Mechanochemical Aminocarbonylation of Unactivated Arenes Leveraging in Situ Thianthrenation and Using FeBr ₂ (CO) ₄ as a CO Surrogate

Here, we present a convergent synthesis of aromatic carboxamides from unactivated arenes using FeBr2(CO)4 as a CO source and the corresponding amine. The reaction involves the in situ formation of arene thianthrenium salts, which participate in the Pd-catalyzed carbonylation step, affording a broad range of carboxamides, including late-stage derivatization of several complex, medicinally and biologically relevant compounds. Mechanistic studies suggest that CO coordination precedes oxidative oxidation, thereby resulting in a highly selective carbonylative process.