Copper-catalyzed Goldberg-type C-N coupling in deep eutectic solvents (DESs) and water under aerobic conditions

摘要

An efficient and selective N-functionalization of amides is first reported via a Cul-catalyzed Goldberg-type C-N coupling reaction between aryl iodides and primary/secondary amides run either in Deep Eutectic Solvents (DESs) or water as sustainable reaction media, under mild and bench-type reaction conditions (absence of protecting atmosphere). Higher activities were observed in an aqueous medium, though the employment of DESs expanded and improved the scope of the reaction to include also aliphatic amides. Additional valuable features of the reported protocol include: (ⅰ) the possibility to scale up the reaction without any erosion of the yield/reaction time; (ⅱ) the recyclability of both the catalyst and the eutectic solvent up to 4 consecutive runs; and (ⅲ) the feasibility of the proposed catalytic system for the synthesis of biologically active molecules.