Magnetic nanoparticle-supported ferrocenylphosphine: a reusable catalyst for hydroformylation of alkene and Mizoroki–Heck olefination

We present dopamine (dop) conjugated bis(diphenylphosphino) ferrocenylethylamine (BPPFA) functionalized magnetic nanoparticles (Fe3O4). A ferrocene ({eta(5)-C5H4-PPh2} Fe{eta(5)-C5H3-1-PPh2-2-CH(Me)NH-CH2-CH2-4Ph-1,2-OH}) ligand (dop-BPPF) has been prepared by reaction of (1-[10,2-bis(diphenylphosphino)ferrocenyl] ethyl acetate) and dopamine hydrochloride to form dop-BPPF, which was characterized by NMR, IR, FTIR, EA and FAB-MS. This ligand was anchored on ultrasmall (6-8 nm) magnetic nanoparticles (MNP) to yield Fe3O4@dop-BPPF. The resulting ferrocenylphosphine on magnetic nanoparticles was characterized by SEM, EDS, XRD, TEM, TGA, and VSM. The magnetic nature of the materials was investigated. Fe3O4@dop-BPPF exhibits very high catalytic activity for the Pd-catalyzed Mizoroki-Heck reaction and exceptionally high regioselectivity for the Rh-catalyzed hydroformylation reaction with branched aldehydes (up to > 99%). The potential of this Fe3O4@dop-BPPF as a reusable catalyst has been studied for the Mizoroki-Heck reaction, and this catalyst was robustly active even after eleven consecutive cycles.