Unraveling the Mechanism of Hydrogen Atom Transfer by a Nickel-Hypochlorite Species and the Influence of Electronic Effects.

The oxidation of hydrocarbons is an important chemical transformation with relevance to biology and industry. Ni-catalyzed transformations are more scarce compared to Mn or Fe but have gained attention in recent years, affording efficient oxidations. Understanding the mechanism of action of these catalysts, including the detection and characterization of the active nickel-oxygen species, is of interest to design better catalysts.

Proton-triggered chemoselective halogenation of aliphatic C-H bonds with nonheme Fe-oxo complexes.

Halogenation of aliphatic C-H bonds is a chemical transformation performed in nature by mononuclear nonheme iron dependent halogenases. The mechanism involves the formation of an iron(IV)-oxo-chloride species that abstracts the hydrogen atom from the reactive C-H bond to form a carbon-centered radical that selectively reacts with the bound chloride ligand, a process commonly referred to as halide rebound. The factors that determine the halide rebound, as opposed to the reaction with the incipient hydroxide ligand, are not clearly understood and examples of well-defined iron(IV)-oxo-halide compounds competent in C-H halogenation are scarce.