Enhanced Reactivity through Equatorial Sulfur Coordination in Nonheme Iron(IV)-Oxo Complexes: Insights from Experiment and Theory.

Sulfur ligation in metalloenzymes often gives the active site unique properties, whether it is the axial cysteinate ligand in the cytochrome P450s or the equatorial sulfur/thiol ligation in nonheme iron enzymes. To understand sulfur ligation to iron complexes and how it affects the structural, spectroscopic, and intrinsic properties of the active species and the catalysis of substrates, we pursued a systematic study and compared sulfur with amine-ligated iron(IV)-oxo complexes. We synthesized and characterized a biomimetic NS-ligated iron(IV)-oxo complex and compared the obtained results with an analogous N-ligated iron(IV)-oxo complex.

Defluorination of Fluorophenols by a Nonheme Iron(IV)-Oxo Species: Observation of a New Intermediate Along the Reaction.

High-valent iron(IV)-oxo intermediates are versatile oxidants in the biotransformation of various substrates by metalloenzymes and catalyze essential reactions for human health as well as in the biodegradation of toxic organic pollutants in the environment. Herein, we report a biomimetic system that efficiently reacts with halophenols through defluorination reactions and characterize various short-lived intermediates along the reaction mechanism. We study the reactivity pattern of a nonheme iron(IV)-oxo species with a series of trihalophenols (X=F, Cl, Br).

Oxidative dehalogenation of halophenols by high-valent nonheme iron(IV)-oxo intermediates.

Mononuclear high-valent iron(IV)-oxo intermediates are excellent oxidants towards oxygenation reactions by heme and nonheme metalloenzymes and their model systems. One of the most important functions of these intermediates in nature is to detoxify various environmental pollutants. Organic substrates, such as halogenated phenols, are known to be water pollutants which can be degraded to their less hazardous forms through an oxidation reaction by iron(IV)-oxo complexes.

A comprehensive insight into aldehyde deformylation: mechanistic implications from biology and chemistry.

Aldehyde deformylation is an important reaction in biology, organic chemistry and inorganic chemistry and the process has been widely applied and utilized. For instance, in biology, the aldehyde deformylation reaction has wide differences in biological function, whereby cyanobacteria convert aldehydes into alkanes or alkenes, which are used as natural products for, e.g.

Sluggish reactivity by a nonheme iron(iv)-tosylimido complex as compared to its oxo analogue.

High-valent iron-nitrido intermediates have been postulated as reactive intermediates in various enzymes, including the nitrogenases and the cytochromes P450, but so far few have been trapped and characterized. As little is known about their oxidative and spectroscopic properties, we decided to create biomimetic models of iron(iv)-imido complexes and compare their structure and reactivity with analogous iron(iv)-oxo systems. In this work we report the synthesis and spectroscopic characterization of a novel [Fe(NTs)(Bntpen)] complex (Bntpen = N-benzyl-N,N,N-tris(pyridine-2-ylmethyl)ethane-1,2-diamine) and study its reactivity patterns with respect to hydrogen atom abstraction and nitrogen atom transfer reactions.

Hydrogen by Deuterium Substitution in an Aldehyde Tunes the Regioselectivity by a Nonheme Manganese(III)-Peroxo Complex.

Mononuclear nonheme Mn -peroxo complexes are important intermediates in biology, and take part in oxygen activation by photosystem II. Herein, we present work on two isomeric biomimetic side-on Mn -peroxo intermediates with bispidine ligand system and reactivity patterns with aldehydes. The complexes are characterized with UV/Vis and mass spectrometric techniques and reaction rates with cyclohexane carboxaldehyde (CCA) are measured.