Using pd(cf(3)co(2))2/(S,S)-f-Binaphane as the catalyst, an efficient enantioselective synthesis of sultams was developed via asymmetric hydrogenation of the corresponding cyclic imines with high enantioselectivities. The hydrogenation products can be conveniently transformed to chiral homoallylic amines without loss of enantioselectivity.

Cyclometalation of [Cp*IrCl(2)](2) with ketimine ligands generated very active catalysts for transfer hydrogenation of imines as well as reductive amination. The synthesis and X-ray diffraction structures of three such complexes are disclosed in this paper. The hydrides of two complexes, key intermediates in hydrogenation, have been isolated and their structures determined by X-ray diffraction ...

Keywords: Model catalysis Nickel Palladium Platinum d-band Ethylene de-/hydrogenation a b s t r a c t Ethylene hydrogenation catalyzed at 300 K by 1–1.5 nm nanoparticles of Ni, Pd and Pt supported on MgO (1 0 0) with a narrow size-distribution, as well as the deactivation under reaction conditions at 400 K, was investigated with pulsed molecular beam experiments. Ni nanoparticles deactivate rea...

Optically active six-membered rings such as cyclohexanes and piperidines play an important role as biologically active building blocks and key intermediates in organic chemistry. Catalytic asymmetric hydrogenation of aromatic and heteroaromatic compounds is one of themost straightforward routes for the formation of these saturated or partially saturated molecules. Recently, tremendous progress ...

Despite significant progress in the area of asymmetric hydrogenation, the enantioselective hydrogenation of aromatic and heteroaromatic compounds still remains a major challenge. Only a few examples with moderate enantioselectivity, which rely on unique catalyst systems and suffer from a limited scope of suitable substrates, have been described so far. There are several reasons that might expla...

[reaction: see text] The chiral disphosphines with tunable dihedral angles (TunaPhos) have been used for asymmetric hydrogenation of enol acetates and dihedral-angle-dependent enantioselectivities were observed. C2-TunaPhos has been proved to be effective for Ru-catalyzed asymmetric hydrogenation of electron-deficient and other enol acetates.

Few methods permit the hydrogenation of alkenes to a thermodynamically favored configuration when steric effects dictate the alternative trajectory of hydrogen delivery. Dissolving metal reduction achieves this control, but with extremely low functional group tolerance. Here we demonstrate a catalytic hydrogenation of alkenes that affords the thermodynamic alkane products with remarkably broad ...

The Rh-TangPhos complex is an efficient hydrogenation catalyst for making chiral beta-amino acid derivatives. With the Rh-TangPhos system, high enantioselectivities (up to 99.6%) and turnover numbers have been obtained in the hydrogenation of E/Z isomeric mixtures of both beta-alkyl and beta-aryl beta-(acylamino)acrylates. [reaction: see text]

The one-step dehydration, decarboxylation and hydrogenation of the bio-based and widely available citric acid is presented. This reaction sequence yields methylsuccinic acid with yields of up to 89%. Optimal balances between the reaction rates of the different steps were found by varying the hydrogenation catalyst and the reaction parameters (H2 pressure, pH, temperature, time and catalyst-to-s...

Finely-tuned ruthenium-catalyzed highly chemoselective and enantioselective hydrogenation of γ-halo-γ,δ-unsaturated-β-keto esters at the carbonyl group was achieved under neutral reaction conditions (ee up to 97%). Both olefin and alkenyl halogen moieties, which are labile under hydrogenation conditions, remained untouched during the reaction.