Asymmetric intramolecular cyclopropanation of allylic diazoacetate was investigated using a chiral (β-diketone)-copper complex as catalyst, excellent yield and enantioselectivity were achieved. Some factors influenci...Asymmetric intramolecular cyclopropanation of allylic diazoacetate was investigated using a chiral (β-diketone)-copper complex as catalyst, excellent yield and enantioselectivity were achieved. Some factors influencing enantioselectivity were discussed.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
A straightforward and efficient protocol for dearomatizing indoles is described.The reaction,catalyzed by an inexpensive Co(III)/Zn(II)catalyst,starts from easily accessible N‐pyrimidinyl indoles and ene‐yne ketones...A straightforward and efficient protocol for dearomatizing indoles is described.The reaction,catalyzed by an inexpensive Co(III)/Zn(II)catalyst,starts from easily accessible N‐pyrimidinyl indoles and ene‐yne ketones.Mild reaction conditions,high diastereoselectivity,a broad substrate scope,effective functional group tolerance,and reasonable to remarkable yields were observed.展开更多
Four chiral 1,1?bis(oxazolinyl)ferrocenes(1a-1d) have been prepared and used as ligands in the copper catalyzed asymmetric cyclopropanation of styrene with ethyl diazoacetate (EDA) and the magnesium catalyzed Diels-Al...Four chiral 1,1?bis(oxazolinyl)ferrocenes(1a-1d) have been prepared and used as ligands in the copper catalyzed asymmetric cyclopropanation of styrene with ethyl diazoacetate (EDA) and the magnesium catalyzed Diels-Alder reaction between 3-acryloyl-2-oxazolidinone and cyclopentadiene. Enantioselectivities up to 24% and 41%, respectively, for cyclopropanation and Diels-Alder reaction were observed.展开更多
In order to have efficient and highly stereoselective cyclopropanating reagents, the cyclopropabation reaction of ethylene promoted with Samarium（Ⅱ） carbenoid [Simmons-Smith（SS）reagent] were studied by means of B...In order to have efficient and highly stereoselective cyclopropanating reagents, the cyclopropabation reaction of ethylene promoted with Samarium（Ⅱ） carbenoid [Simmons-Smith（SS）reagent] were studied by means of B3LYP hybrid density functional method. The geometries for reactants, transition states and products are completely optimized. All transition states were verified by the vibrational analysis and the intrinsic reaction coordinate （IRC） calculations. The results showed that, identical with the lithium carbenoid, CH3SmCH2X（X=Cl, Br and Ⅰ） can fairly react with ethylene via both methylene transfer pathway （pathway A） and carbometalation pathway （pathway B）. And the cyclopropanation reaction via methylene transfer pathway proceeds with a lower barrier and at lower temperatures.展开更多
Four stereoisomers of a copper-(Schiff-base) complex with double chiral centers were applied to catalyze the asymmetric cyclopropanation. Two of the stereoisomers were also efficient catalysts affording high enantiom...Four stereoisomers of a copper-(Schiff-base) complex with double chiral centers were applied to catalyze the asymmetric cyclopropanation. Two of the stereoisomers were also efficient catalysts affording high enantiomeric excess of up to 91.8%. A mechanism that predicts the observed results accurately was proposed.展开更多
Several cyclopropanation catalysts for the synthesis of 3(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylates have been studied in this paper. Owing to electron deficiency of 1,1-dichloro-4-methyl-1,3-pentadiene, ...Several cyclopropanation catalysts for the synthesis of 3(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylates have been studied in this paper. Owing to electron deficiency of 1,1-dichloro-4-methyl-1,3-pentadiene, yield of this reaction is rather law compared with that of 2,5-dimethyl-2,4-pentadiene, Of all catalysts concerned. yield ranged from 25.1% to 47.2%.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 chiral β-diketone Cu (Ⅱ) catalyst was synthesized and used for the asymmetric cyclopropanation of styrene with diazoester. A high optical yield (~90%) was achieved. The effect of the structure of substrate on ...A new chiral β-diketone Cu (Ⅱ) catalyst was synthesized and used for the asymmetric cyclopropanation of styrene with diazoester. A high optical yield (~90%) was achieved. The effect of the structure of substrate on the enantioselectivity was studied. Both chendcal yield and optical yield being reduced when the steric bulky substrate was employed. The reaction mechanism and the chiral model of the transition state are under fufther investigation.展开更多
Nine copper compounds are used for catalyzing the cyclopropanation of 1-hexene/TME with alkyl diazoacetate.Cu(Salad)2 shows the highest yield for the reaction of TME at high temperature such as 100℃.The reaction of c...Nine copper compounds are used for catalyzing the cyclopropanation of 1-hexene/TME with alkyl diazoacetate.Cu(Salad)2 shows the highest yield for the reaction of TME at high temperature such as 100℃.The reaction of crude RDA with TME in 73.7% yield under the optimal condition is obtained.展开更多
