Neu Heather M, Jung Jieun, Baglia Regina A, Siegler Maxime A, Ohkubo Kei, Fukuzumi Shunichi, Goldberg David P
†Department of Chemistry, The Johns Hopkins University, Baltimore, Maryland 21218, United States.
‡Department of Material and Life Science, Graduate School of Engineering, Osaka University, ALCA, Japan Science and Technology Agency, Suita, Osaka 565-0871, Japan.
J Am Chem Soc. 2015 Apr 15;137(14):4614-7. doi: 10.1021/jacs.5b00816. Epub 2015 Apr 3.
The visible light-driven, catalytic aerobic oxidation of benzylic C-H bonds was mediated by a Mn(III) corrolazine complex. To achieve catalytic turnovers, a strict selective requirement for the addition of protons was established. The resting state of the catalyst was unambiguously characterized by X-ray diffraction as Mn(III)(H2O)(TBP8Cz(H)), in which a single, remote site on the ligand is protonated. If two remote sites are protonated, however, reactivity with O2 is shut down. Spectroscopic methods revealed that the related Mn(V)(O) complex is also protonated at the same remote site at -60 °C, but undergoes valence tautomerization upon warming.
苄基碳氢键的可见光驱动催化需氧氧化反应由一种锰（III）咕啉配合物介导。为实现催化周转，对质子添加建立了严格的选择性要求。通过X射线衍射明确表征出催化剂的静止态为Mn(III)(H2O)(TBP8Cz(H))，其中配体上的一个单一远程位点被质子化。然而，如果两个远程位点被质子化，与O2的反应性就会关闭。光谱方法表明，相关的Mn(V)(O)配合物在-60°C时在同一远程位点也被质子化，但升温时会发生价互变异构。
