Diversion of Catalytic C-N Bond Formation to Catalytic Oxidation of NH3 through Modification of the Hydrogen Atom Abstractor
Diversion of Catalytic C-N Bond Formation to Catalytic Oxidation of NH3 through Modification of the Hydrogen Atom Abstractor
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DOI：
10.1021/jacs.9b13706
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发表时间：
2020-02-19
影响因子：
15
通讯作者：
Bullock, R. Morris
中科院分区：
文献类型：
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作者：
Dunn, Peter L.;Johnson, Samantha I.;Bullock, R. Morris
我们报道了(TMP)Ru(NH3)(2)(TMP=四甲基膦)是氨氧化制氮气的分子催化剂。芳氧基，三叔丁基苯氧基(ArO中心点)，从(TMP)Ru(NH3)(2)的结合氨配体中提取H原子，导致发现一个新的催化C-N偶联到ArO中心点的对位以形成4-amino-2，4，6-tri-tert-butylcyclohexa2，5-dien-1-one.将芳氧基修饰为2，6-二叔丁基-4-三叔丁基-4-三苯氧基，在对位上含有一个三苯基，防止了C-N偶联，并将反应转移到NH3的催化氧化生成N-2。我们在22摄氏度下实现了NH3氧化的125+/-5个转化率，这是迄今为止报道的分子催化剂的最高转化率(吨)。
We report that (TMP)Ru(NH3)(2) (TMP = tetramesitylporphryin) is a molecular catalyst for oxidation of ammonia to dinitrogen. An aryloxy radical, tri-tent-butylphenoxyl (ArO center dot), abstracts H atoms from a bound ammonia ligand of (TMP)Ru(NH3)(2), leading to the discovery of a new catalytic C-N coupling to the para position of ArO center dot to form 4-amino-2,4,6-tri-tert-butylcyclohexa2,5-dien-1-one. Modification of the aryloxy radical to 2,6-di-tert-butyl-4-tritylphenoxyl radical, which contains a trityl group at the para position, prevents C-N coupling and diverts the reaction to catalytic oxidation of NH3 to give N-2. We achieved 125 +/- 5 turnovers at 22 degrees C for oxidation of NH3, the highest turnover number (TON) reported to date for a molecular catalyst.