Herein,we report the dynamic kinetic resolution asymmetric acylation ofγ-hydroxy-γ-perfluoroalkyl butenolides/phthalides catalyzed by amino acid-derived bifunctional organocatalysts,and a series of ketals were obtai...Herein,we report the dynamic kinetic resolution asymmetric acylation ofγ-hydroxy-γ-perfluoroalkyl butenolides/phthalides catalyzed by amino acid-derived bifunctional organocatalysts,and a series of ketals were obtained in high yields(up to 95%)and excellent enantioselectivities(up to 99%).In terms of synthetic utility,the reaction can be performed on a gram scale,and the product can be converted into potential biological nucleoside analog.展开更多
The enantioselective esterification of racemic 1-trimethylsilylethanol with acids catalyzed by lipase in organic solvent was successfully performed. The influence of some factors on the reaction was investigated. Amon...The enantioselective esterification of racemic 1-trimethylsilylethanol with acids catalyzed by lipase in organic solvent was successfully performed. The influence of some factors on the reaction was investigated. Among the four lipases explored, Candida rugosa lipase (CRL) showed the highest activity and enantioselectivity. Octanoic acid was the best acyl donor among the eleven acids studied and n-hexane was the most suitable medium for the reaction. The optimum shaking rate and temperature were found to be 150r·min-1 and 20℃ to 30℃, respectively. The enantiomeric excess of the remaining (5)-(-)-1-trimethylsilylethanol was 93% when substrate conversion was 53% upon incubation of the reaction mixture at 30℃, 150r·min-1 for 12 h.展开更多
The chiral oxiranecarboxylic acids or esters 2a-e were obtained with lipase (CCL) in aqueous-organic system.The ee and the absolute configurations of the products were determined.
Kinetic resolution is one of the most commonly used methods allowing access to enantioenriched compounds.The last two decades have seen the rapid development of kinetic resolutions enabled by N-heterocyclic carbene ca...Kinetic resolution is one of the most commonly used methods allowing access to enantioenriched compounds.The last two decades have seen the rapid development of kinetic resolutions enabled by N-heterocyclic carbene catalysis,and part of the achievements have been summarized in our previous review paper published in 2017.Since then,a series of new advances have been realized,and this review will provide an update of this field covering reports from mid-2017 to 2023.展开更多
We report here a generic,green synthesis of 17 valuable syn-aryl-(2S,3R)-2–chloro-3–hydroxy esters(syn-(2S,3R)-1)in 73%-99%isolated yields along with 6.1:1–83:1 dr and 31%~>99%ee,through dynamic reductive kineti...We report here a generic,green synthesis of 17 valuable syn-aryl-(2S,3R)-2–chloro-3–hydroxy esters(syn-(2S,3R)-1)in 73%-99%isolated yields along with 6.1:1–83:1 dr and 31%~>99%ee,through dynamic reductive kinetic resolution of racemic arylα–chloroβ-keto esters(2)catalyzed by an engineered ketoreductase which was obtained via ep PCR-based directed evolution.The hectogram scale synthesis of syn-(2S,3R)-1b at a substrate concentration of 120 g/L showcased the application potential of the biocatalytic method developed presently.展开更多
Kinetic resolution of DL-phenylalanine methyl ester was carried out using drimobilized α -chymotrypsin (IC) as catalyst. The effects of temperatUre, pH, concentration of substrate and reactionvessels on the resolutio...Kinetic resolution of DL-phenylalanine methyl ester was carried out using drimobilized α -chymotrypsin (IC) as catalyst. The effects of temperatUre, pH, concentration of substrate and reactionvessels on the resolution were investigated. High quality L-phenylalanine was obtained in good yieldby an IC column.展开更多
The precise synthesis of planar chiral pillar[n]arenes(PAs)faces significant challenges due to their inherent dynamic racemization induced by rapid molecular flipping.To address this issue and enhance conformational s...The precise synthesis of planar chiral pillar[n]arenes(PAs)faces significant challenges due to their inherent dynamic racemization induced by rapid molecular flipping.To address this issue and enhance conformational stability of these macrocycles,we have developed a strategic approach involving the introduction of sterically bulky aryl(sp^(2))substituents at the molecular rims through dynamic kinetic resolution(DKR).A series of robust and chirality-aligned homo-and hetero-diaryl PAs(n=5,6)were achieved with excellent enantioselectivity(>95%ee)via Pd-catalyzed asymmetric Suzuki–Miyaura coupling reactions.Mechanism study revealed axial steric hindrance,rather than radial substitution,governs conformational chirality-locking in pillar[n]arenes.This work not only provides an attractive protocol for the enantioselective synthesis of planar chiral pillar[n]arenes,but also enriches the library of macrocycles for promising applications in chiral molecular machines,enantioselective sensors,and chiral luminescent materials.展开更多