Cyclopropanation of styrene with ethyl diazoacetate catalyzed by Pd(II) inionic liquid [omim][BF_4] was investigated. Palladium catalysts can be effectively immobilized inionic liquid. The catalysts PdCl_2 and cyclopa...Cyclopropanation of styrene with ethyl diazoacetate catalyzed by Pd(II) inionic liquid [omim][BF_4] was investigated. Palladium catalysts can be effectively immobilized inionic liquid. The catalysts PdCl_2 and cyclopalladated complex 2 contained in ionic liquid could berecycled for 6 and 7 times, respectively, without losing the efficiency.展开更多
A copper-catalyzed highly stereoselective cyclopropanation of 1,2-disubstituted olefins with α-nitrodiazo acetates has been developed, giving the desired products in up to 97 % yields, up to 〉99/1 dr and up to 98 % ...A copper-catalyzed highly stereoselective cyclopropanation of 1,2-disubstituted olefins with α-nitrodiazo acetates has been developed, giving the desired products in up to 97 % yields, up to 〉99/1 dr and up to 98 % ee, which provides an efficient access to the synthesis of optical active cyclopropane α-amino acids and unnatural α-amino acid derivatives.展开更多
A novel palladium-catalyzed oxidative cyclopropanation of enamides and norbornenes has been developed. The reaction proceeded through palladium-catalyzed vinyl C–H bond activation of enamides followed by two migrator...A novel palladium-catalyzed oxidative cyclopropanation of enamides and norbornenes has been developed. The reaction proceeded through palladium-catalyzed vinyl C–H bond activation of enamides followed by two migratory insertions, β-(N)H elimination and hydrolyzation cascade steps. The reaction tolerates a range of functional groups and provides an effective method for the synthesis of cyclopropane-fused norbornanes in good yields under mild conditions.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
A highly efficient asymmetric cyclopropanation of trisubstituted olefins with methyl diazoacetate has been developed in terms of an elaborate modified chiral bisoxazoline/copper complex as a catalyst. A broad scope of...A highly efficient asymmetric cyclopropanation of trisubstituted olefins with methyl diazoacetate has been developed in terms of an elaborate modified chiral bisoxazoline/copper complex as a catalyst. A broad scope of substrates is compatible with this catalyst system, including various trisubstituted olefins bearing different aryl-, fused aryl-and alkyl-substituents, providing an easy access to optically active 1,1-dimethyl cyclopropanes in good yields with excellent diastereo-and enantio-selectivity.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
An easy and efficient method for the synthesis of multisubstituted cyclopropane derivatives from electron-deficicent alkenes with 2-bromo-1,3-propanedione compounds was described.For this method,ethylα-cyanocinnamate...An easy and efficient method for the synthesis of multisubstituted cyclopropane derivatives from electron-deficicent alkenes with 2-bromo-1,3-propanedione compounds was described.For this method,ethylα-cyanocinnamate derivatives 1 andβ,β-dicyanostyrene derivatives 4 can all smoothly reacted with 2-bromo-1,3-propanedione compounds 2 to afford the corresponding multisubstituted cyclopropane derivatives 3 and 5 in good to excellent yields(up to 100%)promoted by anhydrous K3PO4 in DMF at room temperature,respectively.A possible mechanism of this reaction was proposed.Structures of all the products were confirmed by ^1H NMR,^13C NMR and HRMS.展开更多
An efficient synthesis of β-alkoxycarbonyl vinylsulfonium salts had been developed. Their reaction with indene-1,3-diones and other active methylene compounds provided cyclopropane carboxylates in good yields. A tent...An efficient synthesis of β-alkoxycarbonyl vinylsulfonium salts had been developed. Their reaction with indene-1,3-diones and other active methylene compounds provided cyclopropane carboxylates in good yields. A tentative reaction mechanism was proposed.展开更多
New chiral substituted 8-quinolinyl-oxazoline ligands have been synthesized and applied in the copper(I)-catalyzed asymmetric cyclopropanation of styrene with alkyl diazoacetates. The steric effect in the ligands play...New chiral substituted 8-quinolinyl-oxazoline ligands have been synthesized and applied in the copper(I)-catalyzed asymmetric cyclopropanation of styrene with alkyl diazoacetates. The steric effect in the ligands plays a significant role in the enantiocontrol in asymmetric cyclopropanation, while the electronic effect is less important.展开更多
文摘Asymmetric intramolecular cyclopropanation of allylic diazoacetate was investigated using a chiral (β-diketone)-copper complex as catalyst, excellent yield and enantioselectivity were achieved. Some factors influencing enantioselectivity were discussed.
