Modeling TauD-J: a high-spin nonheme oxoiron(IV) complex with high reactivity toward C-H bonds

J Am Chem Soc. 2015 Feb 25;137(7):2428-31. doi: 10.1021/ja511757j. Epub 2015 Feb 17.

Abstract

High-spin oxoiron(IV) species are often implicated in the mechanisms of nonheme iron oxygenases, their C-H bond cleaving properties being attributed to the quintet spin state. However, the few available synthetic S = 2 Fe(IV)═O complexes supported by polydentate ligands do not cleave strong C-H bonds. Herein we report the characterization of a highly reactive S = 2 complex, [Fe(IV)(O)(TQA)(NCMe)](2+) (2) (TQA = tris(2-quinolylmethyl)amine), which oxidizes both C-H and C═C bonds at -40 °C. The oxidation of cyclohexane by 2 occurs at a rate comparable to that of the oxidation of taurine by the TauD-J enzyme intermediate after adjustment for the different temperatures of measurement. Moreover, compared with other S = 2 complexes characterized to date, the spectroscopic properties of 2 most closely resemble those of TauD-J. Together these features make 2 the best electronic and functional model for TauD-J to date.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biomimetic Materials / chemistry*
  • Carbon / chemistry*
  • Hydrogen / chemistry*
  • Iron / chemistry*
  • Mixed Function Oxygenases / metabolism*
  • Models, Molecular
  • Molecular Conformation
  • Organometallic Compounds / chemistry*
  • Oxidation-Reduction

Substances

  • Organometallic Compounds
  • Carbon
  • Hydrogen
  • Iron
  • Mixed Function Oxygenases
  • taurine-alpha-ketoglutarate dioxygenase