Synthesis, characterization and catalytic performance of Pd(II) complex immobilized on Fe3O4@SiO2 nanoparticles for the ligand-free cyanation of aryl halides using K4Fe(CN)6

This work shows the preparation of a novel magnetic catalyst via immobilization of Pd(II)-N-benzyl-N-(4-bromophenyl)-5-amino-1H-tetrazole complex on the Fe3O4@SiO2 nanoparticles (NPs). The application of Fe3O4@SiO2 NPs supported Pd(II)-N-benzyl-N-(4-bromophenyl)-5-amino-1H-tetrazole complex [Fe3O4@SiO2-BAT-Pd(II)] nanocatalyst is described for the cyanation of aryl iodides and bromides to the corresponding aryl nitriles using potassium hexacyanoferrate(II) [K4Fe(CN)(6)] as a non-toxic and economic cyanating agent under ligand- and additive-free conditions. Some aryl nitriles were efficiently synthesized from the corresponding aryl bromides and iodides in the presence of Fe3O4@SiO2-BAT-Pd(II) nanocomplex. The core-shell nanocomplex demonstrated the superior catalytic performance for the synthesis of synthetically valuable aryl nitriles within good to excellent yields. This process eliminates the need to handle highly toxic metal cyanides, and it can be easily recovered and reused for six consecutive runs with no decreasing of its catalytic capability. Highlights Preparation of Pd(II) complex immobilized on Fe3O4@SiO2 nanoparticles [Fe3O4@SiO2-BAT-Pd(II) nanocomplex]. Characterization of Fe3O4@SiO2-BAT-Pd(II) nanocomplex using XRD, FT-IR, EDS, VSM, TEM and FESEM analyses. Catalytic cyanation of the various aryl halides with K4Fe(CN)(6) under ligand-free conditions. The nanocomplex can be recovered and isolated six times with no significant loss of its catalytic ability.