We present here a catalytic enantioconvergent aminationof alcohols for efficient access to chiral C2-and C3-substituted benzomorpholines. The racemicamino alcohol substrates of different substitutionpatterns, which ar...We present here a catalytic enantioconvergent aminationof alcohols for efficient access to chiral C2-and C3-substituted benzomorpholines. The racemicamino alcohol substrates of different substitutionpatterns, which are readily available from a commonprecursor, can be converted to the enantioenrichedheterocycles in a highly atom- and step-economicalfashion. In particular, an unprecedented asymmetricamination of racemic primary alcohols via dynamickinetic resolution is achieved under cooperativeiridium/iron catalysis, resulting in highly enantioenrichedC2-substituted benzomorpholines that aredifficult to access otherwise.展开更多
Comprehensive Summary:New chiral guanidine catalysts having axial chirality containing a methoxy group were synthesized.Subsequently,their catalytic ability was examined by applying the silylative kinetic resolution o...Comprehensive Summary:New chiral guanidine catalysts having axial chirality containing a methoxy group were synthesized.Subsequently,their catalytic ability was examined by applying the silylative kinetic resolution of racemic alcohols using chlorosilanes.Based on an X-ray crystallographic analysis of the catalysts,the functional role of the methoxy group was predicted,and the plausible reaction pathways and a transition state were described.It was also revealed that the existence of hydrogen bonding between the methoxy group on the catalyst and hydrogen atom at C-1 position of the substrates was of great importance for attaining high selectivity and reactivity.The proposed method is applicable to various acyclic aryl,heteroaryl,and normal-alkyl alcohols exhibiting medium to high s-values(s=15-96,15 examples).展开更多
Chirality is a common phenomenon in nature,playing a crucial role in fields such as pharmaceuticals[1],materials science[2],and life sciences[3].The catalytic synthesis of chiral molecules,particularly those bearing m...Chirality is a common phenomenon in nature,playing a crucial role in fields such as pharmaceuticals[1],materials science[2],and life sciences[3].The catalytic synthesis of chiral molecules,particularly those bearing multiple stereogenic elements(e.g.,central,axial,planar,helical,or inherent chirality),has gained tremendous attention in organic synthesis[4].展开更多
Planar organofluorine compounds are highly sought-after structural motifs.Herein,we present an enantioselective strategy for the synthesis of planar chiral fluoroalkenes via kinetic resolution of gem-difluorovinylferr...Planar organofluorine compounds are highly sought-after structural motifs.Herein,we present an enantioselective strategy for the synthesis of planar chiral fluoroalkenes via kinetic resolution of gem-difluorovinylferrocenes by copper-catalyzed hydrodefluorination in the presence of a base and diboron.This method was successfully applied to provide a diverse range of planar chiral gem-difluoroalkenes and Z-monofluoroalkenes with excellent regio-,stereo-and enantioselectivity.The resulting enantioenriched planar chiral fluoroalkenes could undergo various enantioretaining transformations,broadening their synthetic utility.Furthermore,density functional theory(DFT)calculations provide mechanistic insights into the origin of enantioselectivity,enhancing the understanding of this transformation.展开更多
Phosphorus stereocenter,a ubiquitous central chiral element,plays a crucial role in pharmaceuticals,materials science and asymmetric catalysis.As such,stereoselective construction of phosphorus stereocenters has becom...Phosphorus stereocenter,a ubiquitous central chiral element,plays a crucial role in pharmaceuticals,materials science and asymmetric catalysis.As such,stereoselective construction of phosphorus stereocenters has become important in the field of organic synthesis.Herein we report a general and modular method for the construction of P-stereogenic centers via palladium/chiral norbornene cooperative catalysis-enabled desymmetrization/kinetic resolution process.It is a two-component annulation reaction that involves widely available aryl iodides and prochiral or racemic phosphinamides as the reactants.A wide variety of substrates bearing an assortment of functional groups(50 examples)are compatible with this method.Other features include a distinct enantiodiscrimination mechanism,excellent stereoselectivities,and scalability.The obtained chiral P-stereogenic products bear a common C–Br bond,which can be elaborated for the synthesis of new P-stereogenic compounds with diverse structural features.In addition,preliminary studies uncover the promising chiroptical properties of these P-stereogenic cyclic phosphinamides.Density functional theory calculations are performed to reveal that the noncovalent hydrogen bonding interaction is the origin of enantiodiscrimination during the desymmetrization process.展开更多
