Polystyrene stabilized iridium nanoparticles catalyzed chemo- and regio-selective semi-hydrogenation of nitroarenes to N-arylhydroxylamines

Abstract

• In the present manuscript, we have developed a protocol for chemo- and regioselective semi-hydrogenation of nitro-arenes to N-aryl hydroxyl amines under heterogeneous and recyclable Ir@PS conditions using PEG-400 as a green solvent. • The prepared Ir@PS catalyst has been well characterized through various techniques such as SEM, TEM & HR-TEM, SAED, electron dispersive X-ray (EDX) and powder X-ray crystallography and IR. • The diverse range of substituted N- aryl hydroxylamines were synthesized up to 87–99% yields at ambient temperature and shorter reaction times . Polystyrene stabilized Iridium (Ir@PS) nanoparticles (NPs) as a heterogeneous catalyst have been developed and characterized by IR, UV–Vis, SEM, TEM, EDX and XRD studies. The prepared Ir@PS catalyst showed excellent reactivity for chemo- and regio-selective controlled-hydrogenation of functionalized nitroarenes to corresponding N-arylhydroxylamine using hydrazine hydrate as reducing source and environmentally benign polyethylene glycol (PEG-400) as green solvent. The present methodology was applied for vast substrate scope and found to be compatible with wide range of reducible functional groups. The reaction performed at 85 °C or ambient temperature and completed within 5–80 minutes. The catalyst can easily be filtered out from reaction mixture and reusable.