Promoting a non-heme manganese complex catalyzed oxygen transfer reaction by both lewis acid and Bronsted acid: Similarities and distinctions

作者：Choe, Cholho; Lv, Zhanao; Wu, Yunfeng; Chen, Zhuqi^*; Sun, Tingting; Wang, Haibin; Li, Guangxing^*; Yin, Guochuan^*

来源：Molecular Catalysis, 2017, 438: 230-238.

DOI：10.1016/j.mcat.2017.05.030

• Non-heme manganese complexes
• Non-redox metal ions
• Bronsted acid
• Olefin epoxidation
• Synergetic catalysis

This work demonstrates that certain Lewis and Bronsted acids can sharply improve the oxygen transfer efficiency of a manganese(II) catalyst bearing non-heme ligand. In the absence of Lewis and Bronsted acids, oxidation of manganese(II) complex will generate di-mu-oxo-bridged dinuclear Mn-2(III,IV) core which is very sluggish for olefin epoxidation. Adding non-redox metal ions as Lewis acid or Bronsted acid will both improve the catalytic epoxidation of olefin, and this improvement is dependent on the pK(a) of Bronsted acid, or the net charge of non-redox metals of Lewis acid. Mechanism study revealed that similar promotional effect by either Lewis or Bronsted acids was originated from a similar reaction pathway by dissociating aforementioned sluggish di-mu-oxo core. However, distinctions of reactive intermediate were also demonstrated for Lewis or Bronsted acids.

• 出版日期2017-9
• 单位华中科技大学