Immobilization of A Diamine onto Fe3O4@SiO2@SBA-15 via Click Reaction: A New Pd(II) Supported Nanocatalyst for Hiyama Cross-Coupling Reaction

In this study, a new ligand, i.e. 2-(3-(2-aminophenoxy)-2-(prop-2-ynyloxy)propoxy)benzenamine (APPB), has been prepared in three steps starting from o-nitrophenole, according to Scheme 1 [1-3]. Magnetite nanoparticles (MNPs), obtained via co-precipitation method and covered by silica and mesoporous silica (SBA-15) layers, were silylated with 3-azidopropyltriethoxysilane (Fe3O4@SiO2@SBA-15-N3) [4]. The synthesized ligand (APPB) was then anchored on Fe3O4@SiO2@SBA-15 via click reaction. The core shells of the supported ligand were stirred in EtOH solution of Pd(II) to afford the supported Fe3O4@SiO2@SBA-15-APPB-Pd(II) complex, Scheme 2. The obtained nanoparticles were used in Hiyama coupling reaction of aryl halides with triethoxyphenylsilane, Scheme 3 [5]. The nanoparticles of the supported catalyst could be magnetically separated from the reaction mixture by simple magnetic decantation and reused.