Intra- and Intermolecular C-H Activation by Bis(phenolate)pyridineiridium(III) Complexes
Intra- and Intermolecular C-H Activation by Bis(phenolate)pyridineiridium(III) Complexes
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DOI：
10.1021/om201069k
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发表时间：
2011-12-26
期刊：
影响因子：
2.8
通讯作者：
Labinger, Jay A.
中科院分区：
文献类型：
--
作者：
Fu, Ross;Bercaw, John E.;Labinger, Jay A.
双(酚盐)吡啶钳配体（以下缩写为ONO）已被用来支持多种氧化态I、III和IV的铱配合物。配合物 (ONO)IrL2Me (L = PPh3, PEt3) 与 12 反应，裂解 Ir-C 键并释放 MeI，显然是通过从电子转移开始的机制生成中间体 Ir(IV) 配合物，在 L = PEt3 的情况下可以分离并表征该配合物。 PPh3 络合物在 65 摄氏度的苯中转化为相应的苯基络合物，同时损失甲烷，随后转化为 PPh3 配体金属化产生的物质。标记和动力学研究表明，PPh3 是 C-H 活化的初始位点，尽管第一个观察到的产物是分子间苯活化产生的产物。还观察到乙腈的 C-H 活化。
A bis(phenolate)pyridine pincer ligand (henceforth abbreviated as ONO) has been employed to support a variety of iridium complexes in oxidation states I, III, and IV. Complexes (ONO)IrL2Me (L = PPh3, PEt3) react with 12 to cleave the Ir-C bond and liberate MeI, apparently via a mechanism beginning with electron transfer to generate an intermediate Ir(IV) complex, which can be isolated and characterized for the case L = PEt3. The PPh3 complex is transformed in benzene at 65 degrees C to the corresponding phenyl complex, with loss of methane, and subsequently to a species resulting from metalation of a PPh3 ligand. Labeling and kinetics studies indicate that PPh3 is the initial site of C-H activation, even though the first observed product is that resulting from intermolecular benzene activation. C-H activation of acetonitrile has also been observed.