Immobilization of Rh(I)-N-Xantphos and Fe(II)-C-Scorpionate onto Magnetic Nanoparticles: Reusable Catalytic System for Sequential Hydroformylation/Acetalization

Two heterogeneous catalysts, MNP@SiO2-N-Xantphos/Rh(I) and MNP@SiO2-NH-C-scorpionate/Fe(II), were prepared by reaction of chloro-functionalized MNP@SiO2 with N-Xantphos amino-functionalized iron(II)/C-allyl-scorpionate through nucleophilic substitution hydroaminomethylation reactions, respectively. All catalysts characterized using standard spectroscopic means, transmission electron microscopy (TEM), thermogravimetry (TG), inductively coupled plasma optical emission spectrometry (ICP-OES). An active highly selective one-pot hydroformylation/acetalization homogeneous system for the transformation terminal substituted olefins (including terpenes) onto ethyl acetals is described. A synergic effect bimetallic Rh(I)/P Fe(II)/C-scorpionate disclosed first time. The further sequential use MNP@SiO2-NH-C-scorpionate/Fe(II) in reactions allows direct olefin acetals, keeping activity selectivity. Both easily recovered magnetic separation reused negligible loss activity/selectivity, after six reutilization cycles.