Bridged biaryl atropisomers are widely recognized as a significant structural motif commonly found in bioactive molecules and natural products.Herein,we report an organocatalytic dynamic kinetic resolution(DKR)approac...Bridged biaryl atropisomers are widely recognized as a significant structural motif commonly found in bioactive molecules and natural products.Herein,we report an organocatalytic dynamic kinetic resolution(DKR)approach for the synthesis of optically pure biaryl-bridged seven-membered lactones.In the presence of a chiral N-heterocyclic carbene(NHC)catalyst,racemic biaryl-bridged hemiacetals,generated in situ from 2’-formyl-2-biphenyl carboxylic acids,undergo stereoselective coupling with NHC-bound acylazolium intermediates derived from NHC and aldehydes.This transformation delivers seven-membered biaryl-bridged lactone products with very high yields and good to excellent regio-and enantioselectivities.展开更多
Recent developments in chirality chemistry have revealed remarkable instances of atropisomers featuring multiple chiral elements.Despite significant progress in the synthesis and application of atropisomers,developing...Recent developments in chirality chemistry have revealed remarkable instances of atropisomers featuring multiple chiral elements.Despite significant progress in the synthesis and application of atropisomers,developing a synthetic protocol for the simultaneous introduction of axial and point chirality is still a fascinating challenge.In this context,we present a convenient and versatile method for synthesizing novel atropisomers with axial and point chirality.This approach,based on a new reaction mechanism with nickel-controlled Si–C bond activation,facilitates the controllable migratory insertion of aldehydes into the Ni–C bond.We utilize multidimensional strategies of desymmetrization,kinetic resolution and dynamic kinetic resolution to complete enantioselective nickel-catalyzed ring expansion of benzosilacyclobutenes with aldehydes.The design of multidimensional kinetic resolution,desymmetrization,and dynamic resolution,features a straightforward catalytic system,mild reaction conditions,and broad functional group tolerances.Various axially chiral biaryl oxasilacycles bearing carbon-or siliconstereogenic centers are obtained with excellent diastereo-and enantio-selectivities(up to>20:1 dr and>99.9%ee)through the use of a chiral Ni complex with a large cavity-type 1,1,4,4-tetra-aryl-2,3-O-isopropylidene-L-threitol(TADDOL)-derived phosphoramidite ligand.展开更多
Asymmetric direct hydrogenation(ADH)is a straightforward and atom-economic methodology to achieve optically active compounds.The synthesis of chiral compounds bearing stereogenic centers has been well established.In c...Asymmetric direct hydrogenation(ADH)is a straightforward and atom-economic methodology to achieve optically active compounds.The synthesis of chiral compounds bearing stereogenic centers has been well established.In contrast,the construction of atropisomers,especially atropisomers bearing multiple chiral elements,has sporadically been explored.Herein,we report an innovative atroposelective iridium-catalyzed hydrogenation of N-arylindole ketones and heterobiaryl ketones via dynamic kinetic resolution(DKR)based on a Lewis acid-base interaction between the nitrogen atom and the carbonyl group of ketones,providing C-N and C-C atropisomers bearing multiple chiral elements with excellent enantioselectivities,diastereoselectivities and yields.The lynchpin of the DKR-ADH process stands in the newly developed planar-chiral tridentate PNO ligand,which ensures the excellent control of enantioselectivity and diastereoselectivity simultaneously.The synthetic utilization of this protocol is proved through stereospecific transformation to a tridentate PNN ligand bearing axial and central chirality,which shows promising potential in iridium-catalyzed asymmetric hydrogenation of simple ketones.展开更多
