# Regioselective Iodination of Arenes Using Iron- or Silver-Catalyzed Activation of N‑Iodosaccharin

## TL;DR

A new method enables selective iodination of arenes using iron or silver catalysts, offering mild conditions and compatibility with complex molecules.

## Contribution

A regioselective arene iodination method using Lewis acid activation of N-iodosaccharin is introduced, with broad functional group tolerance and applicability.

## Key findings

- Iron(III) chloride and silver(I) triflimide catalyze efficient iodination of electron-rich arenes at room temperature.
- The method is compatible with cross-coupling reactions, enabling one-pot halogenation and arylation sequences.
- The approach works on complex substrates like natural products and pharmaceuticals.

## Abstract

Aryl iodides are privileged intermediates in organic
synthesis,
underpinning cross-coupling chemistry, late-stage functionalization,
and radiolabeling in medicinal chemistry. However, regioselective
arene iodination remains a challenge, as traditional electrophilic
iodination methods often require harsh conditions, exhibit poor selectivity,
or suffer from limited functional group tolerance and substrate scope.
We report a rapid and regioselective arene iodination enabled by Lewis
acid activation of N-iodosaccharin. Iron­(III) chloride
and silver­(I) triflimide were found to catalyze the efficient iodination
of a broad range of electron-rich arenes at room temperature. The
method displayed broad functional group tolerance and was applicable
to complex substrates, including natural products and pharmaceuticals.
Furthermore, the iodination was found to be compatible with cross-coupling
reactions, allowing one-pot halogenation and arylation sequences for
direct access to biaryl compounds.