Magnetic Nanoparticles-Supported Platinum Nanoparticles

Significance

Platinum nanoparticles supported by magnetic nanoparticles that were modified with ionic liquid were prepared and applied to the selective hydrogenation. Thus, imidazole 1 reacted with octyl chloride 2 at 120 °C to give the imidazolium chloride 3 in 97% yield (eq. 1). Treatment of 3 with the magnetic nanoparticles, Fe₃O₄, in the presence of ammonia afforded ionic liquid modified Fe₃O₄ 4. Anion exchange reaction of 4 with K₂PtCl₄ followed by reduction with hydrazine provided the supported platinum nanoparticles 5. The hydrogenation of diphenylacetylene was carried out in the presence of 2.5 mol% of catalyst 5 under 200 psi of hydrogen at 90 °C for 16 h to give cis-stilbene as a major product in 95% yield (eq. 2). Cinnam­aldehyde was chemoselectively hydrogenated under similar reaction conditions to afford 3-phenylprop-2-en-1-ol in 99% yield (eq. 3).