摘要/Abstract

报道了一种负载钯纳米颗粒催化2-苯基吡啶与芳磺酰氯的邻位导向磺化反应.对反应前后的负载钯纳米颗粒催化剂进行X射线光电子能谱（XPS）分析，发现反应后钯完全被氧化.结果证明钯催化的邻位导向磺化反应是经由Pd^Ⅱ/IV催化循环，而不是Pd^0/Ⅱ催化循环.热过滤实验及其催化剂的表征进一步证明了这个假设，提供了在邻位导向磺化反应中确定钯价态变化的直接方法.
关键词: C—H功能化, 钯纳米颗粒催化剂, 磺化, XPS分析
Catalyzed by supported palladium nanoparticles, an ortho-directed sulfonylation reaction between 2-phenylpyri-dine and arylsulfonyl chlorides has been developed. The full oxidation-state change of palladium was detected in the X-ray photoelectron spectroscopy (XPS) analysis of the supported palladium nanoparticles catalyst before and after reaction, which confirmed that Pd-catalyzed ortho-directed sulfonylation reaction was performed via a Pd^Ⅱ/IV catalytic cycle instead of Pd^0/Ⅱ. The hot filtration test and other tests of catalysts further confirmed the hypothesis. This report afforded the most straightforward approach to confirm the variation of valence of palladium in ortho-directed sulfonylation reaction.
Key words: C-H functionalization, X-ray photoelectron spectroscopy (XPS) analysis, palladium nanoparticles catalyst, sulfonylation


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