A series of novel 1,2,4-oxadiazole-containing N-pyridylpyrazole derivatives 12 a-h were efficiently synthesized with pivaldehyde,pyridylpyrazole carboxylic acid and arylamine as raw materials via 1,3-dipolar cycloaddi...A series of novel 1,2,4-oxadiazole-containing N-pyridylpyrazole derivatives 12 a-h were efficiently synthesized with pivaldehyde,pyridylpyrazole carboxylic acid and arylamine as raw materials via 1,3-dipolar cycloaddition.Their structures were identified by melting points,1 H NMR,13 C NMR and elemental analysis or HRMS.The exploration on the single-crystal structures of 12 c and 12 g revealed the stereochemical and substituent oriental characteristics,and the relevance of the structure and the reaction activity of this type of compounds.The preliminary bioassays indicated that several compounds had good insecticidal activities,among which 12 c showed a lethality rate of 80%towards Mythimna separata Walker at 200μg/mL;some of the compounds exhibited favorable fungicidal activities at 50μg/mL against Physalospora piricola,Rhizoctonia cereal,Sclerotinia sclerotiorum,etc.Among which,12 a,12 b,12 c and 12 h could be considered as new fungicidal leading compounds for further structural optimization.These discoveries along with the structure-activity relationship analysis in this paper will provide useful guidance for the innovative studies on new pyridylpyrazole derivatives and their applications in agrochemical area.展开更多
Two calix[4]arene derivatives containing 1,2,3-triazole moiety were synthesized via K2CO3-catalyzed1,3-dipolar cycloaddition reaction between calix[4]arene-based azide and active methylene compounds in good yields.The...Two calix[4]arene derivatives containing 1,2,3-triazole moiety were synthesized via K2CO3-catalyzed1,3-dipolar cycloaddition reaction between calix[4]arene-based azide and active methylene compounds in good yields.The structures of the two compounds synthesized herein were fully confirmed by 1HNMR,,（13）C NMR,and MS（ESI）.The thermal analysis showed that the mass losses of the synthesized compounds 4 and 5 containing 1,2,3-triazole groups are similar to each other.展开更多
1,4-Addition reaction of Grignard's reagent to 5-methoxy-2(5H)-furanone 1 was accomplished. which provided a new possible route for synthesizing beta -alkyl-Y-alkyloxy-Y-butyrolactone. A novel concise method of pr...1,4-Addition reaction of Grignard's reagent to 5-methoxy-2(5H)-furanone 1 was accomplished. which provided a new possible route for synthesizing beta -alkyl-Y-alkyloxy-Y-butyrolactone. A novel concise method of preparing fused heterocyclic compounds was offered by 1,3-dipolar cycloaddition reaction of silyl nitronates to 1.展开更多
1 Introduction Fullerene has received considerable attention and a great researching interest due to its unique structure and interesting properties[1―3]. Many functional groups have been introduced, often region- or...1 Introduction Fullerene has received considerable attention and a great researching interest due to its unique structure and interesting properties[1―3]. Many functional groups have been introduced, often region- or stereo-selectively, for tuning the physical properties of C60and for constructing supramoleculararchitectures^[4-6].展开更多
Cu-catalyzed endo-selective asymmetric 1,3-dipolar cycloaddition of azomethine ylides with ethenesulfonyl fluorides(ESFs) was successfully developed, this protocol provided an efficient and facile method to a wide ran...Cu-catalyzed endo-selective asymmetric 1,3-dipolar cycloaddition of azomethine ylides with ethenesulfonyl fluorides(ESFs) was successfully developed, this protocol provided an efficient and facile method to a wide range of chiral pyrrolidine-3-sulfonyl fluorides with good to excellent results(up to 87% yield,>20:1 dr, 94% ee). Some other chiral sulfonyl derivatives, such as sulfonamide and sulfonate, were easily accessible through simple transformations with high yields, which demonstrated that the cycloaddition products could be synthetically useful in the sulfur(VI) fluoride exchange(Su FEx) chemistry.展开更多