Asymmetric kinetic resolution polymerization(AKRP)provides an ideal way to obtain highly isotactic polymers and optically pure monomers.However,highly enantioselective AKRP process is still rarely reported to date.And...Asymmetric kinetic resolution polymerization(AKRP)provides an ideal way to obtain highly isotactic polymers and optically pure monomers.However,highly enantioselective AKRP process is still rarely reported to date.And the AKRP of racemic lactide(rac-LA)remains a challenge.Here,in this paper,the AKRP of rac-LA was achieved by means of an enhanced enantiomorphic site control,delivering isotactic polylactide(PLA)and enantiomeric enriched lactide(LA)with the highest kinetic resolution coefficients(k_(rel))to date.Different from common(Salen)Al complex,a series of new chiral(BisSalen)Al complexes were designed and synthesized to form a more confined chiral microenvironment and further improve specific discrimination of rac-LA.The NMR analysis,kinetic studies,the activation parameters and thermal properties of the resulting PLAs provided strong evidence for enhanced enantiomorphic site control.This work enables highly enantioselective AKRP of rac-LA.展开更多
N-heterocyclic carbene-catalyzed enantioselective kinetic resolutions,dynamic kinetic resolutions,and desymmetrization reactions are systematically reviewed.The content is organized according to the activation modes i...N-heterocyclic carbene-catalyzed enantioselective kinetic resolutions,dynamic kinetic resolutions,and desymmetrization reactions are systematically reviewed.The content is organized according to the activation modes involved in these transformations.Future advances within this highly active research field are discussed from our perspectives on the topic.展开更多
An efficient method for asymmetric synthesis of acyclic α-tertiary amine derivatives has been achieved through enantioselective aminations of α-branched ynones with azodicarboxylates enabled by chiral phosphoric aci...An efficient method for asymmetric synthesis of acyclic α-tertiary amine derivatives has been achieved through enantioselective aminations of α-branched ynones with azodicarboxylates enabled by chiral phosphoric acid catalysis.Moreover,kinetic resolution of racemic starting material was realized under these conditions,which gave access to valuable enantioenriched α-substituted ketones.展开更多
An efficient kinetic resolution(KR)protocol for 1,2-diamines has been developed through asymmetric electrophilic aminations of anilines enabled by chiral phosphoric acid catalysis.A wide array of substituted 1,2-diami...An efficient kinetic resolution(KR)protocol for 1,2-diamines has been developed through asymmetric electrophilic aminations of anilines enabled by chiral phosphoric acid catalysis.A wide array of substituted 1,2-diamines were compatible with this method,generating both the recovered staring materials and the amination products with high enantioselectivities(with s-factor up to 218).Notably,this method is amenable to the kinetic resolution of 1,2-diamines bearingα-tertiary amine moieties,which represents the first KR of this type of 1,2-diamines.Facile removal of the introduced hydrazine group and oxidative cleavage of the N-aryl group to release the free primary amine demonstrate the value of this method.展开更多
A highly efficient kinetic resolution of racemic 2-substituted 1,2-dihydroquinolines via Rh-catalyzed asymmetric hydroarylation has been described for the first time.A variety of arylboronic acids coupled with 2-subst...A highly efficient kinetic resolution of racemic 2-substituted 1,2-dihydroquinolines via Rh-catalyzed asymmetric hydroarylation has been described for the first time.A variety of arylboronic acids coupled with 2-substituted 1,2-dihydroquinolines under mild reaction condition.The transformations into the enantio-enriched 2,3-diaryl-tetrahydroquinolines as well as the recovered chiral 2-aryl-dihydroquinolines were obtained with high yields and excellent enantioselectivities(86%-99% ee,s factor up to 1057).展开更多
基金supported by the National Natural Science Foundation of China(Nos.82130103,82151525 and 81903465)the Central Plains Scholars and Scientists Studio Fund(2018002)+1 种基金the Natural Science Foundation of Henan Province(No.212300410051)the Science and Technology Major Project of Henan Province(No.221100310300)。
文摘Herein,we report the dynamic kinetic resolution asymmetric acylation ofγ-hydroxy-γ-perfluoroalkyl butenolides/phthalides catalyzed by amino acid-derived bifunctional organocatalysts,and a series of ketals were obtained in high yields(up to 95%)and excellent enantioselectivities(up to 99%).In terms of synthetic utility,the reaction can be performed on a gram scale,and the product can be converted into potential biological nucleoside analog.
