The synthesis of new indoloannulated thiopyranethiones is reported. The key-step is a rhodium-catalyzed [2 + 2 + 2]-cycloaddition of alkynyl-ynamides with carbon disulfide to close the pyrrole and the thiopyranethione...The synthesis of new indoloannulated thiopyranethiones is reported. The key-step is a rhodium-catalyzed [2 + 2 + 2]-cycloaddition of alkynyl-ynamides with carbon disulfide to close the pyrrole and the thiopyranethione rings simultaneously. A violet idolothiopyrane thione or a mixture of the violet and a red isomer result from [RhCl(C<sub>8</sub>H<sub>14</sub>)<sub>2</sub>]<sub>2</sub>/3BINAP catalyzed cycloadditions, the regiochemistry is controlled by the substitution pattern on the alkynyl-ynamide.展开更多
Addition reaction of Grignard’s reagent to 5-methoxy-2(5H)-furanone 1 was accomplished, which provided a new possible route for synthesizing β-alkyl-γ-alkyloxy-γ-butyrolactone. A novel concise method of preparing ...Addition reaction of Grignard’s reagent to 5-methoxy-2(5H)-furanone 1 was accomplished, which provided a new possible route for synthesizing β-alkyl-γ-alkyloxy-γ-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
A double active center system, namely Salen-Cu(Ⅱ)@MIL-101(Cr), was successfully synthesized via the"ship in a bottle" approach, which acted as a bifunctional material for both capture and conversion of CO_2...A double active center system, namely Salen-Cu(Ⅱ)@MIL-101(Cr), was successfully synthesized via the"ship in a bottle" approach, which acted as a bifunctional material for both capture and conversion of CO_2 in a single process. For the first time, Salen-Cu(Ⅱ)@MIL-101(Cr) catalyst was developed for the synthesis of propylene carbonate from CO_2 and propylene oxide under room temperature and ambient pressure with a yield of 87.8% over 60 h. Furthermore, the reaction mechanism was also discussed.展开更多
Two kinds of bi-functional transition metal doped mesoporous materials(Fe-HMS and Fe-MCM-41) are prepared using one-step hydrothermal method and then treated with hydrochloric acid ethanol solution.The N2 adsorption a...Two kinds of bi-functional transition metal doped mesoporous materials(Fe-HMS and Fe-MCM-41) are prepared using one-step hydrothermal method and then treated with hydrochloric acid ethanol solution.The N2 adsorption and HRTEM results show that both of Fe-HMS and Fe-MCM-41 possess mesoporous structure. The UV–vis results suggest that the Fe species are mainly located within the framework. The basicity of as-prepared samples was studied by temperature programmed desorption using CO2 as probe molecule(CO2-TPD). The catalytic performance of Fe-HMS and Fe-MCM-41 in CO2 cycloaddition largely depends on the amount of the accessible basic sites. The acid–base active sites, framework Fe and PDDA species cooperatively catalyze the CO2 cycloaddition for the production of cyclic carbonates under the condition without any co-catalyst. The conversion of epichlorohydrin(ECH) is 97.4% and the selectivity of chloropropene carbonate is 92.9% under optimal conditions. The approximate rate constant of cycloaddition reaction of CO2 with ECH under optimum reaction temperature is calculated. It is worth noting that the Fe-HMS material shows superior reusability than Fe-MCM-41. In addition, this work provides a facile way on the synthesis of bi-functional acid–base heterogeneous catalyst with outstanding catalytic performance for the fixation of CO2.展开更多
Liquid crystalline polymers containing 1,2,3-triazole units as linking groups have been synthesized from the monomers containing triad ester diazide and flexible dialkyne ester by 1,3-cycloaddition reaction and were c...Liquid crystalline polymers containing 1,2,3-triazole units as linking groups have been synthesized from the monomers containing triad ester diazide and flexible dialkyne ester by 1,3-cycloaddition reaction and were characterized. Click reaction of azide and alkyne functionals catalyzed by Cu(I) yielded target polyesters with 1,2,3-triazole groups.The structure of the polymer was confirmed by spectral techniques.GPC analysis reveals that the polymers have moderate molecular weight with narrow distributio...展开更多