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.
文摘A straightforward and efficient protocol for dearomatizing indoles is described.The reaction,catalyzed by an inexpensive Co(III)/Zn(II)catalyst,starts from easily accessible N‐pyrimidinyl indoles and ene‐yne ketones.Mild reaction conditions,high diastereoselectivity,a broad substrate scope,effective functional group tolerance,and reasonable to remarkable yields were observed.
文摘Four chiral 1,1?bis(oxazolinyl)ferrocenes(1a-1d) have been prepared and used as ligands in the copper catalyzed asymmetric cyclopropanation of styrene with ethyl diazoacetate (EDA) and the magnesium catalyzed Diels-Alder reaction between 3-acryloyl-2-oxazolidinone and cyclopentadiene. Enantioselectivities up to 24% and 41%, respectively, for cyclopropanation and Diels-Alder reaction were observed.
基金This work was supported by the Northwest Normal University Science Foundation of Gansu Province （No. NWNU-QN-2001-08）.
文摘In order to have efficient and highly stereoselective cyclopropanating reagents, the cyclopropabation reaction of ethylene promoted with Samarium（Ⅱ） carbenoid [Simmons-Smith（SS）reagent] were studied by means of B3LYP hybrid density functional method. The geometries for reactants, transition states and products are completely optimized. All transition states were verified by the vibrational analysis and the intrinsic reaction coordinate （IRC） calculations. The results showed that, identical with the lithium carbenoid, CH3SmCH2X（X=Cl, Br and Ⅰ） can fairly react with ethylene via both methylene transfer pathway （pathway A） and carbometalation pathway （pathway B）. And the cyclopropanation reaction via methylene transfer pathway proceeds with a lower barrier and at lower temperatures.
文摘Four stereoisomers of a copper-(Schiff-base) complex with double chiral centers were applied to catalyze the asymmetric cyclopropanation. Two of the stereoisomers were also efficient catalysts affording high enantiomeric excess of up to 91.8%. A mechanism that predicts the observed results accurately was proposed.
文摘Several cyclopropanation catalysts for the synthesis of 3(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylates have been studied in this paper. Owing to electron deficiency of 1,1-dichloro-4-methyl-1,3-pentadiene, yield of this reaction is rather law compared with that of 2,5-dimethyl-2,4-pentadiene, Of all catalysts concerned. yield ranged from 25.1% to 47.2%.
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A new chiral β-diketone Cu (Ⅱ) catalyst was synthesized and used for the asymmetric cyclopropanation of styrene with diazoester. A high optical yield (~90%) was achieved. The effect of the structure of substrate on the enantioselectivity was studied. Both chendcal yield and optical yield being reduced when the steric bulky substrate was employed. The reaction mechanism and the chiral model of the transition state are under fufther investigation.
文摘Nine copper compounds are used for catalyzing the cyclopropanation of 1-hexene/TME with alkyl diazoacetate.Cu(Salad)2 shows the highest yield for the reaction of TME at high temperature such as 100℃.The reaction of crude RDA with TME in 73.7% yield under the optimal condition is obtained.
