Modeling Non-Heme Iron Halogenases: High-Spin Oxoiron(IV)-Halide Complexes That Halogenate C-H Bonds

Mayank Puri, Achintesh N. Biswas, Ruixi Fan, Yisong Guo, Lawrence Que

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

The non-heme iron halogenases CytC3 and SyrB2 catalyze C-H bond halogenation in the biosynthesis of some natural products via S = 2 oxoiron(IV)-halide intermediates. These oxidants abstract a hydrogen atom from a substrate C-H bond to generate an alkyl radical that reacts with the bound halide to form a C-X bond chemoselectively. The origin of this selectivity has been explored in biological systems but has not yet been investigated with synthetic models. Here we report the characterization of S = 2 [FeIV(O)(TQA)(Cl/Br)]+ (TQA = tris(quinolyl-2-methyl)amine) complexes that can preferentially halogenate cyclohexane. These are the first synthetic oxoiron(IV)-halide complexes that serve as spectroscopic and functional models for the halogenase intermediates. Interestingly, the nascent substrate radicals generated by these synthetic complexes are not as short-lived as those obtained from heme-based oxidants and can be intercepted by O2 to prevent halogenation, supporting an emerging notion that rapid rebound may not necessarily occur in non-heme oxoiron(IV) oxidations.

Original languageEnglish (US)
Pages (from-to)2484-2487
Number of pages4
JournalJournal of the American Chemical Society
Volume138
Issue number8
DOIs
StatePublished - Mar 2 2016

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Halogenation
Oxidants
Iron
Hydrogen
Biosynthesis
Biological systems
Substrates
Cyclohexane
Biological Products
Heme
Amines
Atoms
Oxidation

Cite this

Modeling Non-Heme Iron Halogenases : High-Spin Oxoiron(IV)-Halide Complexes That Halogenate C-H Bonds. / Puri, Mayank; Biswas, Achintesh N.; Fan, Ruixi; Guo, Yisong; Que, Lawrence.

In: Journal of the American Chemical Society, Vol. 138, No. 8, 02.03.2016, p. 2484-2487.

Research output: Contribution to journalArticle

Puri, Mayank ; Biswas, Achintesh N. ; Fan, Ruixi ; Guo, Yisong ; Que, Lawrence. / Modeling Non-Heme Iron Halogenases : High-Spin Oxoiron(IV)-Halide Complexes That Halogenate C-H Bonds. In: Journal of the American Chemical Society. 2016 ; Vol. 138, No. 8. pp. 2484-2487.
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