基金Supported by the National Natural Science Foundation of China (No. 20076019) the Natural Science Foundation of Guangdong Province (No. 000444).
文摘The enantioselective esterification of racemic 1-trimethylsilylethanol with acids catalyzed by lipase in organic solvent was successfully performed. The influence of some factors on the reaction was investigated. Among the four lipases explored, Candida rugosa lipase (CRL) showed the highest activity and enantioselectivity. Octanoic acid was the best acyl donor among the eleven acids studied and n-hexane was the most suitable medium for the reaction. The optimum shaking rate and temperature were found to be 150r·min-1 and 20℃ to 30℃, respectively. The enantiomeric excess of the remaining (5)-(-)-1-trimethylsilylethanol was 93% when substrate conversion was 53% upon incubation of the reaction mixture at 30℃, 150r·min-1 for 12 h.
文摘The chiral oxiranecarboxylic acids or esters 2a-e were obtained with lipase (CCL) in aqueous-organic system.The ee and the absolute configurations of the products were determined.
文摘Kinetic resolution is one of the most commonly used methods allowing access to enantioenriched compounds.The last two decades have seen the rapid development of kinetic resolutions enabled by N-heterocyclic carbene catalysis,and part of the achievements have been summarized in our previous review paper published in 2017.Since then,a series of new advances have been realized,and this review will provide an update of this field covering reports from mid-2017 to 2023.
基金The National Key Research and Development Program of China(Nos.2021YFA0911400 and 2021YFF0600704)the National Natural Science Foundation of China(Nos.22071033 and 21801047)are acknowledged for the financial supports。
文摘We report here a generic,green synthesis of 17 valuable syn-aryl-(2S,3R)-2–chloro-3–hydroxy esters(syn-(2S,3R)-1)in 73%-99%isolated yields along with 6.1:1–83:1 dr and 31%~>99%ee,through dynamic reductive kinetic resolution of racemic arylα–chloroβ-keto esters(2)catalyzed by an engineered ketoreductase which was obtained via ep PCR-based directed evolution.The hectogram scale synthesis of syn-(2S,3R)-1b at a substrate concentration of 120 g/L showcased the application potential of the biocatalytic method developed presently.
文摘Kinetic resolution of DL-phenylalanine methyl ester was carried out using drimobilized α -chymotrypsin (IC) as catalyst. The effects of temperatUre, pH, concentration of substrate and reactionvessels on the resolution were investigated. High quality L-phenylalanine was obtained in good yieldby an IC column.
基金financial support from the Natural Science Foundation of Ningxia(Nos.2024AAC03023 and 2024AAC03024)。
文摘The precise synthesis of planar chiral pillar[n]arenes(PAs)faces significant challenges due to their inherent dynamic racemization induced by rapid molecular flipping.To address this issue and enhance conformational stability of these macrocycles,we have developed a strategic approach involving the introduction of sterically bulky aryl(sp^(2))substituents at the molecular rims through dynamic kinetic resolution(DKR).A series of robust and chirality-aligned homo-and hetero-diaryl PAs(n=5,6)were achieved with excellent enantioselectivity(>95%ee)via Pd-catalyzed asymmetric Suzuki–Miyaura coupling reactions.Mechanism study revealed axial steric hindrance,rather than radial substitution,governs conformational chirality-locking in pillar[n]arenes.This work not only provides an attractive protocol for the enantioselective synthesis of planar chiral pillar[n]arenes,but also enriches the library of macrocycles for promising applications in chiral molecular machines,enantioselective sensors,and chiral luminescent materials.
基金the financial support from the National Natural Science Foundation of China(grant no.22171208)the Ministry of Education of Singapore(grant no.A-8001893-00-00)+2 种基金the Agency for Science,Technology and Research(grant no.A-8001271-00-00)the National University of Singapore(grant no.A-8001040-00-00)the Joint School of National University of Singapore and Tianjin University in Fuzhou.
