A Structurally Characterized Nonheme Cobalt-Hydroperoxo Complex Derived from Its Superoxo Intermediate via Hydrogen Atom Abstraction

作者：Wang, Chun Chieh; Chang, Hao Ching; Lai, Yei Chen; Fang, Huayi; Li, Chieh Chin; Hsu, Hung Kai; Li, Zong Yan; Lin, Tien Sung; Kuo, Ting Shen; Neese, Frank; Ye, Shengfa^*; Chiang, Yun Wei^*; Tsai, Ming Li^*; Liaw, Wen Feng^*; Lee, Way Zen^*

来源：Journal of the American Chemical Society, 2016, 138(43): 14186-14189.

DOI：10.1021/jacs.6b08642

Bubbling O-2 into a THE solution of CoH(BDPP) (1) at -90 degrees C generates an O-2 adduct, Co(BDPP)(O-2) (3). The resonance Raman and EPR investigations reveal that 3 contains a low spin cobalt(III) ion bound to a superoxo ligand. Significantly, at -90 degrees C, 3 can react with 2,2,6,6-tetramethyl-1-hydroxypiperidine (TEMPOH) to form a structurally characterized cobalt(III)-hydroperoxo complex, Co-III(BDPP)(OOH) (4) and TEMPO center dot. Our findings show that cobalt(III)-superoxo species are capable of performing, hydrogen atom abstraction processes. Such a stepwise O-2-activating process helps to rationalize cobalt-catalyzed aerobic oxidations and sheds light on the possible mechanism of action for Co-bleomycin.

• 出版日期2016-11-2
• 单位清华大学; 中山大学