Universität Regensburg, Fakultät für Chemie und Pharmazie, 93040, Regensburg, Germany.
Angew Chem Int Ed Engl. 2017 Jul 10;56(29):8544-8549. doi: 10.1002/anie.201703004. Epub 2017 May 24.
Photosynthetic organisms exploit antenna chromophores to absorb light and transfer excitation energy to the reaction center where redox reactions occur. In contrast, in visible-light chemical photoredox catalysis, a single species (i.e., the photoredox catalyst) absorbs light and performs the redox chemistry. Mimicking the energy flow of the biological model, we report a two-center photoredox catalytic approach in which the tasks of light energy collection and electron transfer (i.e., redox reactions) are assigned to two different molecules. Ru(bpy) Cl absorbs the visible light and transfers the energy to polycyclic aromatic hydrocarbons that enable the redox reactions. This operationally simple sensitization-initiated electron transfer enables the use of arenes that do not absorb visible light, such as anthracene or pyrene, for photoredox applications. We demonstrate the merits of this approach by the reductive activation of chemical bonds with high reduction potentials for carbon-carbon and carbon-heteroatom bond formations.
光合生物利用天线发色团吸收光，并将激发能转移到反应中心，在那里发生氧化还原反应。相比之下，在可见光化学光氧化还原催化中，单个物种（即光氧化还原催化剂）吸收光并进行氧化还原化学。为了模拟生物模型的能量流动，我们报告了一种双中心光氧化还原催化方法，其中光能收集和电子转移（即氧化还原反应）的任务分配给两个不同的分子。Ru(bpy)Cl 吸收可见光，并将能量传递给多环芳烃，从而实现氧化还原反应。这种操作简单的敏化引发的电子转移使不吸收可见光的芳烃（如蒽或芘）能够用于光氧化还原应用。我们通过高还原电位的化学键的还原活化来证明这种方法的优点，这些化学键用于形成碳-碳和碳-杂原子键。
