C–P bond construction catalyzed by NiII immobilized on aminated Fe3O4@TiO2 yolk–shell NPs functionalized by (3-glycidyloxypropyl)trimethoxysilane (Fe3O4@TiO2 YS-GLYMO-UNNiII) in green media

Abstract

Ni^II immobilized on aminated Fe₃O₄@TiO₂ yolk–shell NPs functionalized by (3-glycidyloxypropyl)trimethoxysilane (Fe₃O₄@TiO₂ YS-GLYMO-UNNi^II) was prepared as a stable, highly efficient, and reusable magnetic nanostructured catalyst for the C–P cross coupling reaction. A variety of spectroscopic and microscopic techniques such as Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), EDS-mapping, thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and CHNS analysis were used to characterize the synthesized nanostructured catalyst. The characterization determined that the nanostructured catalyst is superparamagnetic in nature and structured as core–shell and its average particle size is 30–32 nm. The catalytic activity of this new magnetic nanostructured catalyst (Fe₃O₄@TiO₂ YS-GLYMO-UNNi^II) was examined in the C–P cross coupling reaction of aryl halides/aryl boronic acids/styrene/phenylacetylene with diethylphosphite/triethylphosphite in the presence of WERSA so that arylphosphonates/vinylphosphonate/alkynylphosphonate could be prepared in a short period of time. In all the cases, the nanostructured catalyst could be easily recovered magnetically for at least seven runs and a simple work-up procedure was used to isolate the obtained products. The present methodology proved to be quite suitable for scale-up and commercialization.