Construction of Biaryl Sulfonamides via Pd(II)-Catalyzed Cross-Coupling of C(sp2)‑H Bonds with Iodobenzenesulfonamides

This study describes the utility of Pd(II)-catalyzed C–H arylation of benzamides for constructing biaryl sulfonamides. Sulfonamides are known for their promising applications in pharmaceuticals and agrochemicals. A literature review revealed that biaryl sulfonamides were generally constructed via the traditional cross-coupling reactions. We report a progressive method for obtaining biaryl sulfonamides via the Pd(II)-catalyzed bidentate directing group (8-aminoquinoline or picolinamide)-assisted cross-coupling of sp2 C–H bonds of aromatic carboxamides with iodobenzenesulfonamides. After the C–H arylation reactions, we attempted the removal of the 8-aminoquinoline from the synthesized biaryl scaffolds possessing the carboxamide and sulfonamide moieties using triflic acid. In some cases, we observed the occurrence of decarboxylation and Friedel–Crafts acylation, affording interesting aromatic scaffolds possessing the sulfonamide moiety. The current work contributes toward developing alternative ways for assembling various biaryl sulfonamides.