Synthesis and applications of S-(trifluoromethyl)-2,8-bis(trifluoromethoxy)dibenzothiophenium triflate (Umemoto reagent IV).
Synthesis and applications of S-(trifluoromethyl)-2,8-bis(trifluoromethoxy)dibenzothiophenium triflate (Umemoto reagent IV).
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DOI：
10.1016/j.jfluchem.2022.110015
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发表时间：
2022-07
影响因子：
1.9
通讯作者：
Sagar R. Mudshinge;G. Hammond;T. Umemoto
中科院分区：
文献类型：
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作者：
Sagar R. Mudshinge;G. Hammond;T. Umemoto
开发了一种新的、功能强大且易于操作的亲电三氟甲基化试剂S-（三氟甲基）-2，8-双（三氟甲氧基）二苯并噻吩三氟甲磺酸盐（Umemoto试剂IV）。由于三氟甲氧基的特殊电子效应，由易得的3，3 '-二（三氟甲氧基）联苯通过一锅法容易地合成了梅本试剂IV。结果表明，Umemoto试剂IV比Umemoto试剂II更有效，能更有效地对多种亲核底物进行三氟甲基化。此外，Umemoto试剂IV成功地用于制备三氟甲基九氟丁磺酸酯，一种有用的三氟甲基化剂。实现了用三氟甲磺酸酐将2，8-双（三氟甲氧基）二苯并噻吩直接转化为梅本试剂IV，尽管产率较低。
A new, powerful, and easy-to-handle electrophilic trifluoromethylating agent,S-(trifluoromethyl)-2,8-bis(trifluoromethoxy)dibenzothiophenium triflate (Umemoto reagent IV), was developed. Due to the extraordinary electronic effect of trifluoromethoxy group, Umemoto reagent IV was easily synthesized by a one-pot method from readily available 3,3’-bis(trifluoromethoxy)biphenyl. It was shown that Umemoto reagent IV was more powerful than Umemoto reagent II and could trifluoromethylate many kinds of nucleophilic substrates more effectively. In addition, Umemoto reagent IV was successfully utilized for the preparation of trifluoromethyl nonaflate, a useful trifluoromethoxylating agent. The direct conversion of 2,8-bis(trifluoromethoxy)dibenzothiophene to Umemoto reagent IV with triflic anhydride was achieved, albeit in low yield.