The C—F bond transformation of gem-difluorinated cyclopropanes without cleavage of the highly strained C—C bond is an intractable challenge. The synthesis of cyclopropanone ketals via double defluorination of gem-di...The C—F bond transformation of gem-difluorinated cyclopropanes without cleavage of the highly strained C—C bond is an intractable challenge. The synthesis of cyclopropanone ketals via double defluorination of gem-difluorinated cyclo-propanesunder transition-metal free and basic conditions has been developed. A broad range of gem-difluorinated cyclopro-panesand alcohols are amenable in present reaction to permit the synthesis of corresponding products in high yields. The reaction is elucidated to proceed via elimination and addition other than direct substitution based on the mechanistic studies. This transformation not only provides a new strategy for the construction of cyclopropanone ketals, but also reveals a new paradigm on C—F bond transformation without ring-opening of gem-difluorinated cyclopropanes.展开更多
The packed density, detonation velocities, and detonation pressures of a series of cyclopropane derivatives were investigated to look for high energy density compounds. For exploring the possibility of synthesis, the ...The packed density, detonation velocities, and detonation pressures of a series of cyclopropane derivatives were investigated to look for high energy density compounds. For exploring the possibility of synthesis, the bond order, heats of formation(HOF), bond dissociation energy(BDE), and characteristic height were calculated. Based on our results, A3 has the best detonation characters. Both A1 and A2 showed comparative detonation parameters and compact sensitivity with RDX, and could be regarded as the candidates of high energy density molecules.Both the heats of formation and explosive heats rose with the increase of nitrimino groups and the strain energy of three-membered ring. For A1 compound, pyrolysis mechanism might be a mix one(breakages of C–C and N–NO2 bonds). However, for A2 and A3 compounds, the N–NO2 is the trigger bond in explosive reactions. Our results may provide the basic information for further study of this kind of compounds.展开更多
A facile and convenient one-pot synthesis method of substituted cyclopropanes in water has been developed. A series of 1,1-disubstituted cyclopropanes 3 were synthesized from the reaction of β-dicarbonyl compounds 1 ...A facile and convenient one-pot synthesis method of substituted cyclopropanes in water has been developed. A series of 1,1-disubstituted cyclopropanes 3 were synthesized from the reaction of β-dicarbonyl compounds 1 with 1,2-dibromoethane 2, in very high yields catalyzed by tetrabutylammonium bromide（TBAB） at 50 ℃ in the presence of K2CO3 in water. The catalyst TBAB in the aqueous phase can be reused after the separation of organic products.展开更多
Synthesis and ring-opening reaction of TADDOL analogue with cyclopropane as chiral backbone were described. A plausible ring-opening and carbonium ion rearrangement mechanism have been proposed.
Trans-1,2-bis(2 ' -(5 ' -phenyl-1 ' , 3 ' , 4 '-oxadiazolyl ) ) cyclopropane (BDCP) and its eleven substituted novel derivatives were synthesized. Besides four derivatives of l,2-bis(2'-(5'...Trans-1,2-bis(2 ' -(5 ' -phenyl-1 ' , 3 ' , 4 '-oxadiazolyl ) ) cyclopropane (BDCP) and its eleven substituted novel derivatives were synthesized. Besides four derivatives of l,2-bis(2'-(5'-phenyl-l ' , 3 ' , 4 ' -ox-adiazo1yl))ethane (BPDS) were also synthesized as model compounds. The crystal structure of ethyl BDCP was determined and the cyclopropane ring was found to be able to transmit conjugation between the aromatic groups directly bonding with it by studying the ultraviolet and fluorescent spectra of the above compounds.展开更多
We describe a versatile electrophile addition/SPR sequence of readily available cyclopropyl carbinols that affords multi-substituted carbonylated cyclopropanes with high stereo-fidelity.This approach tolerates various...We describe a versatile electrophile addition/SPR sequence of readily available cyclopropyl carbinols that affords multi-substituted carbonylated cyclopropanes with high stereo-fidelity.This approach tolerates various heteroatom electrophiles,migration of carbon moiety of all possible hybridization states,facile ring reorganization and natural compound valorization.The examples represent an unprecedented version of SPR wherein migration to a non-benzylic bulky tertiary carbo-cation is realized with promising enantiocontrol.展开更多
In the presence of CrC13 /Fe bimetal couple,per(poly)fluoroalkyl iodides add to vinyl cyclopropane compounds giving addition-ring-opening products in good yields.
