A Preliminary Study of Cobalt-Catalyzed C—H/N—H Annulation in a Non-Conventional Solvent

This study investigates the influence of a non-ionic deep eutectic solvent on a cobalt-catalyzed C—H activation reaction. In this context, we demonstrate the feasibility of a cobalt-catalyzed one-step activation of Csp2—H and N—H bonds in benzosulfonamides, directed by aminoquinoline, with symmetrical 1,3-diynes for the synthesis of benzosultams. Rather than serving solely as a solvent replacement, the non-ionic deep eutectic solvent acts as a structured hydrogen-bonding reaction medium compatible with cobalt-catalyzed C—H activation. The study demonstrates that cobalt-catalyzed C—H activation can proceed with substrate-dependent product selectivity under these conditions, although further optimization is required to improve conversion and catalytic efficiency. These findings provide initial insights into solvent effects on cobalt-catalyzed C—H activation under non-conventional reaction media.