Ag_(2)CO_(3)-promoted dehydroxymethylative fluorination of aliphatic alcohols has been achieved with Selectfluor as both oxidant and fluorine source.The reaction involvesβ-fragmentation of primary alkoxy radicals,fol...Ag_(2)CO_(3)-promoted dehydroxymethylative fluorination of aliphatic alcohols has been achieved with Selectfluor as both oxidant and fluorine source.The reaction involvesβ-fragmentation of primary alkoxy radicals,followed by the fluorination of the resulting C-centered radical intermediates.The transformation proceeds under mild reaction conditions and exhibits a broad substrate scope,thus opening up a new entrance to the synthesis of fluorinated constructs includingα-fluoroimides and 1-fluoroalkyl benzoates as well as secondary and tertiary alkyl fluorides like versatile 2-fluoro-2-alkyl 1,3-propandiol derivatives.The divergent functionalization of the obtainedα-fluoroimides enables an efficient access to amine derivatives through C-F bond activation under the action of BF_(3)·OEt_(2).展开更多
[目的]探讨鳖甲寡肽I-C-F-6对乙醇诱导的小鼠慢性肝损伤的预防作用,并分析其可能的保护机制。[方法]将90只ICR小鼠随机分为正常对照组、模型组、寡肽低剂量组(0.12 mg/kg)、寡肽高剂量组(0.24 mg/kg)、阳性药组(240.00 mg/kg)。正常对...[目的]探讨鳖甲寡肽I-C-F-6对乙醇诱导的小鼠慢性肝损伤的预防作用,并分析其可能的保护机制。[方法]将90只ICR小鼠随机分为正常对照组、模型组、寡肽低剂量组(0.12 mg/kg)、寡肽高剂量组(0.24 mg/kg)、阳性药组(240.00 mg/kg)。正常对照组和模型组均皮下注射生理盐水(0.12 m L/kg);寡肽低剂量组和寡肽高剂量组分别皮下注射寡肽的生理盐水溶液(0.12 m L/kg);阳性药组灌胃还原型谷胱甘肽生理盐水溶液(0.12 m L/kg),同时除正常对照组外,其余4组给予灌胃40%乙醇(0.12 m L/kg),每日1次,连续16周。16周后,末次给乙醇12 h后处死小鼠采集血液样品和肝组织样品,测定血清谷丙转氨酶(ALT)、谷草转氨酶(AST)和碱性磷酸酶(AKP)的活力,肝组织超氧化物歧化酶(SOD)活力、丙二醛含量(MDA),单胺氧化酶(MAO)的活力,并进行病理组织学检查。[结果]鳖甲寡肽I-C-F-6使灌胃乙醇后小鼠体内ALT、AST、MDA、MAO、AKP的含量显著降低(P<0.05),肝组织匀浆中SOD的活力明显升高(P<0.05),肝脏病理损伤减轻。[结论]鳖甲寡肽I-C-F-6对小鼠慢性酒精性肝损伤具有一定的预防保护作用,其机制可能与抑制脂质过氧化,清除自由基,升高SOD的活力有关。展开更多
The atom-economical C-F insertion chemistry is emerged as a promising technology for the synthesis of various fluorinated scaffolds,which have wide applications both in the academic and the industrial com-munities.The...The atom-economical C-F insertion chemistry is emerged as a promising technology for the synthesis of various fluorinated scaffolds,which have wide applications both in the academic and the industrial com-munities.The past three years have witnessed rapid developments in this field.This highlight provides an overview on the evolution according to the fluorinating agents used.展开更多
The potential energy surface and reaction mechanism corresponding to the reaction of ytterbium monocation with fluoromethane, which represents a prototype of the activation of C-F bond in fluorohydrocarbons by bare la...The potential energy surface and reaction mechanism corresponding to the reaction of ytterbium monocation with fluoromethane, which represents a prototype of the activation of C-F bond in fluorohydrocarbons by bare lanthanide cations, have been investigated for the first time by using density functional theory. A direct fluorine abstraction mechanism was revealed, and the related thermochemistry data were determined. The electron-transfer reactivity of the reaction was analyzed using the two-state model, and a strongly avoided crossing behavior on the transition state region was shown. The present results support the reaction mechanism inferred from early experimental data and the related thermochemistry data can provide a guide for further experimental researches.展开更多
The emission changes of fluorescent dyes under the influence of environmental changes or interaction with analytes are the basis for designing ratiometric fluorescent probes and logic gates. However, it is rare that o...The emission changes of fluorescent dyes under the influence of environmental changes or interaction with analytes are the basis for designing ratiometric fluorescent probes and logic gates. However, it is rare that only one external stimulus induces continuous fluorescent color changes in a fluorescent dye.In this paper, we report a cage-like molecule formed by two benzene rings and three imidazolium salts which produces continuous fluorescence wavelength changes when interacted with fluoride ions. Fluoride ions are first bound to the center of the cage under the action of anion-π interaction, and the(C-H)^(+)···F^(–)type ionic hydrogen bonds induce the blue-shift of fluorescence. The subsequent formation of C-F covalent bonds with fluoride ions makes the fluorophore wavelength continue to blue-shift, and finally obtains continuous multiple fluorescence changes caused by a single external stimulus. According to the fluorescence wavelength and intensity, six different fluorescence signal channels can be obtained,which can be encoded as six numbers from 0 to 5. We expect that this reaction process can find applications in quantitative anion recognition and molecular counters.展开更多
基金financial support from the Marine S&T Fund of Shandong Province for Pilot National Laboratory for Marine Science and Technology(Qingdao)(No.2022QNLM030003-2)the National Natural Science Foundation of China(No.21977088)the National Natural Science Foundation of China-Shandong Joint Fund(No.U1906213)。
文摘Ag_(2)CO_(3)-promoted dehydroxymethylative fluorination of aliphatic alcohols has been achieved with Selectfluor as both oxidant and fluorine source.The reaction involvesβ-fragmentation of primary alkoxy radicals,followed by the fluorination of the resulting C-centered radical intermediates.The transformation proceeds under mild reaction conditions and exhibits a broad substrate scope,thus opening up a new entrance to the synthesis of fluorinated constructs includingα-fluoroimides and 1-fluoroalkyl benzoates as well as secondary and tertiary alkyl fluorides like versatile 2-fluoro-2-alkyl 1,3-propandiol derivatives.The divergent functionalization of the obtainedα-fluoroimides enables an efficient access to amine derivatives through C-F bond activation under the action of BF_(3)·OEt_(2).