Polysubstituted cyclopropanes were efficiently prepared with poly（ethylene glycol）（PEG） as soluble support. The reaction of PEG-supported pyridinium ylide with arylidenemalononitrile（R=CN） or ethyl arylidenecyan...Polysubstituted cyclopropanes were efficiently prepared with poly（ethylene glycol）（PEG） as soluble support. The reaction of PEG-supported pyridinium ylide with arylidenemalononitrile（R=CN） or ethyl arylidenecyanoa-cetate（R=COOEt） in the presence of triethylamine（TEA） afforded PEG-supported cyclopropanecarboxylates, which were cleaved by 1% KCN/EtOH to obtain polysubstituted cyclopropanes with exclusive trans-selectivity and good yields.展开更多
Two new optically active trans-2-atrfinocyclopropanecarboxylic esters （β-ACCs） of optical purity 91%-96% were concisely synthesized via ozonization, oxidation, Curtius rearrangement from commercial available optica...Two new optically active trans-2-atrfinocyclopropanecarboxylic esters （β-ACCs） of optical purity 91%-96% were concisely synthesized via ozonization, oxidation, Curtius rearrangement from commercial available optically active trans-chrysanthemate in total yield 36%.展开更多
Eight pairs of enantiomers of cyclopropane derivatives were resolved on capillary gas chromatographic columns using three new 2, 6-di-O-allyl-3-O-acylated-β-cyclodextrins as chiral stationary phases. It was found th...Eight pairs of enantiomers of cyclopropane derivatives were resolved on capillary gas chromatographic columns using three new 2, 6-di-O-allyl-3-O-acylated-β-cyclodextrins as chiral stationary phases. It was found that the three β-CDs can separate some of the racemic cyclopropane derivatives well.展开更多
Various addition-elimination approaches have been explored for diastereoselective construction of 1-amino- 1-cyclopropane-carboxylic acid (ACPC) derivatives, and the desired product was obtained from a reaction of cyc...Various addition-elimination approaches have been explored for diastereoselective construction of 1-amino- 1-cyclopropane-carboxylic acid (ACPC) derivatives, and the desired product was obtained from a reaction of cyclo(NAc-L-Val-NAc-Gly) and methyl α-bro-moacrylate under protonic solvent.展开更多
A new procedure for the highly diastereoselective synthesis of （1S）-trans-cyclopropane derivatives using a fructose derivative as the chiral auxiliary was developed. Chloroacetylated 1,2;4,5-di-O-isopropylidene-D-fr...A new procedure for the highly diastereoselective synthesis of （1S）-trans-cyclopropane derivatives using a fructose derivative as the chiral auxiliary was developed. Chloroacetylated 1,2;4,5-di-O-isopropylidene-D-fructopyranose was reacted with a tertiary amine to form the ammonium salt, which was treated with cesium carbonate to give the cyclopropane derivative through ylide intermediate. The described procedure provides an efficient method to synthesize optically pure dior poly-substituded cyclopropanes.展开更多
We described a Yb(OTf)_(3) combined with Pybox ligand catalyzed asymmetric[3+3]cycloaddition of N-vinyl cinnamaldehyde nitrones with activated cyclopropanes to prepare various functionalized 1,2-oxazines in 24%—95% y...We described a Yb(OTf)_(3) combined with Pybox ligand catalyzed asymmetric[3+3]cycloaddition of N-vinyl cinnamaldehyde nitrones with activated cyclopropanes to prepare various functionalized 1,2-oxazines in 24%—95% yields and 22%—96%ee.Experimental results revealed that the reaction underwent a domino[3+3]cycloaddition,dealkenylation,and aza-1,4-addition in three steps.The chiral 1,2-oxazine could be obtained in gram scales and easily converted into various 1,2-oxazine scaffolds.The present method features broad substrate scope,good functional group compatibility,three-component domino reaction,and asymmetric[3+3]cycloaddition of N-vinyl nitrones with activated cyclopropanes.展开更多
Chlorine-substituted ketones are crucial intermediates in organic synthesis,and acyl chlorination of chemical feedstocks employing commercially available benzoyl chloride provides an atom-and-step economic route for t...Chlorine-substituted ketones are crucial intermediates in organic synthesis,and acyl chlorination of chemical feedstocks employing commercially available benzoyl chloride provides an atom-and-step economic route for their synthesis.While atomtransfer radical addition(ATRA)has proven effective for 1,2-acyl chlorination,the efficient realization of 1,3-acyl chlorination has remained a considerable challenge.In this study,an NHC/photocatalyst dual-catalyzed system was developed to facilitate the 1,3-acyl chlorination of cyclopropanes using benzoyl chloride as a bifunctional reagent.This strategy also enables the synthesis of acyl-cyclopropanes with quaternary carbon centers through a nucleophilic annulation process.The practical utility of this approach was demonstrated through large-scale synthesis,product derivatization,and the preparation of analogs of antipsychotics,including haloperidol,melperone and fluanisone.展开更多
