Rh‐Complex Supported on Magnetic Nanoparticles as Catalysts for Hydroformylations and Transfer Hydrogenation Reactions

Abstract

Herein, we describe a facile protocol for the phosphine complex of Rh anchored on the ultrasmall magnetic nanoparticles for transfer hydrogenation and hydroformylation reactions. A diphenylphosphino‐ferrocenylethyl amine was conjugated with dopamine hydrochloride to form dop‐Fc, which was then anchored on the surface of magnetic nanoparticles to produce Fe3O4@dop‐Fc. The prepared materials were complexed with a Rh precursor as a catalytic center. XRD, FTIR, SEM, TEM, and XPS were used to investigate the structure and its reactivity. Rh‐complexes of Fe3O4@dop‐Fc were used to convert terminal olefin to aldehyde using syngas (CO : H2 1 : 1) under pressure, obtaining up to 99% selectivity for branched aldehyde. The wide applicability of the Fe3O4@dop‐Fc−Rh construct was tested for the selective transfer hydrogenations of nitroarene and N‐heteroarene. Particularly, quinoline was quantitatively hydrogenated to 1,2,3,4‐tetrahydroquinoline(py‐THQ) using tetrahydroxydiboron (THDB). Also, the functional group tolerance in the reduction of nitroarene and styrene was evaluated. The robustness of the catalyst was tested by reusing it for multiple cycles.

Facile Transfer Hydrogenation of N-Heteroarenes and Nitroarenes Using Magnetically Recoverable Pd@SPIONs Catalyst

“…The reduction of nitroarenes to corresponding amines is a frequently used process in the industry . For instance, anilines, which are important precursors for rubber chemicals, pesticides, dyes, and pharmaceuticals, are obtained from the nitroarenes hydrogenation reactions. ,, However, the challenge with the reduction process is achieving high product selectivity in the presence of multiple competitive functional groups with high reaction rates . In addition, the prospect of multiple intermediate product formations, such as azobenzene, azoxybenzene, or hydroxylamines, during the hydrogenation process cannot be ruled out .…”

“…An aqueous solution containing Fe 2+ and Fe 3+ (Fe 2+ /Fe 3+ = 1:2 molar ratio), was reduced by aqueous NH 3 , forming highly aggregated black-colored magnetic nanoparticles eq 1 . 17 , 29 , 30 …”

Iridium Nanoparticles on SPIONs as a Catalyst for N‐Heteroarene and Styrene Hydrogenation Reactions and their DFT Studies

“…effectively employed dendron polymer as a catalyst under high pressure to demonstrate the surface functionalization of SPIONs in this setting [49] . Our previous work on heterogeneous metal nanoparticle catalysts on SPIONs as a support for various organic functional group interconversions prompted us to investigate the catalytic behavior of different active metals on the support [50,51] . Here, we developed Ir nanoparticles decorated with SPIONs as a hydrogenation catalyst for quinoline and styrene under molecular hydrogen pressure (Figure 1).…”