文摘We present here a catalytic enantioconvergent aminationof alcohols for efficient access to chiral C2-and C3-substituted benzomorpholines. The racemicamino alcohol substrates of different substitutionpatterns, which are readily available from a commonprecursor, can be converted to the enantioenrichedheterocycles in a highly atom- and step-economicalfashion. In particular, an unprecedented asymmetricamination of racemic primary alcohols via dynamickinetic resolution is achieved under cooperativeiridium/iron catalysis, resulting in highly enantioenrichedC2-substituted benzomorpholines that aredifficult to access otherwise.
基金supported by the Fukuoka Naohiko Memorial Foundation.
文摘Comprehensive Summary:New chiral guanidine catalysts having axial chirality containing a methoxy group were synthesized.Subsequently,their catalytic ability was examined by applying the silylative kinetic resolution of racemic alcohols using chlorosilanes.Based on an X-ray crystallographic analysis of the catalysts,the functional role of the methoxy group was predicted,and the plausible reaction pathways and a transition state were described.It was also revealed that the existence of hydrogen bonding between the methoxy group on the catalyst and hydrogen atom at C-1 position of the substrates was of great importance for attaining high selectivity and reactivity.The proposed method is applicable to various acyclic aryl,heteroaryl,and normal-alkyl alcohols exhibiting medium to high s-values(s=15-96,15 examples).
基金supported by the National Key R&D Program of China(2022YFA1503200)the Naural Science Foundation of Jiangsu Province(BK20230078)+3 种基金the National Naural Science Foundation of China(22271146)the Fundamental Research Funds for the Central Universities(491916003301)the High Performance Computing Center(HPCC)of Nanjing Universitythe Open Research Fund of School of Chemistry and Chemical Engineering,Henan Normal University。
文摘Chirality is a common phenomenon in nature,playing a crucial role in fields such as pharmaceuticals[1],materials science[2],and life sciences[3].The catalytic synthesis of chiral molecules,particularly those bearing multiple stereogenic elements(e.g.,central,axial,planar,helical,or inherent chirality),has gained tremendous attention in organic synthesis[4].
基金supported by the NSFC(No.22471063)the Natural Science Foundation of Henan Province(242300421351,252300421719)+1 种基金Education Department of Henan Province Natural Science Research Program(23A150037)Henan Postdoctoral Science Foundation(202103087)。
文摘Planar organofluorine compounds are highly sought-after structural motifs.Herein,we present an enantioselective strategy for the synthesis of planar chiral fluoroalkenes via kinetic resolution of gem-difluorovinylferrocenes by copper-catalyzed hydrodefluorination in the presence of a base and diboron.This method was successfully applied to provide a diverse range of planar chiral gem-difluoroalkenes and Z-monofluoroalkenes with excellent regio-,stereo-and enantioselectivity.The resulting enantioenriched planar chiral fluoroalkenes could undergo various enantioretaining transformations,broadening their synthetic utility.Furthermore,density functional theory(DFT)calculations provide mechanistic insights into the origin of enantioselectivity,enhancing the understanding of this transformation.
基金the National Key Research and Development Program of China(grant no.2022YFA1503703)the National Natural Science Foundation of China(grant no.22325106)the Fundamental Research Funds for the Central Universities(grant no.2042024kf1014),and Wuhan University for financial support.
文摘Phosphorus stereocenter,a ubiquitous central chiral element,plays a crucial role in pharmaceuticals,materials science and asymmetric catalysis.As such,stereoselective construction of phosphorus stereocenters has become important in the field of organic synthesis.Herein we report a general and modular method for the construction of P-stereogenic centers via palladium/chiral norbornene cooperative catalysis-enabled desymmetrization/kinetic resolution process.It is a two-component annulation reaction that involves widely available aryl iodides and prochiral or racemic phosphinamides as the reactants.A wide variety of substrates bearing an assortment of functional groups(50 examples)are compatible with this method.Other features include a distinct enantiodiscrimination mechanism,excellent stereoselectivities,and scalability.The obtained chiral P-stereogenic products bear a common C–Br bond,which can be elaborated for the synthesis of new P-stereogenic compounds with diverse structural features.In addition,preliminary studies uncover the promising chiroptical properties of these P-stereogenic cyclic phosphinamides.Density functional theory calculations are performed to reveal that the noncovalent hydrogen bonding interaction is the origin of enantiodiscrimination during the desymmetrization process.
