Superparamagnetic Fe(OH)3@Fe3O4 nanoparticles: An efficient and recoverable catalyst for transamidation of primary carboxamides, phthalimide, urea and thiourea with amines

The amide bond formation is an important functional group in chemistry and nature due to its presence in polymers, dyes, peptides, and protein structures [1]. Transamidation of amides with amines is an attractive method for exchanging the constituents of two different amide groups. Due to the high stability and easy separation of the catalyst from the reaction mixture by using an external magnet, magnetic nanoparticles-supported catalysts have been successfully deployed in a variety of important organic reactions [2]. As part of our continuing interests in using magnetic nanoparticles as catalyst support in organic reactions, we have recently reported the results obtained for the tandem oxidative amidation of alcohols with amine hydrochloride salts using superparamagnetic Fe(OH)3@Fe3O4 nanoparticles catalyst [3].To further establish other organic transformations with our catalyst, herein, we describe an inexpensive, magnetically recoverable and environmentally friendly catalytic system (Fe(OH)3@Fe3O4) for the transamidation of primary carboxamides, phthalimide, urea and thiourea with amines (Figure 1).