Methylenecyclopropanes are among the most robust building blocks in synthetic chemistry,but the study on(difluoromethylene)-cyclopropanes is rather limited,because of the difficulty in the synthesis of these compounds...Methylenecyclopropanes are among the most robust building blocks in synthetic chemistry,but the study on(difluoromethylene)-cyclopropanes is rather limited,because of the difficulty in the synthesis of these compounds.Herein,we report the invention of a novel carbene precursor,(1-diazo-2,2,2-trifluoroethyl)dimethyl(phenyl)silane(1a)and its application in the synthesis of(difluoromethylene)cyclopropanes.The reaction proceeds through photocatalyzed[2+1]cyclization of readily available alkenes and diazo compound 1a followed by the work-up of the reaction through the elimination of silyl fluoride.Both aromatic and aliphatic alkenes are tolerated by the mild reaction conditions,affording various(difluoromethylene)cyclopropanes in 44%–82%yield(>30 examples).Gram scale reaction and diversified downstream transformations highlight the synthetic potential of this methodology.The experimental and DFT calculations suggest the involvement of triplet carbene intermediate.展开更多
Radical-involved allylation reactions have emerged as a powerful platform for construction of carbon-carbon and carbonheteroatom bonds, facilitating the strategic incorporation of diverse allyl moieties. Nevertheless,...Radical-involved allylation reactions have emerged as a powerful platform for construction of carbon-carbon and carbonheteroatom bonds, facilitating the strategic incorporation of diverse allyl moieties. Nevertheless, this burgeoning field still faces ongoing challenges, including limitations of radical precursors and coupling partners, and difficulties in achieving enantiocontrol. Herein, we report for the first time a highly enantioselective radical allylation involving β-keto esters with vinyl cyclopropanes utilizing a synergistic dual photoredox/nickel catalysis under visible light irradiation. The mild and redox-neutral catalytic protocol demonstrates an extensive substrate compatibility and good functional tolerance, providing access to enantioenriched β-keto esters featuring quaternary α-stereocenter with good yields and high enantioselectivities. Preliminary mechanistic studies have uncovered that the success of the reaction hinges on the dual roles of nickel catalyst, including in situ formation of photoredox sensitive substrate/Ni complex and the ensuing asymmetric radical addition step.展开更多
Comprehensive Summary,Herein,we report nickel-catalyzed cross-coupling of gem-difluorinated cyclopropanes with boronic acids,providing the corresponding arylated 2-fluoroallylic scaffolds.This approach used commercial...Comprehensive Summary,Herein,we report nickel-catalyzed cross-coupling of gem-difluorinated cyclopropanes with boronic acids,providing the corresponding arylated 2-fluoroallylic scaffolds.This approach used commercially available phosphine ligand Xantphos to obtain monofluorinated alkenes with high regioselectivity and Z-stereoselectivity.Mechanistic studies proposed a Ni(II)-fluoroallyl pathway and excluded the radical pathway.展开更多
Comprehensive Summary A general and efficient strategy for the synthesis ofγ-lactams has been reported.The hydroxylamines form Lossen rearrangement products of electron-deficient group migration with base and then un...Comprehensive Summary A general and efficient strategy for the synthesis ofγ-lactams has been reported.The hydroxylamines form Lossen rearrangement products of electron-deficient group migration with base and then undergo[3+2]cycloaddition reaction with vinyl cyclopropane,which could be performed with broad substrate scope,excellent functional group tolerance and high efficiency to produce the desired products.It also allowed further modification to other derivatives of theseγ-lactams.展开更多
A new type of trisoxazoline and bisthiazoline based ligands have been developed,which are absent of chiral motif on the parent skeleton and containa chiral backbone on sidearm.The ligands promote the amine nucleophili...A new type of trisoxazoline and bisthiazoline based ligands have been developed,which are absent of chiral motif on the parent skeleton and containa chiral backbone on sidearm.The ligands promote the amine nucleophilic ring opening reaction of 1,1-cyclopropane diesters smoothly,furnishing the γ-amino acid derivatives in high yield with moderate to good enantioselectivity.展开更多