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 o...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
Formation of styrene carbonate (SC) by the cycloaddition of CO2 to styrene oxide (SO) catalysed by pyrrolidinopyridinium iodide (PPI) in combination with zinc halides (ZnCl2, ZnBr2 and ZnI2) was investigated. Complete...Formation of styrene carbonate (SC) by the cycloaddition of CO2 to styrene oxide (SO) catalysed by pyrrolidinopyridinium iodide (PPI) in combination with zinc halides (ZnCl2, ZnBr2 and ZnI2) was investigated. Complete conversion of the SO to SC was achieved in 3 h with 100% selectivity using 1/0.5 molar (PPI/ZnI2) catalyst ratio under mild reaction conditions i.e., 100℃ and 10 bar CO2 pressure. The synergistic effect of ZnI2 and PPI resulted in more than 7-fold increase in reaction rate than using PPI alone. The cycloaddition reaction demonstrated the first-order dependence with respect to the epoxide, CO2 and catalyst concentrations. Moreover, the kinetic and thermodynamic activation parameters of SC formation were determined using the Arrhenius and Eyring equations. The positive values of △H(42.8 kJ mol^-1) and △G(102.3 kJ mol^-1) revealed endergonic and chemically controlled nature of the reaction, whereas the large negative values of △S(-159.4 J mol^-1 K^-1) indicate a highly ordered activated complex at the transition state. The activation energy for SC formation catalyzed by PPI alone was found to be 73.2 kJ mol^-1 over a temperature range of 100-140℃, which was reduced to 46.1 kJ mol^-1 when using PPI in combination with ZnI2 as a binary catalyst. Based on the kinetic study, a synergistic acid-based reaction mechanism was proposed.展开更多
The [4+3] cycloaddition of the 6-substituted-2-chlorocyclohexanone and furans under the Fohlish condihons (Et3N in CF3CH2OH) has been accomplished to give tricyclic cycloadducts with good yields.
An unexpected tricyclic compound 2,3,3a,4,5,9b－hexahydrophenylfuro [3,2-c]quinoline 4 and its aromatized product 6 were obtained when the cycloaddtion of imine 1 and substituted norbornene 2 was carried out in THF wi...An unexpected tricyclic compound 2,3,3a,4,5,9b－hexahydrophenylfuro [3,2-c]quinoline 4 and its aromatized product 6 were obtained when the cycloaddtion of imine 1 and substituted norbornene 2 was carried out in THF with a catalytic amount of boron trifluoride．The structures of the products were determined by spectral data, and the mechanism of reaction was substantiated by the imitation reaction．展开更多
A new synthetic method is described here to obtain α, β-unsaturated ketones through alkenes through a sequence involving f (1) cycloaddition of alkenes with dichloroketene, (2) dechlorination of adducts, (3)acidprom...A new synthetic method is described here to obtain α, β-unsaturated ketones through alkenes through a sequence involving f (1) cycloaddition of alkenes with dichloroketene, (2) dechlorination of adducts, (3)acidpromoted ring-opening isomerization ofcyclobutanones in CF3 CO2H.展开更多
This paper describes the construction of hemiacetal 2, the core of pseudolaric acid A via oxidative cleavage of acetonide 6 or 7 and enolization-hemiacetalization of aldehyde 8. A plausible general mechanism for the i...This paper describes the construction of hemiacetal 2, the core of pseudolaric acid A via oxidative cleavage of acetonide 6 or 7 and enolization-hemiacetalization of aldehyde 8. A plausible general mechanism for the intramolecular [4+3] cycloaddition of sulfoxide 4 to adduct 3 is suggested.展开更多