The 1,3-dipolar cycloaddition reactions of various substituted ynamines with hydrazoic acid were theoretically investigated with the high-accuracy CBS-QB3 method. Two regioisomers, 4-amine, and 5-amine substituted add...The 1,3-dipolar cycloaddition reactions of various substituted ynamines with hydrazoic acid were theoretically investigated with the high-accuracy CBS-QB3 method. Two regioisomers, 4-amine, and 5-amine substituted adducts, were obtained, with the former as the preferred yield. This regioselectivity is rationalized by the frontier molecular orbital theory. The reactivity and synchronicity are enhanced with the increase of the electron-withdrawing character of the substitute on ynamine fragment. The calculations also show that the effect of solvent increases the activation energy, and the reaction becomes even harder in polar solvent.展开更多
The first example of stereoconvergent 1,3-dipolar cycloaddition of nitrile oxides and nitrile imines with E/Z isomeric mixture of electron-deficient olefins is reported,delivering isoxazolines and pyrazolines bearing ...The first example of stereoconvergent 1,3-dipolar cycloaddition of nitrile oxides and nitrile imines with E/Z isomeric mixture of electron-deficient olefins is reported,delivering isoxazolines and pyrazolines bearing two vicinal stereogenic tertiary and trifluoromethylated quaternary carbon centers with perfect regioand diastereoselectivities.The possibility of concerted cycloaddition/epimerization sequence under basic condition to form the thermodynamically stable diastereomers is excluded through some control experiments and DFT calculations,and a stepwise mechanism is proposed.展开更多
The 1,3-dipolar cycloaddition reaction of dimethyl hex-2-en-4-ynedioate with azomethine ylides derived from reaction of L-proline with various isatins in methanol selectively resulted in the formation of functionalize...The 1,3-dipolar cycloaddition reaction of dimethyl hex-2-en-4-ynedioate with azomethine ylides derived from reaction of L-proline with various isatins in methanol selectively resulted in the formation of functionalized spiro[indoline-3,3’-pyrrolizine]acrylates as main products and spiro[indoline-3,3’-pyrrolizine]propiolates as minor products.This result indicated that the electron-deficient alkyne has higher reactivity than that of electron-deficient alkene in 1,3-dipolar cycloaddition reaction.展开更多
5-(1-Menthyloxy)-2(5-H)-furanone is used as s chiral dipolarophile for thermal asymmetric 1,3-dipolar cycloaddition reaction with C-phenyl-N-phenyl nitrone to give the diastereomerically pure cycloaddition product.
The 1.3-dipolar cycloaddition reaction of 2-trifluoromethyl- oxazolone and the activated carbon-carbon multiple bond was studied and gave a convenient way to synthesize 2-trifluoromethylpyrrole derivatives.
1, 3 Dipolar cycloaddition reaction between vinyl acetate and 3-hydroxypyridiniun betaine was performed under solid-liquid phase transfer catalytic condition, This reaction has been successfully used on the synthesis ...1, 3 Dipolar cycloaddition reaction between vinyl acetate and 3-hydroxypyridiniun betaine was performed under solid-liquid phase transfer catalytic condition, This reaction has been successfully used on the synthesis of an analogue of Bao-Gong-Teng A.展开更多
Asymmetric 1,3-dipolar cycloaddihon of the chiral nitronic esters with acrylate giving the enantiomerically pure novel chiral bisheterocyclic compounds is describcd
The mechanism and regioselectivity of 1,3-dipolar cycloaddition of N-[methyl]-C-[5-nitro-2-furyl] nitrilimine with dimethyl 7-oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylate were investigated using activation energ...The mechanism and regioselectivity of 1,3-dipolar cycloaddition of N-[methyl]-C-[5-nitro-2-furyl] nitrilimine with dimethyl 7-oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylate were investigated using activation energy calculations and density functional theory-based reactivity indexes. The reaction proceeds by an asynchronous concerted mechanism. The calculations are performed at the B3LYP/6-31G（d） level of theory and the obtained results are in agreement with experimental outcome.展开更多
facile one-step method is presented for the synthesis of indolizines in moder-ate to high yields by reaction of pyridinium, quinolinium and isoquinolinium ylideswith acrylonitrile, methyl acrylate and diethyl maleate ...facile one-step method is presented for the synthesis of indolizines in moder-ate to high yields by reaction of pyridinium, quinolinium and isoquinolinium ylideswith acrylonitrile, methyl acrylate and diethyl maleate respectively in the presenceof tetrakis-pyridino-cobalt(Ⅱ)dichromate (TPCD) in DMF.展开更多
Heating a mixture of 1, 3-diiodo-1 ,1,3, 3-tetrafluoropropane (2), K2CO3, pyridinium bromides (3) in CH3CN at 65℃ for 10 h gives the corresponding trifluoromethylindolizines.
