Photoredox catalysis, especially in combination with transition metal catalysis, can produce redox states of transition metal catalysts to facilitate challenging bond formations that are not readily accessible in conventional redox catalysis. For arene functionalization, metallophotoredox catalysis has successfully made use of the same leaving groups as those valuable in conventional cross-coupling catalysis, such as bromide. Yet the redox potentials of common photoredox catalysts are not sufficient to reduce most aryl bromides, so synthetically useful aryl radicals are often not directly available. Therefore, the development of a distinct leaving group more appropriately matched in redox potential could enable new reactivity manifolds for metallophotoredox catalysis, especially if arylcopper(III) complexes are accessible, from which the most challenging bond-forming reactions can occur. Here we show the conceptual advantages of aryl thianthrenium salts for metallophotoredox catalysis, and their utility in site-selective late-stage aromatic fluorination.

中文翻译：

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用芳基sulf盐进行光氧化还原催化可实现位点选择性的后期氟化。

光氧化还原催化，特别是与过渡金属催化结合，可以产生过渡金属催化剂的氧化还原态，以促进在传统氧化还原催化中不易获得的具有挑战性的键形成。对于芳烃官能化，金属光氧化还原催化已成功利用与在常规交叉偶联催化中有价值的那些离去基团相同的离去基团，例如溴化物。然而，普通的光氧化还原催化剂的氧化还原电势不足以还原大多数芳基溴化物，因此合成上有用的芳基常常不能直接获得。因此，在氧化还原电势上更合适地匹配一个独特的离去基团的开发，可以为金属光氧化还原催化提供新的反应性流形，特别是如果芳基铜（III）配合物可及的话，从中可以发生最具挑战性的成键反应。在这里，我们显示了芳基ian盐在金属光氧化还原催化方面的概念优势，以及它们在定点选择性后期芳族氟化反应中的效用。