An exceptional HF transfer reaction by C–F bond activation of fluoropentane and a subsequent hydrofluorination of alkynes at room temperature is reported. An amorphous Lewis-acidic Zr chlorofluoride serves as heterogeneous catalyst, which is characterised by an eightfold coordination environment at Zr including chlorine atoms. The studies are seminal in establishing sustainable fluorine chemistry.
sol–gel reaction with anhydrous isopropanol/HF solution was investigated. The subsequent post-fluorination step was optimised in its temperature ramp and confirmed the necessity of a fluorination of the generated xerogels to obtain catalytic activity. The process is discussed in the context of the analysis of the materials using Brunauer–Emmett–Teller analysis (BET), powder X-ray diffraction (XRD), infrared
通过氟解溶胶-凝胶路线开发了一种在室温弗里德-克来福特和脱氟化氢反应中具有活性的ZrF 4催化剂的路线,随后是使用CHClF 2流的后氟化步骤。研究了不同Zr( IV )前驱体在与无水异丙醇/HF溶液的溶胶-凝胶反应中的行为。随后的氟化后步骤在温度梯度方面进行了优化,并证实了对所生成的干凝胶进行氟化以获得催化活性的必要性。在使用 Brunauer-Emmett-Teller 分析 (BET)、粉末 X 射线衍射 (XRD)、红外光谱 (IR)、热重分析 (TGA) 和差示扫描量热法 (DSC) 进行材料分析的背景下讨论了该过程)。通过扩展X射线吸收精细结构光谱(EXAFS)阐明了非晶催化剂的局部结构。
Dehydrofluorination reactions at Lewis acidic ACF in the presence of HSnBu3
作者:Xinzi Pan、Maria Talavera、Thomas Braun
DOI:10.1016/j.jfluchem.2022.110046
日期:2022.11
Dehydrofluorination reactions of fluoroalkanes were catalyzed by the highly Lewis acidic nanoscopic aluminum chlorofluoride (ACF, AlClxF3-x, x ≈ 0.05–0.3) in the presence of HSnBu3 as hydrogen source. Mechanistic studies suggest an initial interaction of ACF with the tin hydride instead of the fluoroalkane. MAS NMR studies provided information on the interaction of HSnBu3 with the ACF surface as well
在 HSnBu 3作为氢源的情况下,氟代烷烃的脱氟化氢反应由高路易斯酸性纳米级氯氟化铝 (ACF, AlCl x F 3- x , x ≈ 0.05–0.3) 催化。机理研究表明 ACF 与氢化锡而不是氟烷的初始相互作用。MAS NMR 研究提供了有关 HSnBu 3与 ACF 表面的相互作用以及 ACF 在没有添加剂的情况下对氟代烷烃进行 C-F 键活化的能力的信息。