Chemical glycosylation methodologies for the preparation of the bioactive oligosaccharides and glycoconjugates promise reliable access to these compounds as homogeneous materials with welldefined structures in suffici...Chemical glycosylation methodologies for the preparation of the bioactive oligosaccharides and glycoconjugates promise reliable access to these compounds as homogeneous materials with welldefined structures in sufficient amounts.Here we report a novel activation method of thio(seleno)glycosides employing donor-acceptor cyclopropane(DAC)agents and Sc(OTf)_(3).The Lewis acid catalyst converts DAC into a formal 1,3-zwitterionic species that in turn activates thioglycosides to furnish a glycosyl 1,4-zwitterionic intermediate,interconverting with reactive glycosyl oxocarbenium in the solution with reversible leaving-group dissociation.This activation method effectively promotes glycosylation reactions between both armed and disarmed thioglycosides and structurally diverse acceptors,affording oligosaccharides with satisfactory yields.The usefulness of our activation method has been demonstrated by the mechanism-inspired 2,4-dinitrobenzenesulfonyl(DNs)group directed S_(N)2-like glycosylation and the facile preparation of both linear and branched trisaccharides in one pot via controlled sequential activation of thioglycoside donors.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
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
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
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
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
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
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
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.
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
Light is a fundamental environmental factor for living organisms on earth—not only as a primary energy source but also as an informational signal.In fungi,light can be used as an indicator for both time and space to ...Light is a fundamental environmental factor for living organisms on earth—not only as a primary energy source but also as an informational signal.In fungi,light can be used as an indicator for both time and space to control important physiological and morphological responses.Botrytis cinerea(B.cinerea)is a devastating phytopathogenic fungus that exploits light cues to optimize virulence and the balance between conidiation and sclerotia development,thereby improving its dispersal and survival in ecosystems.However,the components and mechanisms underlying these processes remain obscure.Here,we identify a novel light-signaling component in B.cinerea,BcCfaS,which encodes a putative cyclopropane fatty-acyl-phospholipid synthase.BcCfaS is strongly induced by light at the transcriptional level and plays a crucial role in regulating photomorphogenesis.Deletion of BcCfaS results in reduced vegetative growth,altered colony morphology,impaired sclerotial development,and enhanced conidiation in a lightdependent manner.Moreover,the mutant exhibits serious defects in stress response and virulence on the host.Based on a lipidomics analysis,a number of previously unknown fungal lipids and many BcCfaS-regulated lipids are identified in B.cinerea,including several novel phospholipids and fatty acids.Importantly,we find that BcCfaS controls conidiation and sclerotial development by positively regulating methyl jasmonate(MeJA)synthesis to activate the transcription of light-signaling components,revealing for the first time the metabolic base of photomorphogenesis in fungi.Thus,we propose that BcCfaS serves as an integration node for light and lipid metabolism,thereby providing a regulatory mechanism by which fungi adapt their development to a changing light environment.These new findings provide an important target for antifungal design to prevent and control fungal disease.展开更多
Inspired by the anti-pancreatic promising results of our novel aminated cyclopropylmethylphosphonate compounds, an in vitro anti-prostate cancer activity exploration of these compounds was carried out on human prostat...Inspired by the anti-pancreatic promising results of our novel aminated cyclopropylmethylphosphonate compounds, an in vitro anti-prostate cancer activity exploration of these compounds was carried out on human prostate cancer cell line PC-3, and showed potent inhibiting activity at low micromolar concentrations (with an IC50 of approximately 45 μM).展开更多
The reactions of halocarbenes with pre-aromatic ketones 1, 2 resulted in cyclopropanation and deoxygenation products. The varying product ratio could be accounted for by a mechanism involving the carbonyl ylide interm...The reactions of halocarbenes with pre-aromatic ketones 1, 2 resulted in cyclopropanation and deoxygenation products. The varying product ratio could be accounted for by a mechanism involving the carbonyl ylide intermediate.展开更多
基金the National Natural Science Foundation of China(grant no.22207092)the Natural Science Basic Research Plan of Shaanxi Province of China(grant no.2022JQ-091)+3 种基金the Fundamental Research Funds for the Central Universities(grant no.G2021KY05117)from Chinathe National Research Foundation(grant no.NRF-CRP22-2019-0002)the Ministry of Education(grant no.MOE-T2EP30120-0007)A*STAR(grant no.A20E5c0087)from Singapore for their financial support of this research.