Under the catalysis of Lewis acid Co（CIO4）2 the reaction of the sterically hindered 1,1,2,3-tetrasubstituted cyclopropanes with arylamines in refluxing THF gave the functionalized 2-aminopyrroles with sequential rin...Under the catalysis of Lewis acid Co（CIO4）2 the reaction of the sterically hindered 1,1,2,3-tetrasubstituted cyclopropanes with arylamines in refluxing THF gave the functionalized 2-aminopyrroles with sequential ring-opening of cyclopropane, nucleophilic substitution, nucleophilic addition of cyano group and recyclization processes.展开更多
文摘The C—F bond transformation of gem-difluorinated cyclopropanes without cleavage of the highly strained C—C bond is an intractable challenge. The synthesis of cyclopropanone ketals via double defluorination of gem-difluorinated cyclo-propanesunder transition-metal free and basic conditions has been developed. A broad range of gem-difluorinated cyclopro-panesand alcohols are amenable in present reaction to permit the synthesis of corresponding products in high yields. The reaction is elucidated to proceed via elimination and addition other than direct substitution based on the mechanistic studies. This transformation not only provides a new strategy for the construction of cyclopropanone ketals, but also reveals a new paradigm on C—F bond transformation without ring-opening of gem-difluorinated cyclopropanes.
基金supported by the National Natural Science Foundation of China(51374121)
文摘The packed density, detonation velocities, and detonation pressures of a series of cyclopropane derivatives were investigated to look for high energy density compounds. For exploring the possibility of synthesis, the bond order, heats of formation(HOF), bond dissociation energy(BDE), and characteristic height were calculated. Based on our results, A3 has the best detonation characters. Both A1 and A2 showed comparative detonation parameters and compact sensitivity with RDX, and could be regarded as the candidates of high energy density molecules.Both the heats of formation and explosive heats rose with the increase of nitrimino groups and the strain energy of three-membered ring. For A1 compound, pyrolysis mechanism might be a mix one(breakages of C–C and N–NO2 bonds). However, for A2 and A3 compounds, the N–NO2 is the trigger bond in explosive reactions. Our results may provide the basic information for further study of this kind of compounds.
基金Supported by the National Natural Science Foundation of China(Nos.20572013, 20711130229)the Ministry of Educa-tion of China(No.105061).
文摘A facile and convenient one-pot synthesis method of substituted cyclopropanes in water has been developed. A series of 1,1-disubstituted cyclopropanes 3 were synthesized from the reaction of β-dicarbonyl compounds 1 with 1,2-dibromoethane 2, in very high yields catalyzed by tetrabutylammonium bromide（TBAB） at 50 ℃ in the presence of K2CO3 in water. The catalyst TBAB in the aqueous phase can be reused after the separation of organic products.
基金founded by the National Natural Science Foundation of China(No.20472111).
文摘Synthesis and ring-opening reaction of TADDOL analogue with cyclopropane as chiral backbone were described. A plausible ring-opening and carbonium ion rearrangement mechanism have been proposed.
文摘Trans-1,2-bis(2 ' -(5 ' -phenyl-1 ' , 3 ' , 4 '-oxadiazolyl ) ) cyclopropane (BDCP) and its eleven substituted novel derivatives were synthesized. Besides four derivatives of l,2-bis(2'-(5'-phenyl-l ' , 3 ' , 4 ' -ox-adiazo1yl))ethane (BPDS) were also synthesized as model compounds. The crystal structure of ethyl BDCP was determined and the cyclopropane ring was found to be able to transmit conjugation between the aromatic groups directly bonding with it by studying the ultraviolet and fluorescent spectra of the above compounds.
基金Financial support of this work from National Natural Science Foundation of China(No.21871045)startup funding from Changchun University of Technology。
文摘We describe a versatile electrophile addition/SPR sequence of readily available cyclopropyl carbinols that affords multi-substituted carbonylated cyclopropanes with high stereo-fidelity.This approach tolerates various heteroatom electrophiles,migration of carbon moiety of all possible hybridization states,facile ring reorganization and natural compound valorization.The examples represent an unprecedented version of SPR wherein migration to a non-benzylic bulky tertiary carbo-cation is realized with promising enantiocontrol.
文摘In the presence of CrC13 /Fe bimetal couple,per(poly)fluoroalkyl iodides add to vinyl cyclopropane compounds giving addition-ring-opening products in good yields.