The 1,3-dipolar cycloaddition of an azomethine ylide generated by a decarboxylative route from sarcosine and acenaphthenequinone to 7-arylmethylidene-3-aryl-3,4-dihydro-2H-thiazolo[3,2-aJ[1,3,5]triazin-6（7H）-ones af...The 1,3-dipolar cycloaddition of an azomethine ylide generated by a decarboxylative route from sarcosine and acenaphthenequinone to 7-arylmethylidene-3-aryl-3,4-dihydro-2H-thiazolo[3,2-aJ[1,3,5]triazin-6（7H）-ones afforded novel dispiro[acenaphthylene-1,2’-pyrrolidine]-3＇,7″-[1,3]thiazolo[3,2-a][1,3,5]triazines in moderate yields. The structures of the products were determined and characterized thoroughly by NMR, MS, IR, elemental analysis and X-ray crystallographic analysis. The results of experiment indicated that this 1,3-dipolar cycloaddition proceeded with high stereoselectivity and regioselectivity.展开更多
A highly efficient and environmentally benign 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines with 5-alkenyl thiazolones and 2-arylidenindane-1,3-diones is developed for the construction of congested quatern...A highly efficient and environmentally benign 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines with 5-alkenyl thiazolones and 2-arylidenindane-1,3-diones is developed for the construction of congested quaternary spiro-carbon centers.All these transformations can be smoothly performed in ethanol at room temperature,providing a catalyst-free and atom-economical access to diversely substituted novel isoquinoline-fused spirocycles in almost quantitative yields with high diastereoselectivities.The promising anti-tumor activity of these structurally novel spirocyclic compounds is reported as well.展开更多
Asymmetric 1,3-dipolar cycloaddition of methyl a-fluoroacrylate with azomethine ylides for the construction of optically active fluorinated pyrrolidines bearing one unique fluorinated quaternary and two tertiary stere...Asymmetric 1,3-dipolar cycloaddition of methyl a-fluoroacrylate with azomethine ylides for the construction of optically active fluorinated pyrrolidines bearing one unique fluorinated quaternary and two tertiary stereogenic cen- ters has been achieved with Cu（CH3CN）4BF4/TF-BiphamPhos complexes for the first time. This catalytic system performs well over a broad scope of substrates, providing the synthetically useful adducts in good yields and excel- lent diastereoselectivities and good to high enantioselectivities.展开更多
基金supported by the National Natural Science Foundation of China(No.21772103)Tianjin Natural Science Foundation(No.17JCYBJC19900)the National Key Research and Development Program of China(No.2017YFD0200505)。
文摘A series of novel 1,2,4-oxadiazole-containing N-pyridylpyrazole derivatives 12 a-h were efficiently synthesized with pivaldehyde,pyridylpyrazole carboxylic acid and arylamine as raw materials via 1,3-dipolar cycloaddition.Their structures were identified by melting points,1 H NMR,13 C NMR and elemental analysis or HRMS.The exploration on the single-crystal structures of 12 c and 12 g revealed the stereochemical and substituent oriental characteristics,and the relevance of the structure and the reaction activity of this type of compounds.The preliminary bioassays indicated that several compounds had good insecticidal activities,among which 12 c showed a lethality rate of 80%towards Mythimna separata Walker at 200μg/mL;some of the compounds exhibited favorable fungicidal activities at 50μg/mL against Physalospora piricola,Rhizoctonia cereal,Sclerotinia sclerotiorum,etc.Among which,12 a,12 b,12 c and 12 h could be considered as new fungicidal leading compounds for further structural optimization.These discoveries along with the structure-activity relationship analysis in this paper will provide useful guidance for the innovative studies on new pyridylpyrazole derivatives and their applications in agrochemical area.
基金the financial supports of the National Natural Science Foundation of China(No.21102003)Scientific Research Foundation for the Introduction of Talent and Young Teachers Scientific Research Foundation of Anhui University of Science & Technology(Nos.11214,2012QNY27)
文摘Two calix[4]arene derivatives containing 1,2,3-triazole moiety were synthesized via K2CO3-catalyzed1,3-dipolar cycloaddition reaction between calix[4]arene-based azide and active methylene compounds in good yields.The structures of the two compounds synthesized herein were fully confirmed by 1HNMR,,（13）C NMR,and MS（ESI）.The thermal analysis showed that the mass losses of the synthesized compounds 4 and 5 containing 1,2,3-triazole groups are similar to each other.
