Synthesis ( IF 2.2 ) Pub Date : 2018-06-26 , DOI: 10.1055/s-0037-1609759 Hiromichi Egami 1 , Yoshitaka Hamashima 1 , Yuta Ito 1 , Takafumi Ide , Shuya Masuda 1
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Published as part of the Special Topic Modern Radical Methods and their Strategic Applications in Synthesis
Abstract
The trifluoromethylation of various aromatic compounds with Umemoto reagent II (2,8-difluoro-5-(trifluoromethyl)-5H-dibenzo[b,d]thiophen-5-ium triflate) proceeded in moderate to good yields under simple photo-irradiation conditions without any catalyst, additive, or activator. UV-Vis and NMR spectral analyses indicated that pre-formation of an electron donor-acceptor complex between the trifluoromethylating reagent and the substrate, as proposed in previous studies, is not essential for generation of the trifluoromethyl radical. Instead, the radical appears to be formed by simple photo-activation of the Umemoto reagent.
The trifluoromethylation of various aromatic compounds with Umemoto reagent II (2,8-difluoro-5-(trifluoromethyl)-5H-dibenzo[b,d]thiophen-5-ium triflate) proceeded in moderate to good yields under simple photo-irradiation conditions without any catalyst, additive, or activator. UV-Vis and NMR spectral analyses indicated that pre-formation of an electron donor-acceptor complex between the trifluoromethylating reagent and the substrate, as proposed in previous studies, is not essential for generation of the trifluoromethyl radical. Instead, the radical appears to be formed by simple photo-activation of the Umemoto reagent.
中文翻译：
芳香环的简单光诱导三氟甲基化
作为特别主题“现代自由基方法及其在合成中的战略应用”的一部分发布
抽象的
用梅本试剂II（2,8-二氟-5-（三氟甲基）-5 H-二苯并[ b，d ]噻吩-5-三氟甲磺酸盐）进行的各种芳族化合物的三氟甲基化在简单的光照射下以中等至良好的产率进行没有任何催化剂，添加剂或活化剂的条件。UV-Vis和NMR光谱分析表明，如先前研究中所述，在三氟甲基化试剂和底物之间预先形成电子供体-受体配合物对于生成三氟甲基自由基不是必需的。相反，自由基似乎是通过梅本试剂的简单光活化而形成的。
用梅本试剂II（2,8-二氟-5-（三氟甲基）-5 H-二苯并[ b，d ]噻吩-5-三氟甲磺酸盐）进行的各种芳族化合物的三氟甲基化在简单的光照射下以中等至良好的产率进行没有任何催化剂，添加剂或活化剂的条件。UV-Vis和NMR光谱分析表明，如先前研究中所述，在三氟甲基化试剂和底物之间预先形成电子供体-受体配合物对于生成三氟甲基自由基不是必需的。相反，自由基似乎是通过梅本试剂的简单光活化而形成的。
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