基金Supported by the National High Technology Research and Development Program of China(No.2009AA03Z420)the Natural Science Foundation of Hubei Province of China(Nos.2007ABA031,2008CDA078)
文摘Polysubstituted cyclopropanes were efficiently prepared with poly（ethylene glycol）（PEG） as soluble support. The reaction of PEG-supported pyridinium ylide with arylidenemalononitrile（R=CN） or ethyl arylidenecyanoa-cetate（R=COOEt） in the presence of triethylamine（TEA） afforded PEG-supported cyclopropanecarboxylates, which were cleaved by 1% KCN/EtOH to obtain polysubstituted cyclopropanes with exclusive trans-selectivity and good yields.
基金Finacial support by the National Natural Science Foundation of China(No.2047211)is gratefully acknowledged.
文摘Two new optically active trans-2-atrfinocyclopropanecarboxylic esters （β-ACCs） of optical purity 91%-96% were concisely synthesized via ozonization, oxidation, Curtius rearrangement from commercial available optically active trans-chrysanthemate in total yield 36%.
文摘Eight pairs of enantiomers of cyclopropane derivatives were resolved on capillary gas chromatographic columns using three new 2, 6-di-O-allyl-3-O-acylated-β-cyclodextrins as chiral stationary phases. It was found that the three β-CDs can separate some of the racemic cyclopropane derivatives well.
文摘Various addition-elimination approaches have been explored for diastereoselective construction of 1-amino- 1-cyclopropane-carboxylic acid (ACPC) derivatives, and the desired product was obtained from a reaction of cyclo(NAc-L-Val-NAc-Gly) and methyl α-bro-moacrylate under protonic solvent.
基金National Natural Science Foundation of China (Grant No. 20602001)
文摘A new procedure for the highly diastereoselective synthesis of （1S）-trans-cyclopropane derivatives using a fructose derivative as the chiral auxiliary was developed. Chloroacetylated 1,2;4,5-di-O-isopropylidene-D-fructopyranose was reacted with a tertiary amine to form the ammonium salt, which was treated with cesium carbonate to give the cyclopropane derivative through ylide intermediate. The described procedure provides an efficient method to synthesize optically pure dior poly-substituded cyclopropanes.
基金Financial support from the NSFC(22071035)Natural Science Foundation of Guangxi(2023GXNSFDA026025)+3 种基金Guangxi Science and Technology Plan Project(AD23026046)Graduate Innovation Training Program of Guangxi(YCSW2024160)Natural Science Foundation of Sichuan(2023NSFSC1087)Guangxi Bagui Young Scholar is greatly appreciated.
文摘We described a Yb(OTf)_(3) combined with Pybox ligand catalyzed asymmetric[3+3]cycloaddition of N-vinyl cinnamaldehyde nitrones with activated cyclopropanes to prepare various functionalized 1,2-oxazines in 24%—95% yields and 22%—96%ee.Experimental results revealed that the reaction underwent a domino[3+3]cycloaddition,dealkenylation,and aza-1,4-addition in three steps.The chiral 1,2-oxazine could be obtained in gram scales and easily converted into various 1,2-oxazine scaffolds.The present method features broad substrate scope,good functional group compatibility,three-component domino reaction,and asymmetric[3+3]cycloaddition of N-vinyl nitrones with activated cyclopropanes.
基金supported by the National Key R&D Program of China(2024YFA1509704)the National Natural Science Foundation of China(22471034,22193012,22201033)+1 种基金the Natural Science Foundation of Jilin Province(20230101047JC,YDZJ202201ZYTS338)the Fundamental Research Funds for the Central Universities。
文摘Chlorine-substituted ketones are crucial intermediates in organic synthesis,and acyl chlorination of chemical feedstocks employing commercially available benzoyl chloride provides an atom-and-step economic route for their synthesis.While atomtransfer radical addition(ATRA)has proven effective for 1,2-acyl chlorination,the efficient realization of 1,3-acyl chlorination has remained a considerable challenge.In this study,an NHC/photocatalyst dual-catalyzed system was developed to facilitate the 1,3-acyl chlorination of cyclopropanes using benzoyl chloride as a bifunctional reagent.This strategy also enables the synthesis of acyl-cyclopropanes with quaternary carbon centers through a nucleophilic annulation process.The practical utility of this approach was demonstrated through large-scale synthesis,product derivatization,and the preparation of analogs of antipsychotics,including haloperidol,melperone and fluanisone.
