نتایج جستجو برای: hydrogenation
تعداد نتایج: 8711 فیلتر نتایج به سال:
Heterogeneous selective hydrogenation of ethylene carbonate (EC), a key step in indirect conversion of CO2, was realized over a copper chromite nanocatalyst prepared via a hydrothermal method followed by calcination. The selectivities towards methanol (60%) and ethylene glycol (93%) were higher than those achieved over other usual hydrogenation catalysts.
An iridium-catalyzed asymmetric hydrogenation/oxidative fragmentation of 6-substituted 5H-benzo[d] benzofuro[3,2-b]azepines has been developed, providing an efficient access to optically active 4-substituted 4,5-dihydro-1H-benzo[d]azepin-1-ones with up to 91% ee. A possible reaction pathway includes the asymmetric hydrogenation to furnish chiral cyclic amines and oxidative fragmentation under a...
Asymmetric hydrogenation of heteroaromatic compounds has emerged as a promising new route to saturated or partially saturated chiral heterocyclic compounds. In this Account, we outline recent advances in asymmetric hydrogenation of heteroaromatic compounds, including indole, quinoline, isoquinoline, furan, and pyridine derivatives, using chiral organometallic catalysts and organocatalysts.
Hydrogenation of nitriles to primary amines constitutes an atom-efficient and environmentally benign synthetic reaction. Herein we present a novel complex based on earth-abundant iron, and its application in the catalytic homogeneous hydrogenation of (hetero)aromatic, benzylic, and aliphatic nitriles to selectively form primary amines.
A novel catalytic method for the straightforward hydrogenation of carboxamides and esters to primary alcohols has been developed. Chiral modification in the ligand sphere of the well-defined Cp*Ru catalyst molecule opens up a new possibility for the development of an enantioselective hydrogenation of racemic substrates via dynamic kinetic resolution.
An efficient palladium-catalyzed asymmetric hydrogenation via capture of an active intermediate generated in situ from acid-catalyzed aza-Pinacol rearrangement has been successfully developed, providing efficient access to chiral exocyclic amines with up to 98% ee. Three-, four-, and five-membered cyclic N-sulfonyl amino alcohols are viable substrates. This study opens a new window to the appli...
A chiral phosphoric acid catalyzed asymmetric transfer hydrogenation of aromatic amines, quinolin-3-amines, was successfully developed with up to 99% ee. To supplement our previous work on the Ir-catalyzed asymmetric hydrogenation of 2-alkyl substituted quinolin-3-amines, a number of 2-aryl substituted substrates were reduced to provide a series of valuable chiral exocyclic amines with high dia...
Copper oxide supported on ceria has been investigated for the selective hydrogenation of octadecanoic acid to octadecanol. At reaction conditions of 5 bar H2 at 250 C, 75 % alcohol yield with 100 % selectivity can be achieved. The Cu species formed under the experimental conditions and ceria support likely show synergy for the selective hydrogenation of acids into alcohols.
The catalytic cycle for the production of formic acid by CO2 hydrogenation and the reverse reaction have received renewed attention because they are viewed as offering a viable scheme for hydrogen storage and release. In this Forum Article, CO2 hydrogenation catalyzed by iridium complexes bearing sophisticated N^N-bidentate ligands is reported. We describe how a ligand containing hydroxy groups...
Replacing noble metals in heterogeneous catalysts by low-cost substitutes has driven scientific and industrial research for more than 100 years. Cheap and ubiquitous iron is especially desirable, because it does not bear potential health risks like, for example, nickel. To purify the ethylene feed for the production of polyethylene, the semi-hydrogenation of acetylene is applied (80 × 10(6) ton...
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