# Flash Communication: Flexibility of a Biologically Inspired Ligand Framework for Intramolecular C–H Activation

## TL;DR

This paper explores how a special ligand framework can help stabilize high-valent iron complexes involved in C–H bond activation, a key process in organic oxidation reactions.

## Contribution

The study introduces a novel nonporphyrin tripodal ligand framework with a secondary coordination sphere for stabilizing reactive iron species.

## Key findings

- An Fe(III)-alkoxide complex was formed through intramolecular C–H bond activation.
- Attempts to observe an Fe(IV)-oxo complex were unsuccessful.
- The ligand's electronic environment is crucial for stabilizing reactive iron species.

## Abstract

High-valent iron
complexes play a crucial role in the
oxidation
of organic substrates, especially in C–H bond functionalization
reactions in biology. This paper investigates the reactivity of nonporphyrin
tripodal ligands featuring a secondary coordination sphere, focusing
on their prospective ability to stabilize high-valent iron-oxo species.
Using NMR spectroscopy and X-ray crystallography, we detail the formation
of an Fe(III)-alkoxide complex through intramolecular C–H bond
activation, providing insight into the potential transient formation
of a high-valent iron-oxo intermediate. While attempts to observe
an Fe(IV)-oxo complex were unsuccessful, our findings underscore the
significance of the ligand electronic environment in stabilizing reactive
iron species for C–H bond activation.