chiral organofluorine compounds have emerged as a significant focus of research.Gem-difluoroalkenes and difluoroenoxysilanes,owing to their high reactivity and modifiability,are extensively employed in the synthesis of chiral organofluorine compounds.This review summarizes recent research progress in the use of these molecules in asymmetric synthesis.Their application in synthesizing biologically active chiral molecules could open new possibilities and lead to unexpected breakthroughs in medicinal chemistry.
基金supported by the National Natural Science Foundation of China (22071149,21871178)the Natural Science Foundation of Shanghai (23ZR1428200)the Program for Professor of Special Appointment (Eastern Scholar)at Shanghai Institutions of Higher Learning。
文摘Chiral organosulfur compounds are not only widely distributed in bioactive natural products and pharmaceuticals,but also play a significant role in chiral ligands/catalysts.Throughout the history of synthetic organic chemistry,chemists have been absorbed in the construction of centrally chiral organosulfur compounds.Nevertheless,there are relatively few reports on installing sulfur functional groups into axially chiral compounds.Atropisomerism is one of the fundamental phenomena in nature,which ubiquitously exists in natural products.After more than a century of development,atropisomers have been designed and extensively applied to pharmaceuticals,functional materials and chiral ligands/catalysts.Due to the importance of chiral sulfurcontaining atropisomers,there is an increasing demand for enantioselective synthesis of them.Recently,a diversity of approaches by C-S bond formations have been established for the construction of enantioenriched sulfur-containing atropisomers,however,there is no comprehensive review to summarize this great progress.In this mini-review,we summarize recent progress in catalytic asymmetric synthesis of sulfur-containing atropisomers by C-S bond formations,which includes sulfur nucleophilic reactions,sulfur electrophilic reactions and sulfur radical reactions.Furthermore,the reaction mechanisms are also discussed.We hope that this mini-review will enable more researchers to further explore this field.
基金We thank the National Key R&D Program of China(2021YFA1500100)National Natural Science Foundation of China(21821002,92256302,22071260)Science and Technology Commission of Shanghai Municipality(21520780100)for generous financial support.S.-L.Y.thanks the supports from the New Cornerstone ScienceFoundation.
文摘Rhodium(III)-catalyzed enantioselective C-H indolylization of isoquinolines was developed.The C-H coupling reactions between 1-aryl isoquinoline derivatives and 3-indolylphenyliodonium salts proceeded smoothly in the presence of a modified chiral cyclopentadienyl-Rh(III)complex,affording a series of axially chiral indolylated biaryl products in excellent yields and enantioselectivity(up to 98%yield and 95%ee).
基金support for this work provided by the NSF(CHE-0704015)
文摘A new organocatalytic enantioselective Michael addition ofα-fluoromalonate to enals has been developed.The process is efficiently catalyzed by readily available chiral diphenylpyrolinol TES ether under mild reaction conditions to afford versatile highly enantioenriched fluorinated aldehydes.
