Kim Yeong-Eun, Lee Yunho
Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon, 34141, Republic of Korea.
Angew Chem Int Ed Engl. 2018 Oct 22;57(43):14159-14163. doi: 10.1002/anie.201809122. Epub 2018 Oct 8.
The carbonylation of a nickel(II) anilido species 2 led to the formation of a dinickel(0)-CO complex (P P-PP ){Ni(CO)} 3 with a P-P bond along with isocyanate generation. In this reaction, the central phosphide moiety of an anionic PPP ligand (PPP = P[2-P Pr C H ] ) acts as a single-electron donor to form a P radical. Alternatively, 3 can be synthesized from the reduction of (PPP)NiCl (1) in the presence of CO; thus, the reaction proceeds by radical coupling of a P-Ni -CO species. The reverse reaction occurred to generate 1 when 3 was treated with AgCl. Since the P-P bond is light-sensitive, its homolysis is possible and was explored by EPR spectroscopy and DFT analysis. Finally, various bond-activation reactions of 3 occurred under visible-light conditions, thus indicating that a P-P bond can act as an active reaction site.
镍（II）苯胺基物种2的羰基化反应生成了具有P-P键的二镍（0）-CO配合物（P P-PP ）{Ni(CO)} 3并伴有异氰酸酯的生成。在该反应中，阴离子型PPP配体（PPP = P[2-P Pr C H ] ）的中心磷化物部分作为单电子供体形成一个P自由基。另外，3可以在CO存在下通过（PPP）NiCl（1）的还原反应合成；因此，该反应通过P-Ni -CO物种的自由基偶联进行。当3与AgCl反应时会发生逆反应生成1。由于P-P键对光敏感，其均裂是可能的，并通过电子顺磁共振光谱和密度泛函理论分析进行了探究。最后，3在可见光条件下发生了各种键活化反应，从而表明P-P键可以作为一个活性反应位点。