文摘[目的]探讨鳖甲寡肽I-C-F-6对乙醇诱导的小鼠慢性肝损伤的预防作用,并分析其可能的保护机制。[方法]将90只ICR小鼠随机分为正常对照组、模型组、寡肽低剂量组(0.12 mg/kg)、寡肽高剂量组(0.24 mg/kg)、阳性药组(240.00 mg/kg)。正常对照组和模型组均皮下注射生理盐水(0.12 m L/kg);寡肽低剂量组和寡肽高剂量组分别皮下注射寡肽的生理盐水溶液(0.12 m L/kg);阳性药组灌胃还原型谷胱甘肽生理盐水溶液(0.12 m L/kg),同时除正常对照组外,其余4组给予灌胃40%乙醇(0.12 m L/kg),每日1次,连续16周。16周后,末次给乙醇12 h后处死小鼠采集血液样品和肝组织样品,测定血清谷丙转氨酶(ALT)、谷草转氨酶(AST)和碱性磷酸酶(AKP)的活力,肝组织超氧化物歧化酶(SOD)活力、丙二醛含量(MDA),单胺氧化酶(MAO)的活力,并进行病理组织学检查。[结果]鳖甲寡肽I-C-F-6使灌胃乙醇后小鼠体内ALT、AST、MDA、MAO、AKP的含量显著降低(P<0.05),肝组织匀浆中SOD的活力明显升高(P<0.05),肝脏病理损伤减轻。[结论]鳖甲寡肽I-C-F-6对小鼠慢性酒精性肝损伤具有一定的预防保护作用,其机制可能与抑制脂质过氧化,清除自由基,升高SOD的活力有关。
基金The Tertiary Education Scientific Research Project of Guangzhou Municipal Education Bureau(No.202235305)is gratefully acnowledged for financial support.
文摘The atom-economical C-F insertion chemistry is emerged as a promising technology for the synthesis of various fluorinated scaffolds,which have wide applications both in the academic and the industrial com-munities.The past three years have witnessed rapid developments in this field.This highlight provides an overview on the evolution according to the fluorinating agents used.
基金supported by the National Science Foundation of Shandong Province(No.Z2000B02).
文摘The potential energy surface and reaction mechanism corresponding to the reaction of ytterbium monocation with fluoromethane, which represents a prototype of the activation of C-F bond in fluorohydrocarbons by bare lanthanide cations, have been investigated for the first time by using density functional theory. A direct fluorine abstraction mechanism was revealed, and the related thermochemistry data were determined. The electron-transfer reactivity of the reaction was analyzed using the two-state model, and a strongly avoided crossing behavior on the transition state region was shown. The present results support the reaction mechanism inferred from early experimental data and the related thermochemistry data can provide a guide for further experimental researches.
基金the financial support from the National Natural Science Foundation of China (Nos. 22078314, 21878286, 21908216)Dalian Institute of Chemical Physics (Nos. DICPI201938, DICPZZBS201805)。
文摘The emission changes of fluorescent dyes under the influence of environmental changes or interaction with analytes are the basis for designing ratiometric fluorescent probes and logic gates. However, it is rare that only one external stimulus induces continuous fluorescent color changes in a fluorescent dye.In this paper, we report a cage-like molecule formed by two benzene rings and three imidazolium salts which produces continuous fluorescence wavelength changes when interacted with fluoride ions. Fluoride ions are first bound to the center of the cage under the action of anion-π interaction, and the(C-H)^(+)···F^(–)type ionic hydrogen bonds induce the blue-shift of fluorescence. The subsequent formation of C-F covalent bonds with fluoride ions makes the fluorophore wavelength continue to blue-shift, and finally obtains continuous multiple fluorescence changes caused by a single external stimulus. According to the fluorescence wavelength and intensity, six different fluorescence signal channels can be obtained,which can be encoded as six numbers from 0 to 5. We expect that this reaction process can find applications in quantitative anion recognition and molecular counters.