Lewis acid catalyzed cycloaddition reactions of N-arylideneaniline Ⅰ with 2,3-dihydrofuran Ⅱ gave a pair of epimers d1-2, 3, 3a, 4, 5, 9b-hexahydro-4-arylfuro [3,2-c]quinolines Ⅲ and Ⅲ) and a few of their correspo...Lewis acid catalyzed cycloaddition reactions of N-arylideneaniline Ⅰ with 2,3-dihydrofuran Ⅱ gave a pair of epimers d1-2, 3, 3a, 4, 5, 9b-hexahydro-4-arylfuro [3,2-c]quinolines Ⅲ and Ⅲ) and a few of their corresponding aromatized compounds Ⅳ.展开更多
Unprecedented cycloaddition reactions of azatrienes (1) with sulfene leading to the synthesis of functionalized thiazinedioxide derivatives (5) are described. The reactions were found be highly regioselective resultin...Unprecedented cycloaddition reactions of azatrienes (1) with sulfene leading to the synthesis of functionalized thiazinedioxide derivatives (5) are described. The reactions were found be highly regioselective resulting in the formation of only [4 + 2] cycloadducts.展开更多
文摘The synthesis of new indoloannulated thiopyranethiones is reported. The key-step is a rhodium-catalyzed [2 + 2 + 2]-cycloaddition of alkynyl-ynamides with carbon disulfide to close the pyrrole and the thiopyranethione rings simultaneously. A violet idolothiopyrane thione or a mixture of the violet and a red isomer result from [RhCl(C<sub>8</sub>H<sub>14</sub>)<sub>2</sub>]<sub>2</sub>/3BINAP catalyzed cycloadditions, the regiochemistry is controlled by the substitution pattern on the alkynyl-ynamide.
基金This work was supported by the NNSFC (No.29672004).
文摘Addition reaction of Grignard’s reagent to 5-methoxy-2(5H)-furanone 1 was accomplished, which provided a new possible route for synthesizing β-alkyl-γ-alkyloxy-γ-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 Key Projects for Fundamental R&D Program of China(2016YFB0600902)the NFSC of Tianjin(16JCZDJC36700 and 14JCQNJC03000)
文摘A double active center system, namely Salen-Cu(Ⅱ)@MIL-101(Cr), was successfully synthesized via the"ship in a bottle" approach, which acted as a bifunctional material for both capture and conversion of CO_2 in a single process. For the first time, Salen-Cu(Ⅱ)@MIL-101(Cr) catalyst was developed for the synthesis of propylene carbonate from CO_2 and propylene oxide under room temperature and ambient pressure with a yield of 87.8% over 60 h. Furthermore, the reaction mechanism was also discussed.
基金financial support from the Program for New Century Excellent Talents in University(NCET-040270)。
文摘Two kinds of bi-functional transition metal doped mesoporous materials(Fe-HMS and Fe-MCM-41) are prepared using one-step hydrothermal method and then treated with hydrochloric acid ethanol solution.The N2 adsorption and HRTEM results show that both of Fe-HMS and Fe-MCM-41 possess mesoporous structure. The UV–vis results suggest that the Fe species are mainly located within the framework. The basicity of as-prepared samples was studied by temperature programmed desorption using CO2 as probe molecule(CO2-TPD). The catalytic performance of Fe-HMS and Fe-MCM-41 in CO2 cycloaddition largely depends on the amount of the accessible basic sites. The acid–base active sites, framework Fe and PDDA species cooperatively catalyze the CO2 cycloaddition for the production of cyclic carbonates under the condition without any co-catalyst. The conversion of epichlorohydrin(ECH) is 97.4% and the selectivity of chloropropene carbonate is 92.9% under optimal conditions. The approximate rate constant of cycloaddition reaction of CO2 with ECH under optimum reaction temperature is calculated. It is worth noting that the Fe-HMS material shows superior reusability than Fe-MCM-41. In addition, this work provides a facile way on the synthesis of bi-functional acid–base heterogeneous catalyst with outstanding catalytic performance for the fixation of CO2.
