Imposing conformational constraints on sp3-rich structures is emerging as an important strategy for structural modification and optimization,which can improve the bioactivity of drugs.Herein,we report a visible-light-...Imposing conformational constraints on sp3-rich structures is emerging as an important strategy for structural modification and optimization,which can improve the bioactivity of drugs.Herein,we report a visible-light-induced photosensitized[2+2]homo-cycloaddition and cross-cycloaddition of cyclopropenes to synthesize tricyclo[3.1.0.0^(2,4)]hexanes as rigidified 3,3,6,6-tetrasubstituted cyclohexanes.Trifluoroacetylsilanes,previously known as trifluoromethyl siloxycarbene precursors,were used as photocatalysts for the first time.The mechanism study supports that the aggregation of cyclopropenes is important to promote their sensitization by trifluoroacetylsilanes through energy transfer.展开更多
Amorphous Ni B/γ Al 2O 3 catalyst 1 is prepared with chemical reduction by KBH 4 solution after wetness impregnation and desiccation at 70 ℃ first and then at 110 ℃ for thorough water removal. Its higher catalytic ...Amorphous Ni B/γ Al 2O 3 catalyst 1 is prepared with chemical reduction by KBH 4 solution after wetness impregnation and desiccation at 70 ℃ first and then at 110 ℃ for thorough water removal. Its higher catalytic activity than amorphous Ni B/γ Al 2O 3 catalyst 2, prepared by conventional one step desiccation procedure at 110 ℃, is identified in liquid phase benzene hydrogenation to cyclohexane. Both catalysts are characterized by XRD and SEM, Ni B/γ Al 2O 3 catalyst 1 has a higher active specific surface area and dispersion degree, which can be assigned to more effective distribution of nickel salt over the support during desiccation, thus resulting in its superior activity in benzene hydrogenation.展开更多
As an endothermic hydrocarbon fuel,pentacyclo[6.3.1.02,7.03,5.09,11]dodecane has been synthesized from dicyclopentadiene catalyzed by Zn(Cu).Effects of catalyst ingredients,catalyst amount,temperature on yield of titl...As an endothermic hydrocarbon fuel,pentacyclo[6.3.1.02,7.03,5.09,11]dodecane has been synthesized from dicyclopentadiene catalyzed by Zn(Cu).Effects of catalyst ingredients,catalyst amount,temperature on yield of titled compound were investigated.The optimal conditions were: 15 ℃,n(DCPD)∶n(Zn(Cu))∶n(CH2I2)=1∶4∶8.Under the above conditions the conversion of dicyclopentadiene was 99.7% and the yield of pentacyclodocane reached 91.5%.展开更多
基金National Key R&D Program of China(No.2022YFA1506100)National Natural Science Foundation of China(Nos.22471201,21901191)+1 种基金Fundamental Research Funds for the Central Universities(No.2042023kf0202)Wuhan University for financial support。
文摘Imposing conformational constraints on sp3-rich structures is emerging as an important strategy for structural modification and optimization,which can improve the bioactivity of drugs.Herein,we report a visible-light-induced photosensitized[2+2]homo-cycloaddition and cross-cycloaddition of cyclopropenes to synthesize tricyclo[3.1.0.0^(2,4)]hexanes as rigidified 3,3,6,6-tetrasubstituted cyclohexanes.Trifluoroacetylsilanes,previously known as trifluoromethyl siloxycarbene precursors,were used as photocatalysts for the first time.The mechanism study supports that the aggregation of cyclopropenes is important to promote their sensitization by trifluoroacetylsilanes through energy transfer.
文摘Amorphous Ni B/γ Al 2O 3 catalyst 1 is prepared with chemical reduction by KBH 4 solution after wetness impregnation and desiccation at 70 ℃ first and then at 110 ℃ for thorough water removal. Its higher catalytic activity than amorphous Ni B/γ Al 2O 3 catalyst 2, prepared by conventional one step desiccation procedure at 110 ℃, is identified in liquid phase benzene hydrogenation to cyclohexane. Both catalysts are characterized by XRD and SEM, Ni B/γ Al 2O 3 catalyst 1 has a higher active specific surface area and dispersion degree, which can be assigned to more effective distribution of nickel salt over the support during desiccation, thus resulting in its superior activity in benzene hydrogenation.
文摘As an endothermic hydrocarbon fuel,pentacyclo[6.3.1.02,7.03,5.09,11]dodecane has been synthesized from dicyclopentadiene catalyzed by Zn(Cu).Effects of catalyst ingredients,catalyst amount,temperature on yield of titled compound were investigated.The optimal conditions were: 15 ℃,n(DCPD)∶n(Zn(Cu))∶n(CH2I2)=1∶4∶8.Under the above conditions the conversion of dicyclopentadiene was 99.7% and the yield of pentacyclodocane reached 91.5%.
