Sterically controlled isodesmic late-stage C-H iodination of arenes.

Aryl iodides are key motifs in organic chemistry due to their versatility as linchpins in metal-mediated cross-coupling reactions for synthesis and drug discovery. These scaffolds are typically prepared indirectly from prefunctionalized starting materials or via electrophilic aromatic iodination protocols. These methods are limited to specific regioisomers by their inherent selectivities and/or the availability of the required starting materials. Herein, we describe the sterically controlled iodination of arenes through an isodesmic C-H/C-I bond metathesis approach enabled by our dual ligand-based catalysts for arene-limited nondirected C-H activation. The protocol gives direct access to a complementary product spectrum with respect to traditional methods. Its synthetic utility is demonstrated by a broad scope and the suitability for late-stage modification.