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Combination of Karstedt's catalyst or Pt(dba)2 [dba: dibenzylideneacetone] with activated carbon was found to be an efficient catalyst system for the arene hydrogenation of a variety of functionalized aromatic compounds. The reaction proceeds at ambient temperature under atmospheric hydrogen pressure to afford the corresponding carbo‐ and heterocyclic compounds in good to high yields without contamination of the metallic species. The addition of activated carbon in the reaction mixture was proved to be crucial for not only sustaining the catalytic activity but also trapping the platinum species effectively after the reaction. Similar sustaining effect was observed by the addition of vinyl siloxane derivatives. [ABSTRACT FROM AUTHOR]

Abstract: Palladium nanoparticles supported on 5 %‐nitrogen‐doped, herringbone‐type carbon nanofibers (Pd/N‐CNF‐H), which are prepared by thermally decomposing [Pd2(dba)3⋅CHCl3] (dba=dibenzylideneacetone) in toluene in the presence of N‐CNF‐H, were found to be an efficient catalyst for the chemoselective hydrogenation of alkenyl and nitro moieties in benzyl‐protected alcohols and carboxylic acid derivatives with high turnover frequencies: the hydrogenation reactions of these functional groups proceeded smoothly even at ambient temperature under atmospheric H2 pressure, and the benzyl protecting groups in the molecules remained intact. Moreover, the recovered Pd/N‐CNF‐H catalyst could be reused without loss of its catalytic activity or chemoselectivity. The Pd/N‐CNF‐H catalyst also acted as an effective hydrogenation catalyst for the reduction of aromatic ketones to the corresponding benzyl alcohol derivatives with good to high product selectivity. [ABSTRACT FROM AUTHOR]

The reaction of three types of carbon nanofibers (CNFs; platelet: CNF-P, tubular: CNF-T, herringbone: CNF-H) with Ir4(CO)12 in mesitylene at 165 °C provided the corresponding CNF-supported iridium nanoparticles, Ir/CNFs (Ir content=2.3-2.6 wt. %). Transmission electron microscopy (TEM) studies of these Ir/CNF samples revealed that size-controlled Ir nanoparticles (average particle size of 1.1-1.5 nm) existed on the CNFs. Among the three Ir/CNF samples, Ir/CNF-T showed an excellent catalytic activity and chemoselectivity towards hydrogenation of functionalized nitroarenes and imines; the corresponding aniline derivatives were obtained with high turnover numbers at ambient temperature under 10 atm of H2, and the catalyst is reusable. Ir/CNF-T was also effective for the reductive N-alkylation of anilines with carbonyl compounds. [ABSTRACT FROM AUTHOR]

The article discusses a study which synthesized palladium nanoparticles supported on nitrogen-doped carbon nanofiber (N-CNF-H) by thermally decomposing Pd2(dba)3CHCl3 in the presence of N-CNF-H. The study found that the Pd/N-CNF-H compounds act as efficient catalysts in the partial hydrogenation of internal alkynes to the corresponding (Z)-alkenes. It also suggested the significance of N-CNF-H in the preparation of heterogenous poisoning catalysts.

Use of Ru/CNF-P, nanoruthenium particles dispersed on a nanocarbon fiber support, realizes highly efficient catalytic partial hydrogenation of 1,1′-bi-2-naphthol and -naphthyl- amine derivatives. The reactions proceed in high turnover numbers without racemization of the axial chirality, offering a practical procedure for the production of optically pure 5,5′,6,6′,7,7′,8,8′-octahydro- 1,1′-binaphthyls in good to high yields. [ABSTRACT FROM AUTHOR]

The catalyst consisting of carbon nanofibers with tubular graphite layers is reused five times without loss of activity. [ABSTRACT FROM AUTHOR]