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
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 functionalized 1,10-dihydropyrrolo[1,2-a][1,10]phenanthroline derivatives were synthesized in good yields and with high diastereoselectivity by 1,3-dipolar cycloaddition reactions of N-phenacylphenanthrolinium bro...The functionalized 1,10-dihydropyrrolo[1,2-a][1,10]phenanthroline derivatives were synthesized in good yields and with high diastereoselectivity by 1,3-dipolar cycloaddition reactions of N-phenacylphenanthrolinium bromides or N-ethoxycarbonylmethylene phenanthrolinium bromide with various nitrostyrenes in acetonitrile at room temperature in the presence of triethvlamine,展开更多
The syntheses of a number of C-aryl-N-3-butenyl nitrones [aryl ring=4-CH_3O-phenyl (1a), phenyl(1b), 4-Cl-phenyl(1e), 4-Br-phenyl(1d), 4-NO2-phenyl(1e), 2-furyl (1f), 2-thienyl (1g), 2-pyrryl(1h)] and their thermochem...The syntheses of a number of C-aryl-N-3-butenyl nitrones [aryl ring=4-CH_3O-phenyl (1a), phenyl(1b), 4-Cl-phenyl(1e), 4-Br-phenyl(1d), 4-NO2-phenyl(1e), 2-furyl (1f), 2-thienyl (1g), 2-pyrryl(1h)] and their thermochemical reactions have been investigated. The thermocycloadditions of 1a-1h are regiospecific in forming a novel heterobicyclic ring system. Exo-aryl-1-aza-7-oxabicyclo- [2.2.1]heptane.展开更多
The 1,3-dipolar cycloaddition reactions of nitrilimine with thiazolo[3,2-a]pyrimidine derivatives was investigated. Bis-cycloadducts were obtained through a domino 1,3-dipolar cycloaddition/ring-opening/ring-opening/ ...The 1,3-dipolar cycloaddition reactions of nitrilimine with thiazolo[3,2-a]pyrimidine derivatives was investigated. Bis-cycloadducts were obtained through a domino 1,3-dipolar cycloaddition/ring-opening/ring-opening/ 1,3-dipolar cycloaddition processes. The structures of the products were characterized thoroughly by NMR, IR, MS, elemental analysis together with X-ray crystallographic analysis.展开更多
1,3-Dipolar cycloaddition to C70 of an azomethine ylide, which was generated in situ from refluxing a mixture of cyclohexanone and DL-valine in chlorobenzene under N2, afforded a monoadduct and a bisadduct. Even for l...1,3-Dipolar cycloaddition to C70 of an azomethine ylide, which was generated in situ from refluxing a mixture of cyclohexanone and DL-valine in chlorobenzene under N2, afforded a monoadduct and a bisadduct. Even for longer reaction time, however, only monoadduct waa obtained from the reaction of C70 with an azomethine ylide generated from refluxing a mixture of 2-undecanone and 2-aminoisobutyric acid in chlorobenzene under N2. The electrochemical properties of all the products were studied by cyclic voltammetry.展开更多
We report here a solid-phase synthesis of 1, 4-disubstituted 1, 2, 3-triazole using polystyrene-supported selenium resin. The resin used here not only works as a simple linker, but also assists the crucial α-alkylati...We report here a solid-phase synthesis of 1, 4-disubstituted 1, 2, 3-triazole using polystyrene-supported selenium resin. The resin used here not only works as a simple linker, but also assists the crucial α-alkylation reaction and selenoxide syn-elimimation, which ensures the purity of the products.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.
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.
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 National Natural Science Foundation of China，the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘The functionalized 1,10-dihydropyrrolo[1,2-a][1,10]phenanthroline derivatives were synthesized in good yields and with high diastereoselectivity by 1,3-dipolar cycloaddition reactions of N-phenacylphenanthrolinium bromides or N-ethoxycarbonylmethylene phenanthrolinium bromide with various nitrostyrenes in acetonitrile at room temperature in the presence of triethvlamine,
文摘The syntheses of a number of C-aryl-N-3-butenyl nitrones [aryl ring=4-CH_3O-phenyl (1a), phenyl(1b), 4-Cl-phenyl(1e), 4-Br-phenyl(1d), 4-NO2-phenyl(1e), 2-furyl (1f), 2-thienyl (1g), 2-pyrryl(1h)] and their thermochemical reactions have been investigated. The thermocycloadditions of 1a-1h are regiospecific in forming a novel heterobicyclic ring system. Exo-aryl-1-aza-7-oxabicyclo- [2.2.1]heptane.
基金Project supported by the National Natural Science Foundation of China （Nos. 20971041, 20803020, 20772027）, 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 reactions of nitrilimine with thiazolo[3,2-a]pyrimidine derivatives was investigated. Bis-cycloadducts were obtained through a domino 1,3-dipolar cycloaddition/ring-opening/ring-opening/ 1,3-dipolar cycloaddition processes. The structures of the products were characterized thoroughly by NMR, IR, MS, elemental analysis together with X-ray crystallographic analysis.
基金Project supported by the National Natural Science Foundation of China
文摘1,3-Dipolar cycloaddition to C70 of an azomethine ylide, which was generated in situ from refluxing a mixture of cyclohexanone and DL-valine in chlorobenzene under N2, afforded a monoadduct and a bisadduct. Even for longer reaction time, however, only monoadduct waa obtained from the reaction of C70 with an azomethine ylide generated from refluxing a mixture of 2-undecanone and 2-aminoisobutyric acid in chlorobenzene under N2. The electrochemical properties of all the products were studied by cyclic voltammetry.
基金the National Natural Science Foundation of China(No.20332060)the Natural Science Foundation of Zhejiang Province(No.Y405407).
文摘We report here a solid-phase synthesis of 1, 4-disubstituted 1, 2, 3-triazole using polystyrene-supported selenium resin. The resin used here not only works as a simple linker, but also assists the crucial α-alkylation reaction and selenoxide syn-elimimation, which ensures the purity of the products.
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.