基金the Natural Science Foundation of Guangdong Province(Nos.2024A1515011116 and 2023A1515012820)Guangzhou Science and Technology Program(No.202201020559)+3 种基金the Pearl River Talent Program of Guangdong Province(Youth Top-Notch Talent,2021QN020472 and 2021QN02x046)Fundamental Research Funds for the Central Universities(21623417)the National Natural Science Foundation of China(Grant No.21602203)the Natural Science Foundation of Zhejiang Province(Grant Nos.LY20B020o02,LY20B020010)for financialsupport.
文摘Bridged biaryl atropisomers are widely recognized as a significant structural motif commonly found in bioactive molecules and natural products.Herein,we report an organocatalytic dynamic kinetic resolution(DKR)approach for the synthesis of optically pure biaryl-bridged seven-membered lactones.In the presence of a chiral N-heterocyclic carbene(NHC)catalyst,racemic biaryl-bridged hemiacetals,generated in situ from 2’-formyl-2-biphenyl carboxylic acids,undergo stereoselective coupling with NHC-bound acylazolium intermediates derived from NHC and aldehydes.This transformation delivers seven-membered biaryl-bridged lactone products with very high yields and good to excellent regio-and enantioselectivities.
基金supported by the National Natural Science Foundation of China(22072035,22361162606,22371060)the Zhejiang Provincial Natural Science Foundation of China(LZ23B020002,LY22B020006,LR22B020002)+1 种基金the Special Support Program for High-level Talents of Zhejiang Province(2021R51005)the Hangzhou Science and Technology Bureau(TD2020015)。
文摘Recent developments in chirality chemistry have revealed remarkable instances of atropisomers featuring multiple chiral elements.Despite significant progress in the synthesis and application of atropisomers,developing a synthetic protocol for the simultaneous introduction of axial and point chirality is still a fascinating challenge.In this context,we present a convenient and versatile method for synthesizing novel atropisomers with axial and point chirality.This approach,based on a new reaction mechanism with nickel-controlled Si–C bond activation,facilitates the controllable migratory insertion of aldehydes into the Ni–C bond.We utilize multidimensional strategies of desymmetrization,kinetic resolution and dynamic kinetic resolution to complete enantioselective nickel-catalyzed ring expansion of benzosilacyclobutenes with aldehydes.The design of multidimensional kinetic resolution,desymmetrization,and dynamic resolution,features a straightforward catalytic system,mild reaction conditions,and broad functional group tolerances.Various axially chiral biaryl oxasilacycles bearing carbon-or siliconstereogenic centers are obtained with excellent diastereo-and enantio-selectivities(up to>20:1 dr and>99.9%ee)through the use of a chiral Ni complex with a large cavity-type 1,1,4,4-tetra-aryl-2,3-O-isopropylidene-L-threitol(TADDOL)-derived phosphoramidite ligand.
基金supported by the National Key Research and Development Program of China(2023YFA1507500)the National Natural Science Foundation of China(22171260,92356302)+1 种基金the Natural Science Foundation of Liaoning Province(2023-MS-009)the Dalian Institute of Chemical Physics(DICP I202442)。
文摘Asymmetric direct hydrogenation(ADH)is a straightforward and atom-economic methodology to achieve optically active compounds.The synthesis of chiral compounds bearing stereogenic centers has been well established.In contrast,the construction of atropisomers,especially atropisomers bearing multiple chiral elements,has sporadically been explored.Herein,we report an innovative atroposelective iridium-catalyzed hydrogenation of N-arylindole ketones and heterobiaryl ketones via dynamic kinetic resolution(DKR)based on a Lewis acid-base interaction between the nitrogen atom and the carbonyl group of ketones,providing C-N and C-C atropisomers bearing multiple chiral elements with excellent enantioselectivities,diastereoselectivities and yields.The lynchpin of the DKR-ADH process stands in the newly developed planar-chiral tridentate PNO ligand,which ensures the excellent control of enantioselectivity and diastereoselectivity simultaneously.The synthetic utilization of this protocol is proved through stereospecific transformation to a tridentate PNN ligand bearing axial and central chirality,which shows promising potential in iridium-catalyzed asymmetric hydrogenation of simple ketones.