文摘Liquid crystalline polymers containing 1,2,3-triazole units as linking groups have been synthesized from the monomers containing triad ester diazide and flexible dialkyne ester by 1,3-cycloaddition reaction and were characterized. Click reaction of azide and alkyne functionals catalyzed by Cu(I) yielded target polyesters with 1,2,3-triazole groups.The structure of the polymer was confirmed by spectral techniques.GPC analysis reveals that the polymers have moderate molecular weight with narrow distributio...
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supported by the Engineering and Physical Science Research Council (EPSRC) funding for Sustainable Polymers (Project reference EP/L017393/1)
文摘Formation of styrene carbonate (SC) by the cycloaddition of CO2 to styrene oxide (SO) catalysed by pyrrolidinopyridinium iodide (PPI) in combination with zinc halides (ZnCl2, ZnBr2 and ZnI2) was investigated. Complete conversion of the SO to SC was achieved in 3 h with 100% selectivity using 1/0.5 molar (PPI/ZnI2) catalyst ratio under mild reaction conditions i.e., 100℃ and 10 bar CO2 pressure. The synergistic effect of ZnI2 and PPI resulted in more than 7-fold increase in reaction rate than using PPI alone. The cycloaddition reaction demonstrated the first-order dependence with respect to the epoxide, CO2 and catalyst concentrations. Moreover, the kinetic and thermodynamic activation parameters of SC formation were determined using the Arrhenius and Eyring equations. The positive values of △H(42.8 kJ mol^-1) and △G(102.3 kJ mol^-1) revealed endergonic and chemically controlled nature of the reaction, whereas the large negative values of △S(-159.4 J mol^-1 K^-1) indicate a highly ordered activated complex at the transition state. The activation energy for SC formation catalyzed by PPI alone was found to be 73.2 kJ mol^-1 over a temperature range of 100-140℃, which was reduced to 46.1 kJ mol^-1 when using PPI in combination with ZnI2 as a binary catalyst. Based on the kinetic study, a synergistic acid-based reaction mechanism was proposed.
文摘The [4+3] cycloaddition of the 6-substituted-2-chlorocyclohexanone and furans under the Fohlish condihons (Et3N in CF3CH2OH) has been accomplished to give tricyclic cycloadducts with good yields.
文摘An unexpected tricyclic compound 2,3,3a,4,5,9b－hexahydrophenylfuro [3,2-c]quinoline 4 and its aromatized product 6 were obtained when the cycloaddtion of imine 1 and substituted norbornene 2 was carried out in THF with a catalytic amount of boron trifluoride．The structures of the products were determined by spectral data, and the mechanism of reaction was substantiated by the imitation reaction．
文摘A new synthetic method is described here to obtain α, β-unsaturated ketones through alkenes through a sequence involving f (1) cycloaddition of alkenes with dichloroketene, (2) dechlorination of adducts, (3)acidpromoted ring-opening isomerization ofcyclobutanones in CF3 CO2H.
基金the National Natural Science Foundation of China.
文摘This paper describes the construction of hemiacetal 2, the core of pseudolaric acid A via oxidative cleavage of acetonide 6 or 7 and enolization-hemiacetalization of aldehyde 8. A plausible general mechanism for the intramolecular [4+3] cycloaddition of sulfoxide 4 to adduct 3 is suggested.
文摘Lewis acid catalyzed cycloaddition reactions of N-arylideneaniline Ⅰ with 2,3-dihydrofuran Ⅱ gave a pair of epimers d1-2, 3, 3a, 4, 5, 9b-hexahydro-4-arylfuro [3,2-c]quinolines Ⅲ and Ⅲ) and a few of their corresponding aromatized compounds Ⅳ.
文摘Unprecedented cycloaddition reactions of azatrienes (1) with sulfene leading to the synthesis of functionalized thiazinedioxide derivatives (5) are described. The reactions were found be highly regioselective resulting in the formation of only [4 + 2] cycloadducts.
