Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA.
Nat Chem. 2018 Feb;10(2):200-204. doi: 10.1038/nchem.2873. Epub 2017 Oct 16.
The development of sustainable oxidation chemistry demands strategies to harness O as a terminal oxidant. Oxidase catalysis, in which O serves as a chemical oxidant without necessitating incorporation of oxygen into reaction products, would allow diverse substrate functionalization chemistry to be coupled to O reduction. Direct O utilization suffers from intrinsic challenges imposed by the triplet ground state of O and the disparate electron inventories of four-electron O reduction and two-electron substrate oxidation. Here, we generate hypervalent iodine reagents-a broadly useful class of selective two-electron oxidants-from O. This is achieved by intercepting reactive intermediates of aldehyde autoxidation to aerobically generate hypervalent iodine reagents for a broad array of substrate oxidation reactions. The use of aryl iodides as mediators of aerobic oxidation underpins an oxidase catalysis platform that couples substrate oxidation directly to O reduction. We anticipate that aerobically generated hypervalent iodine reagents will expand the scope of aerobic oxidation chemistry in chemical synthesis.
可持续氧化化学的发展需要利用 O 作为终端氧化剂的策略。氧化酶催化，其中 O 作为化学氧化剂，而不需要将氧掺入反应产物中，将允许将各种底物功能化化学与 O 还原偶联。直接利用 O 会受到 O 的三重基态和四电子 O 还原与两电子底物氧化之间电子库存差异所带来的固有挑战的限制。在这里，我们从 O 中生成高价碘试剂 - 一类广泛使用的选择性两电子氧化剂。这是通过拦截醛自氧化的反应中间体来实现的，以有氧方式生成高价碘试剂，用于广泛的底物氧化反应。芳基碘化物作为有氧氧化的介体的使用为氧化酶催化平台奠定了基础，该平台将底物氧化直接偶联到 O 还原。我们预计，有氧生成的高价碘试剂将扩大有氧氧化化学在化学合成中的范围。