基金theFoundationofShanghaiScienceandTechnologyDevelopment (No .0 1JC140 0 2 )
文摘Cyclopropanation of styrene with ethyl diazoacetate catalyzed by Pd(II) inionic liquid [omim][BF_4] was investigated. Palladium catalysts can be effectively immobilized inionic liquid. The catalysts PdCl_2 and cyclopalladated complex 2 contained in ionic liquid could berecycled for 6 and 7 times, respectively, without losing the efficiency.
基金supported by the National Natural Science Foundation of China(21421091,21432011 and21272250)the Chinese Academy of Sciences
文摘A copper-catalyzed highly stereoselective cyclopropanation of 1,2-disubstituted olefins with α-nitrodiazo acetates has been developed, giving the desired products in up to 97 % yields, up to 〉99/1 dr and up to 98 % ee, which provides an efficient access to the synthesis of optical active cyclopropane α-amino acids and unnatural α-amino acid derivatives.
基金supported by the National Natural Science Foundation of China (NSFC-21622203, 21472147, 21702161)the China Postdoctoral Science Foundation Funded Project (2017M610644)Fund of Northwest University (334100036)
文摘A novel palladium-catalyzed oxidative cyclopropanation of enamides and norbornenes has been developed. The reaction proceeded through palladium-catalyzed vinyl C–H bond activation of enamides followed by two migratory insertions, β-(N)H elimination and hydrolyzation cascade steps. The reaction tolerates a range of functional groups and provides an effective method for the synthesis of cyclopropane-fused norbornanes in good yields under mild conditions.
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.
基金supported by the National Natural Science Foundation of China(21432011,21772224)Key Research Program of Frontier Sciences of Chinese Academy of Sciences(QYZDY-SSWSLH016)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20000000)the Youth Innovation Promotion Association CAS(2017301)the National Basic Research Program of China(2015CB856600)
文摘A highly efficient asymmetric cyclopropanation of trisubstituted olefins with methyl diazoacetate has been developed in terms of an elaborate modified chiral bisoxazoline/copper complex as a catalyst. A broad scope of substrates is compatible with this catalyst system, including various trisubstituted olefins bearing different aryl-, fused aryl-and alkyl-substituents, providing an easy access to optically active 1,1-dimethyl cyclopropanes in good yields with excellent diastereo-and enantio-selectivity.
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 Natural Science Foundation of Shaanxi Province,China(No.2009JM2001)the Innovation Foundation of Postgraduate Cultivation of Shaanxi Normal University,China(No.2008CXB009).
文摘An easy and efficient method for the synthesis of multisubstituted cyclopropane derivatives from electron-deficicent alkenes with 2-bromo-1,3-propanedione compounds was described.For this method,ethylα-cyanocinnamate derivatives 1 andβ,β-dicyanostyrene derivatives 4 can all smoothly reacted with 2-bromo-1,3-propanedione compounds 2 to afford the corresponding multisubstituted cyclopropane derivatives 3 and 5 in good to excellent yields(up to 100%)promoted by anhydrous K3PO4 in DMF at room temperature,respectively.A possible mechanism of this reaction was proposed.Structures of all the products were confirmed by ^1H NMR,^13C NMR and HRMS.
基金the National Natural Science Foundation of China (Nos. 21772240, 21472248)National Science and Technology Major Project of the Ministry of Science and Technology of China (No. 2017ZX09305010)+2 种基金Guangzhou Science Technology and Innovation Commission(No. 201707010210)Department of Science and Technology of Guangdong Province(Nos. 2017A020211011,2017A020211027)China Scholarship Council (No. 201608440090)
文摘An efficient synthesis of β-alkoxycarbonyl vinylsulfonium salts had been developed. Their reaction with indene-1,3-diones and other active methylene compounds provided cyclopropane carboxylates in good yields. A tentative reaction mechanism was proposed.
文摘New chiral substituted 8-quinolinyl-oxazoline ligands have been synthesized and applied in the copper(I)-catalyzed asymmetric cyclopropanation of styrene with alkyl diazoacetates. The steric effect in the ligands plays a significant role in the enantiocontrol in asymmetric cyclopropanation, while the electronic effect is less important.