基金This work was supported by the NNSFC (No.29672004).
文摘1,4-Addition reaction of Grignard's reagent to 5-methoxy-2(5H)-furanone 1 was accomplished. which provided a new possible route for synthesizing beta -alkyl-Y-alkyloxy-Y-butyrolactone. A novel concise method of preparing fused heterocyclic compounds was offered by 1,3-dipolar cycloaddition reaction of silyl nitronates to 1.
基金Supported by the National Natural Science Foundation of China(No.20402002)the Natural Science Foundation of Fujian Province,China (No.211J01031)+1 种基金the Project of Fujian Provincial Department of Education,China(No.JA11044)the Program for Excellent Young Researchers in Universities of Fujian Province,China(No.JA10056)
文摘1 Introduction Fullerene has received considerable attention and a great researching interest due to its unique structure and interesting properties[1―3]. Many functional groups have been introduced, often region- or stereo-selectively, for tuning the physical properties of C60and for constructing supramoleculararchitectures^[4-6].
基金the financial support from the National Natural Science Foundation of China (Nos. 21772147, 22071186, 22071187)Natural Science Foundation of Hubei Province (No. 2020CFA036)+1 种基金Natural Science Foundation of Jiangsu Province (No. SKB2019041078)The Program of Introducing Talents of Discipline to Universities of China (111 Project) is also appreciated。
文摘Cu-catalyzed endo-selective asymmetric 1,3-dipolar cycloaddition of azomethine ylides with ethenesulfonyl fluorides(ESFs) was successfully developed, this protocol provided an efficient and facile method to a wide range of chiral pyrrolidine-3-sulfonyl fluorides with good to excellent results(up to 87% yield,>20:1 dr, 94% ee). Some other chiral sulfonyl derivatives, such as sulfonamide and sulfonate, were easily accessible through simple transformations with high yields, which demonstrated that the cycloaddition products could be synthetically useful in the sulfur(VI) fluoride exchange(Su FEx) chemistry.
基金Ⅴ. ACKNOWLEDGMENT This work was supported by the National Natural Science Foundation of China （No.20833008）.
文摘The 1,3-dipolar cycloaddition reactions of various substituted ynamines with hydrazoic acid were theoretically investigated with the high-accuracy CBS-QB3 method. Two regioisomers, 4-amine, and 5-amine substituted adducts, were obtained, with the former as the preferred yield. This regioselectivity is rationalized by the frontier molecular orbital theory. The reactivity and synchronicity are enhanced with the increase of the electron-withdrawing character of the substitute on ynamine fragment. The calculations also show that the effect of solvent increases the activation energy, and the reaction becomes even harder in polar solvent.
基金the financial support for this investigation from the National Natural Science Foundation of China(Nos.21772151,22072111)the Fundamental Research Funds for Central Universities(No.WUT:2021IVA121).
文摘The first example of stereoconvergent 1,3-dipolar cycloaddition of nitrile oxides and nitrile imines with E/Z isomeric mixture of electron-deficient olefins is reported,delivering isoxazolines and pyrazolines bearing two vicinal stereogenic tertiary and trifluoromethylated quaternary carbon centers with perfect regioand diastereoselectivities.The possibility of concerted cycloaddition/epimerization sequence under basic condition to form the thermodynamically stable diastereomers is excluded through some control experiments and DFT calculations,and a stepwise mechanism is proposed.
基金financially supported by the National Natural Science Foundation of China(No.21572196)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China。
文摘The 1,3-dipolar cycloaddition reaction of dimethyl hex-2-en-4-ynedioate with azomethine ylides derived from reaction of L-proline with various isatins in methanol selectively resulted in the formation of functionalized spiro[indoline-3,3’-pyrrolizine]acrylates as main products and spiro[indoline-3,3’-pyrrolizine]propiolates as minor products.This result indicated that the electron-deficient alkyne has higher reactivity than that of electron-deficient alkene in 1,3-dipolar cycloaddition reaction.
文摘5-(1-Menthyloxy)-2(5-H)-furanone is used as s chiral dipolarophile for thermal asymmetric 1,3-dipolar cycloaddition reaction with C-phenyl-N-phenyl nitrone to give the diastereomerically pure cycloaddition product.
