Chemistry Department, New York University, 100 Washington Square E., New York, NY, 10003, USA.
Angew Chem Int Ed Engl. 2016 Jun 20;55(26):7534-8. doi: 10.1002/anie.201602566. Epub 2016 May 4.
Natural products containing N-N bonds exhibit important biological activity. Current methods for constructing N-N bonds have limited scope. An advanced understanding of the fundamental N-N bond formation/cleavage processes occurring at the transition-metal center would facilitate the development of catalytic reactions. Herein we present an N-N bond-forming reductive elimination, which proceeds via a mixed-valent Ni(II) -Ni(III) intermediate with a Ni-Ni bond order of zero. The discrete Ni(II) -Ni(III) oxidation states contrast with the cationic dimeric Ni analogue, in which both Ni centers are equivalent with an oxidation state of 2.5. The electronic structures of these mixed-valent complexes have implications for the fundamental understanding of metal-metal bonding interactions.
含 N-N 键的天然产物表现出重要的生物活性。目前构建 N-N 键的方法具有有限的范围。对过渡金属中心发生的基本 N-N 键形成/断裂过程的深入了解将有助于催化反应的发展。在此，我们提出了一种通过混合价 Ni(II)-Ni(III) 中间体进行的 N-N 键形成的还原消除反应，其中 Ni-Ni 键序为零。离散的 Ni(II)-Ni(III) 氧化态与阳离子二聚 Ni 类似物形成对比，其中两个 Ni 中心具有 2.5 的等效氧化态。这些混合价配合物的电子结构对金属-金属键相互作用的基本理解具有重要意义。
