Sterically Controlled C(sp²)-H Carboxylation and Formylation: A Complementary Strategy to S_EAr Approaches

Carboxyl- and formyl-substituted arenes are key motifs in organic chemistry, typically prepared via electrophilic aromatic substitution (S_EAr) reactions. S_EAr reactions hold tremendous synthetic value, and one of the key advantages is their predictable regioselectivity. Conversely, certain positions remain out of reach, such as sterically accessible but comparably electron-poor sites. Herein, we describe a nondirected C(sp²)-H carboxylation and formylation of arenes enabled by a dual ligand-based catalyst. By optimizing the steric control of a nondirected olefination of arenes and combining this method with two distinct protocols for the subsequent oxidative cleavage of alkenes, we can generate a complementary set of regioisomeric products. The synthetic utility is demonstrated by a broad scope with suitability for late-stage functionalization.