Although many electrophilic trifluoromethylating agents have been reported to date, practically useful reagents have yet to be developed. S-(Trifluoromethyl)dibenzothiophenium salts, known as Umemoto’s reagents, have two significant drawbacks that have hampered their practical application: (1) synthesis involving many steps and (2) the formation of large amounts of dibenzothiophene as waste after trifluoromethylation. Our idea to substitute fluorine at specific positions on the dibenzothiophenium rings has resulted in massive improvements in the synthesis, properties, reactivity, and applications of these compounds. On the basis of this idea, 2,8-difluoro- and 2,3,7,8-tetrafluoro-S-(trifluoromethyl)dibenzothiophenium triflates and other salts were developed as powerful, thermally stable, one-pot-preparable, and recyclable reagents for the trifluoromethylation of various types of nucleophilic substrates, such as carbanions, (hetero)aromatics, alkenes, alkynes, thiols, sulfinates, and phosphines. This one-pot and recycled production tremendously decreases the chemical and environmental costs of this process. Because of their higher reactivity and thermal stability, these new reagents may have wider applications than Umemoto’s reagents. Therefore, these new versions of Umemoto’s reagents could be widely used as the first practically useful electrophilic trifluoromethylating agents for the production of many types of trifluoromethyl-containing compounds in academic and industrial applications.

中文翻译：

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功能强大，热稳定，可一次性制备且可回收的亲电子三氟甲基化剂：2,8-二氟-和2,3,7,8-四氟-S-（三氟甲基）二苯并噻吩鎓盐

尽管迄今为止已报道了许多亲电子三氟甲基化剂，但尚未开发出实用的试剂。S-（三氟甲基）二苯并噻吩盐，被称为梅本试剂，具有两个严重的缺点，阻碍了它们的实际应用：（1）合成涉及许多步骤，（2）三氟甲基化后形成大量的二苯并噻吩作为废物。我们在二苯并噻吩环上特定位置取代氟的想法导致这些化合物的合成，性质，反应性和应用得到了极大的改善。根据这个想法，2,8-二氟-和2,3,7,8-四氟-S-（三氟甲基）二苯并噻吩三氟甲磺酸盐和其他盐被开发为功能强大，热稳定，可一锅制备且可回收的试剂，用于各种类型的亲核底物的三氟甲基化，例如碳负离子，（杂）芳族化合物，烯烃，炔烃，硫醇，亚磺酸盐和膦。这种一锅又回收的生产方式极大地降低了该过程的化学和环境成本。由于它们具有较高的反应性和热稳定性，因此这些新试剂可能比梅本试剂具有更广泛的应用。因此，这些新版本的梅本试剂可被广泛用作在学术和工业应用中生产许多类型的含三氟甲基化合物的第一种实际有用的亲电子三氟甲基化试剂。