基金supported by the National Key Research and Development Program of China(2022YFA1506100)Shenzhen Science and Technology Program(JCYJ20220818100604009)Guangdong Basic and Applied Basic Research Foundation(2021A1515010105,2023A1515010601)。
文摘Methylenecyclopropanes are among the most robust building blocks in synthetic chemistry,but the study on(difluoromethylene)-cyclopropanes is rather limited,because of the difficulty in the synthesis of these compounds.Herein,we report the invention of a novel carbene precursor,(1-diazo-2,2,2-trifluoroethyl)dimethyl(phenyl)silane(1a)and its application in the synthesis of(difluoromethylene)cyclopropanes.The reaction proceeds through photocatalyzed[2+1]cyclization of readily available alkenes and diazo compound 1a followed by the work-up of the reaction through the elimination of silyl fluoride.Both aromatic and aliphatic alkenes are tolerated by the mild reaction conditions,affording various(difluoromethylene)cyclopropanes in 44%–82%yield(>30 examples).Gram scale reaction and diversified downstream transformations highlight the synthetic potential of this methodology.The experimental and DFT calculations suggest the involvement of triplet carbene intermediate.
基金the National Natural Science Foundation of China (22171099, and 92256301)the National Key R&D Program of China (2023YFA1507203 and 2022YFA1506100)+3 种基金the Open Research Fund of School of Chemistry and Chemical Engineeringthe Fundamental Research Funds for the Central Universities of China (CCNU24JCPT016)Henan Normal University (2021YB02)the Double-Thousand Talents Plan of Jiangxi Province (jxsq2023102004)。
文摘Radical-involved allylation reactions have emerged as a powerful platform for construction of carbon-carbon and carbonheteroatom bonds, facilitating the strategic incorporation of diverse allyl moieties. Nevertheless, this burgeoning field still faces ongoing challenges, including limitations of radical precursors and coupling partners, and difficulties in achieving enantiocontrol. Herein, we report for the first time a highly enantioselective radical allylation involving β-keto esters with vinyl cyclopropanes utilizing a synergistic dual photoredox/nickel catalysis under visible light irradiation. The mild and redox-neutral catalytic protocol demonstrates an extensive substrate compatibility and good functional tolerance, providing access to enantioenriched β-keto esters featuring quaternary α-stereocenter with good yields and high enantioselectivities. Preliminary mechanistic studies have uncovered that the success of the reaction hinges on the dual roles of nickel catalyst, including in situ formation of photoredox sensitive substrate/Ni complex and the ensuing asymmetric radical addition step.
基金the funding support of the National Key R&D Program of China(2021YFF0701600)NSFC(21901043,21921003,and 22031004)STCSM(21ZR1445900)and Shanghai Municipal Education Commission(20212308).
文摘Comprehensive Summary,Herein,we report nickel-catalyzed cross-coupling of gem-difluorinated cyclopropanes with boronic acids,providing the corresponding arylated 2-fluoroallylic scaffolds.This approach used commercially available phosphine ligand Xantphos to obtain monofluorinated alkenes with high regioselectivity and Z-stereoselectivity.Mechanistic studies proposed a Ni(II)-fluoroallyl pathway and excluded the radical pathway.
基金the National Natural Science Foundation of China(21925108,21901203,21901204)for financial support.
文摘Comprehensive Summary A general and efficient strategy for the synthesis ofγ-lactams has been reported.The hydroxylamines form Lossen rearrangement products of electron-deficient group migration with base and then undergo[3+2]cycloaddition reaction with vinyl cyclopropane,which could be performed with broad substrate scope,excellent functional group tolerance and high efficiency to produce the desired products.It also allowed further modification to other derivatives of theseγ-lactams.
基金We are grateful for the financial support from the Natural Science Foundation of China(Nos.21121062,and 21272250),and Chinese Academy of Sciences.
文摘A new type of trisoxazoline and bisthiazoline based ligands have been developed,which are absent of chiral motif on the parent skeleton and containa chiral backbone on sidearm.The ligands promote the amine nucleophilic ring opening reaction of 1,1-cyclopropane diesters smoothly,furnishing the γ-amino acid derivatives in high yield with moderate to good enantioselectivity.
文摘Under the catalysis of Lewis acid Co（CIO4）2 the reaction of the sterically hindered 1,1,2,3-tetrasubstituted cyclopropanes with arylamines in refluxing THF gave the functionalized 2-aminopyrroles with sequential ring-opening of cyclopropane, nucleophilic substitution, nucleophilic addition of cyano group and recyclization processes.
