The Role of lodanyl Radicals as Critical Chain Carriers in Aerobic Hypervalent Iodine Chemistry
The Role of lodanyl Radicals as Critical Chain Carriers in Aerobic Hypervalent Iodine Chemistry
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DOI：
10.1016/j.chempr.2019.06.006
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发表时间：
2019-09-12
期刊：
影响因子：
23.5
通讯作者：
Powers, David C.
中科院分区：
文献类型：
--
作者：
Hyun, Sung-Min;Yuan, Mingbin;Powers, David C.
选择性利用O-2仍然是合成化学中的一个重大挑战。生物小分子氧化反应通常利用需氧产生的高价催化剂中间体来实现底物氧化。用于需氧氧化催化的可用合成方法在很大程度上限于通过低价催化剂中间体（即，需氧生成的Pd（II）中间体）。出于对有氧氧化催化新化学平台的需求，我们最近开发了有氧高价碘化学。在这里，我们报告说，在对比的有机碘化物的氧化的典型的两个电子的氧化机制，发达的有氧高价碘化学收益通过自由基链机制引发的有氧产生的乙酰氧基自由基的芳基碘化物。尽管有自由基链机制，但需氧高价碘化学显示出与传统末端氧化剂（如过酸）相似的底物耐受性。我们预计，这些见解将通过高价碘中间体实现新的可持续氧化化学。
Selective O-2 utilization remains a substantial challenge in synthetic chemistry. Biological small-molecule oxidation reactions often utilize aerobically generated high-valent catalyst intermediates to effect substrate oxidation. Available synthetic methods for aerobic oxidation catalysis are largely limited to substrate functionalization chemistry by low-valent catalyst intermediates (i.e., aerobically generated Pd(II) intermediates). Motivated by the need for new chemical platforms for aerobic oxidation catalysis, we recently developed aerobic hypervalent iodine chemistry. Here, we report that in contrast to the canonical two-electron oxidation mechanisms for the oxidation of organoiodides, the developed aerobic hypervalent iodine chemistry proceeds via a radical chain mechanism initiated by the addition of aerobically generated acetoxy radicals to aryl iodides. Despite the radical chain mechanism, aerobic hypervalent iodine chemistry displays substrate tolerance similar to that observed with traditional terminal oxidants, such as peracids. We anticipate that these insights will enable new sustainable oxidation chemistry via hypervalent iodine intermediates.