Platinum-Catalyzed, Terminal-Selective C(sp(3))-H Oxidation of Aliphatic Amines.
Platinum-Catalyzed, Terminal-Selective C(sp(3))-H Oxidation of Aliphatic Amines.
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DOI：
10.1021/jacs.5b09099
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发表时间：
2015-10-14
影响因子：
15
通讯作者：
Sanford MS
中科院分区：
文献类型：
--
作者：
Lee M;Sanford MS
本文介绍了不需要导向基团的Pt催化的脂肪胺的末端选择性C（sp3）-H氧化。CuCl 2被用作化学计量的氧化剂，并且反应在低至1摩尔%的Pt负载量下以高产率进行。这些转化在硫酸存在下进行，硫酸与胺底物原位反应形成铵盐。我们提出，质子化的胺至少有三个重要的作用：（i）它使基板可溶于水性反应介质中;（ii）它限制了结合的胺氮铂或铜;和（ii）它电子钝化的C-H键的氮中心附近。我们证明，这种策略是有效的终端选择性C（sp3）-H氧化的各种伯，仲和叔胺。
This paper describes the terminal-selective Pt-catalyzed C(sp3)–H oxidation of aliphatic amines without the requirement for directing groups. CuCl2 is employed as a stoichiometric oxidant, and the reactions proceed in high yield at Pt loadings as low as 1 mol %. These transformations are conducted in the presence of sulfuric acid, which reacts with the amine substrates in situ to form ammonium salts. We propose that protonation of the amine serves at least three important roles: (i) it renders the substrates soluble in the aqueous reaction medium; (ii) it limits binding of the amine nitrogen to Pt or Cu; and (ii) it electronically deactivates the C–H bonds proximal to the nitrogen center. We demonstrate that this strategy is effective for the terminal-selective C(sp3)–H oxidation of a variety of primary, secondary and tertiary amines.