Oxidative Aliphatic C-H Fluorination with Fluoride Ion Catalyzed by a Manganese Porphyrin
Oxidative Aliphatic C-H Fluorination with Fluoride Ion Catalyzed by a Manganese Porphyrin
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DOI：
10.1126/science.1222327
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发表时间：
2012-09-14
期刊：
影响因子：
56.9
通讯作者：
Groves, John T.
中科院分区：
文献类型：
--
作者：
Liu, Wei;Huang, Xiongyi;Groves, John T.
尽管氟化有机化合物在药物开发中的重要性日益增加，但没有使用方便处理的氟化物盐来取代脂肪族C-H键的直接方案。我们发现，锰卟啉配合物在温和条件下催化氟离子取代烷基，并与碘酰苯化学计量氧化反应相结合。简单的烷烃，萜类化合物，甚至类固醇选择性氟化，否则难以接近的网站在50至60%的收率。萘烷主要在C2和C3亚甲基位置氟化。乙酸冰片酯被转化为外-5-氟-乙酸冰片酯，并且5 α-雄甾烷-17-酮在A环上被选择性氟化。机理分析表明，区域选择性C-H键裂解是直接由氧锰（V）催化中间体，然后通过一个不寻常的锰（IV）的氟化物，已被分离和结构特征的F交付。
Despite the growing importance of fluorinated organic compounds in drug development, there are no direct protocols for the fluorination of aliphatic C-H bonds using conveniently handled fluoride salts. We have discovered that a manganese porphyrin complex catalyzes alkyl fluorination by fluoride ion under mild conditions in conjunction with stoichiometric oxidation by iodosylbenzene. Simple alkanes, terpenoids, and even steroids were selectively fluorinated at otherwise inaccessible sites in 50 to 60% yield. Decalin was fluorinated predominantly at the C2 and C3 methylene positions. Bornyl acetate was converted to exo-5-fluoro-bornyl acetate, and 5a-androstan-17-one was fluorinated selectively in the A ring. Mechanistic analysis suggests that the regioselectivity for C-H bond cleavage is directed by an oxomanganese(V) catalytic intermediate followed by F delivery via an unusual manganese(IV) fluoride that has been isolated and structurally characterized.