A mechanistic investigation of the photoinduced, copper-mediated cross-coupling of an aryl thiol with an aryl halide.
A mechanistic investigation of the photoinduced, copper-mediated cross-coupling of an aryl thiol with an aryl halide.
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DOI：
10.1039/c5sc04709a
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发表时间：
2016-07-01
期刊：
影响因子：
8.4
通讯作者：
Peters JC
中科院分区：
文献类型：
--
作者：
Johnson MW;Hannoun KI;Tan Y;Fu GC;Peters JC
光诱导的铜催化的交叉偶联可以提供用于产生C-X（X = C、N、O、S等）的热（非光诱导）方法的补充方法。债券在这份报告中，我们描述了第一个详细的机制调查的过程中，我们已经开发，具体来说，（化学计量）耦合的硫醇铜与芳基碘。特别是，我们专注于离散[CuI（SAr）2]−络合物（Ar = 2，6-二甲基苯基）的化学，应用一系列技术，包括ESI-MS，循环伏安法，瞬态发光光谱，光谱学，DFT计算，Stern-Volmer分析，EPR光谱学，辐射测量和反应性研究。现有的数据与光激发的[CuI（SAr）2]−* 作为芳基碘的电子供体提供芳基自由基的途径的可行性一致，然后芳基自由基与新生成的硫醇铜（ii）在笼中反应，以非链过程提供交叉偶联产物。机制研究建立了铜介导的光诱导C-S交叉偶联途径的可行性，涉及单电子转移和笼内自由基重组。
Photoinduced, copper-catalyzed cross-coupling can offer a complementary approach to thermal (non-photoinduced) methods for generating C–X (X = C, N, O, S, etc.) bonds. In this report, we describe the first detailed mechanistic investigation of one of the processes that we have developed, specifically, the (stoichiometric) coupling of a copper–thiolate with an aryl iodide. In particular, we focus on the chemistry of a discrete [CuI(SAr)2]− complex (Ar = 2,6-dimethylphenyl), applying a range of techniques, including ESI-MS, cyclic voltammetry, transient luminescence spectroscopy, optical spectroscopy, DFT calculations, Stern–Volmer analysis, EPR spectroscopy, actinometry, and reactivity studies. The available data are consistent with the viability of a pathway in which photoexcited [CuI(SAr)2]−* serves as an electron donor to an aryl iodide to afford an aryl radical, which then reacts in cage with the newly generated copper(ii)–thiolate to furnish the cross-coupling product in a non-chain process. A mechanistic study establishes the viability of a copper-mediated pathway for photoinduced C–S cross-coupling involving single electron transfer and in-cage radical recombination.