文摘The 1.3-dipolar cycloaddition reaction of 2-trifluoromethyl- oxazolone and the activated carbon-carbon multiple bond was studied and gave a convenient way to synthesize 2-trifluoromethylpyrrole derivatives.
基金the Natural Science Foundation of Guangdong province (No. 970154).
文摘1, 3 Dipolar cycloaddition reaction between vinyl acetate and 3-hydroxypyridiniun betaine was performed under solid-liquid phase transfer catalytic condition, This reaction has been successfully used on the synthesis of an analogue of Bao-Gong-Teng A.
文摘Asymmetric 1,3-dipolar cycloaddihon of the chiral nitronic esters with acrylate giving the enantiomerically pure novel chiral bisheterocyclic compounds is describcd
文摘The mechanism and regioselectivity of 1,3-dipolar cycloaddition of N-[methyl]-C-[5-nitro-2-furyl] nitrilimine with dimethyl 7-oxabicyclo[2,2,1]hepta-2,5-diene-2,3-dicarboxylate were investigated using activation energy calculations and density functional theory-based reactivity indexes. The reaction proceeds by an asynchronous concerted mechanism. The calculations are performed at the B3LYP/6-31G（d） level of theory and the obtained results are in agreement with experimental outcome.
文摘facile one-step method is presented for the synthesis of indolizines in moder-ate to high yields by reaction of pyridinium, quinolinium and isoquinolinium ylideswith acrylonitrile, methyl acrylate and diethyl maleate respectively in the presenceof tetrakis-pyridino-cobalt(Ⅱ)dichromate (TPCD) in DMF.
基金Project supported by the National Natural Science Foundation of China(Nos.20272076 and D20032010).
文摘Heating a mixture of 1, 3-diiodo-1 ,1,3, 3-tetrafluoropropane (2), K2CO3, pyridinium bromides (3) in CH3CN at 65℃ for 10 h gives the corresponding trifluoromethylindolizines.
基金Project supported by the National Natural Science Foundation of China （Nos. 20971041, 20803020, 20772027）, the Key Project of Chinese Ministry of Education （No. 210146） and Scientific Research Fund of Hunan Provincial Education Department （Nos. 09B032, 09C385, 09K081）.
文摘The 1,3-dipolar cycloaddition of an azomethine ylide generated by a decarboxylative route from sarcosine and acenaphthenequinone to 7-arylmethylidene-3-aryl-3,4-dihydro-2H-thiazolo[3,2-aJ[1,3,5]triazin-6（7H）-ones afforded novel dispiro[acenaphthylene-1,2’-pyrrolidine]-3＇,7″-[1,3]thiazolo[3,2-a][1,3,5]triazines in moderate yields. The structures of the products were determined and characterized thoroughly by NMR, MS, IR, elemental analysis and X-ray crystallographic analysis. The results of experiment indicated that this 1,3-dipolar cycloaddition proceeded with high stereoselectivity and regioselectivity.
基金We are thankful for the financial support from Ocean University of China(OUC),National Laboratory for Marine Science and Technology(QNLM)(Nos.LMDBCXRC201902,LMDBCXRC201903,tsqn201909056,tsqn202103152).The project is supported by the Fundamental Research Funds for the Central Universities.
文摘A highly efficient and environmentally benign 1,3-dipolar cycloaddition of C,N-cyclic azomethine imines with 5-alkenyl thiazolones and 2-arylidenindane-1,3-diones is developed for the construction of congested quaternary spiro-carbon centers.All these transformations can be smoothly performed in ethanol at room temperature,providing a catalyst-free and atom-economical access to diversely substituted novel isoquinoline-fused spirocycles in almost quantitative yields with high diastereoselectivities.The promising anti-tumor activity of these structurally novel spirocyclic compounds is reported as well.
文摘Asymmetric 1,3-dipolar cycloaddition of methyl a-fluoroacrylate with azomethine ylides for the construction of optically active fluorinated pyrrolidines bearing one unique fluorinated quaternary and two tertiary stereogenic cen- ters has been achieved with Cu（CH3CN）4BF4/TF-BiphamPhos complexes for the first time. This catalytic system performs well over a broad scope of substrates, providing the synthetically useful adducts in good yields and excel- lent diastereoselectivities and good to high enantioselectivities.