基金supported by the National Natural Science Foundation of China(21901249)Taishan Scholars Program of Shandong Province(tsqn201812112)+1 种基金the Major Science and Technology Innovation Program of Shandong Province(2022CXGC020604)the Natural Science Foundation of Shandong Province(ZR2023ME008)。
文摘Asymmetric kinetic resolution polymerization(AKRP)provides an ideal way to obtain highly isotactic polymers and optically pure monomers.However,highly enantioselective AKRP process is still rarely reported to date.And the AKRP of racemic lactide(rac-LA)remains a challenge.Here,in this paper,the AKRP of rac-LA was achieved by means of an enhanced enantiomorphic site control,delivering isotactic polylactide(PLA)and enantiomeric enriched lactide(LA)with the highest kinetic resolution coefficients(k_(rel))to date.Different from common(Salen)Al complex,a series of new chiral(BisSalen)Al complexes were designed and synthesized to form a more confined chiral microenvironment and further improve specific discrimination of rac-LA.The NMR analysis,kinetic studies,the activation parameters and thermal properties of the resulting PLAs provided strong evidence for enhanced enantiomorphic site control.This work enables highly enantioselective AKRP of rac-LA.
基金supported by the National Natural Science Foundation of China (21961006,32172459,22371057)Science and Technology Department of Guizhou Province (Qiankehejichu-ZK[2021]Key033)+1 种基金Program of Introducing Talents of Discipline to Universities of China (111 Program,D20023) at Guizhou UniversityFrontiers Science Center for Asymmetric Synthesis and Medicinal Molecules,Department of Education,Guizhou Province (Qianjiaohe KY (2020)004),Guizhou University (China)。
文摘N-heterocyclic carbene-catalyzed enantioselective kinetic resolutions,dynamic kinetic resolutions,and desymmetrization reactions are systematically reviewed.The content is organized according to the activation modes involved in these transformations.Future advances within this highly active research field are discussed from our perspectives on the topic.
基金NSFC(Grant No.22171186)ShanghaiTech University start-up funding for financial supportthe support from Analytical Instrumentation Center(contract no.SPST-AIC10112914),SPST,ShanghaiTech University,and Dr.Na Yu for the X-ray crystallographic analysis.
文摘An efficient method for asymmetric synthesis of acyclic α-tertiary amine derivatives has been achieved through enantioselective aminations of α-branched ynones with azodicarboxylates enabled by chiral phosphoric acid catalysis.Moreover,kinetic resolution of racemic starting material was realized under these conditions,which gave access to valuable enantioenriched α-substituted ketones.
基金NSFC(Grant No.22171186) and ShanghaiTech University start-up funding for financial supportthe support from Analytical Instrumentation Center(contract no.SPST-AIC10112914),SPST。
文摘An efficient kinetic resolution(KR)protocol for 1,2-diamines has been developed through asymmetric electrophilic aminations of anilines enabled by chiral phosphoric acid catalysis.A wide array of substituted 1,2-diamines were compatible with this method,generating both the recovered staring materials and the amination products with high enantioselectivities(with s-factor up to 218).Notably,this method is amenable to the kinetic resolution of 1,2-diamines bearingα-tertiary amine moieties,which represents the first KR of this type of 1,2-diamines.Facile removal of the introduced hydrazine group and oxidative cleavage of the N-aryl group to release the free primary amine demonstrate the value of this method.
基金the Shenzhen Overseas High-level Talents Innovation Plan of Technical Innovation Project(No.KQJSCX20180319114439973)for financial support.
文摘A highly efficient kinetic resolution of racemic 2-substituted 1,2-dihydroquinolines via Rh-catalyzed asymmetric hydroarylation has been described for the first time.A variety of arylboronic acids coupled with 2-substituted 1,2-dihydroquinolines under mild reaction condition.The transformations into the enantio-enriched 2,3-diaryl-tetrahydroquinolines as well as the recovered chiral 2-aryl-dihydroquinolines were obtained with high yields and excellent enantioselectivities(86%-99% ee,s factor up to 1057).