文摘Chemical glycosylation methodologies for the preparation of the bioactive oligosaccharides and glycoconjugates promise reliable access to these compounds as homogeneous materials with welldefined structures in sufficient amounts.Here we report a novel activation method of thio(seleno)glycosides employing donor-acceptor cyclopropane(DAC)agents and Sc(OTf)_(3).The Lewis acid catalyst converts DAC into a formal 1,3-zwitterionic species that in turn activates thioglycosides to furnish a glycosyl 1,4-zwitterionic intermediate,interconverting with reactive glycosyl oxocarbenium in the solution with reversible leaving-group dissociation.This activation method effectively promotes glycosylation reactions between both armed and disarmed thioglycosides and structurally diverse acceptors,affording oligosaccharides with satisfactory yields.The usefulness of our activation method has been demonstrated by the mechanism-inspired 2,4-dinitrobenzenesulfonyl(DNs)group directed S_(N)2-like glycosylation and the facile preparation of both linear and branched trisaccharides in one pot via controlled sequential activation of thioglycoside donors.
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.
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.
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%.
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.
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.
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supported by the National Natural Science Foundation of China(31930086 and 32172642)the National Key Research and Development(R&D)Program of China(2016YFD0400902 and 2021YFD2100505).
文摘Light is a fundamental environmental factor for living organisms on earth—not only as a primary energy source but also as an informational signal.In fungi,light can be used as an indicator for both time and space to control important physiological and morphological responses.Botrytis cinerea(B.cinerea)is a devastating phytopathogenic fungus that exploits light cues to optimize virulence and the balance between conidiation and sclerotia development,thereby improving its dispersal and survival in ecosystems.However,the components and mechanisms underlying these processes remain obscure.Here,we identify a novel light-signaling component in B.cinerea,BcCfaS,which encodes a putative cyclopropane fatty-acyl-phospholipid synthase.BcCfaS is strongly induced by light at the transcriptional level and plays a crucial role in regulating photomorphogenesis.Deletion of BcCfaS results in reduced vegetative growth,altered colony morphology,impaired sclerotial development,and enhanced conidiation in a lightdependent manner.Moreover,the mutant exhibits serious defects in stress response and virulence on the host.Based on a lipidomics analysis,a number of previously unknown fungal lipids and many BcCfaS-regulated lipids are identified in B.cinerea,including several novel phospholipids and fatty acids.Importantly,we find that BcCfaS controls conidiation and sclerotial development by positively regulating methyl jasmonate(MeJA)synthesis to activate the transcription of light-signaling components,revealing for the first time the metabolic base of photomorphogenesis in fungi.Thus,we propose that BcCfaS serves as an integration node for light and lipid metabolism,thereby providing a regulatory mechanism by which fungi adapt their development to a changing light environment.These new findings provide an important target for antifungal design to prevent and control fungal disease.
文摘Inspired by the anti-pancreatic promising results of our novel aminated cyclopropylmethylphosphonate compounds, an in vitro anti-prostate cancer activity exploration of these compounds was carried out on human prostate cancer cell line PC-3, and showed potent inhibiting activity at low micromolar concentrations (with an IC50 of approximately 45 μM).
基金supported by the National Natural Science Foundation of China (No. 22225101)Fundamental Research Funds for the Central Universities (No. 20720210003)。
文摘The reactions of halocarbenes with pre-aromatic ketones 1, 2 resulted in cyclopropanation and deoxygenation products. The varying product ratio could be accounted for by a mechanism involving the carbonyl ylide intermediate.
