Catalytic Hydrogenation Of Acetophenone Research Articles

Impact of Oxygen-Containing Groups on Pd/C in the Catalytic Hydrogenation of Acetophenone and Phenylacetylene

Impact of Oxygen-Containing Groups on Pd/C in the Catalytic Hydrogenation of Acetophenone and Phenylacetylene

Microwave-Assisted Synthesis of Zirconium Phosphate Nanoplatelet-Supported Ru-Anadem Nanostructures and Their Catalytic Study for the Hydrogenation of Acetophenone

The catalytic hydrogenation of organic compounds containing carbonyl groups has been extensively studied and widely used in industrial processes. Herein, we report the preparation of a novel nanomaterial, α-zirconium phosphate (α-ZrP) nanoplatelet-supported ruthenium nano-anadem catalyst, which possesses high selectivity in the catalytic hydrogenation of aromatic ketones. The α-ZrP nanoplatelets were prepared using a modified reflux method. Through an ion-exchange and reduction reaction pathway, ruthenium nanoparticles were loaded on ZrP to produce Ru-ZrP with a nano-anadem structure. The successful synthesis of Ru-ZrP composites is supported by a series of characterization techniques (PXRD, SEM, TEM, EDS, XPS, FT-IR, etc.). Compared with pure ZrP nanoplatelets, the catalytic hydrogenation of acetophenone has been dramatically improved when using Ru-ZrP. Full conversion was achieved at room temperature, and the yield of 1-cyclohexylehtanol was up to 95%. The effects of reaction time, reaction temperature, and hydrogen pressure were investigated. The investigation illustrates that there are two proposed reaction pathways in the hydrogenation of acetophenone, which are further supported by computational analyses. Recycling experiments indicate that the Ru-ZrP material could be reused four times without a noticeable activity decrease.

Influence of gold nanoparticles applied to catalytic hydrogenation of acetophenone with cationic complexes containing ruthenium

AuNPsn−have improved the catalytic activity of complexes that have biphosphines with tensioned or large bite angles, while for complexes that have biphosphines with a strong chelate effect a decrease was observed.

Synthesis and Structures of Ruthenium and Iron Complexes Bearing an Unsymmetrical Pincer‐type Ligand with Protic Pyrazole and Tertiary Aminoalkyl Arms

AbstractA protic pyrazole‐armed NNN‐type pincer ligand 2‐(5‐tert‐butylpyrazol‐3‐yl)‐6‐(diethylaminomethyl)pyridine (LH) with a tertiary aminomethyl tether was synthesized as a new template for metal‐ligand bifunctional catalysts furnished with proton‐responsive pyrazole and hemilabile amine as the cooperating units. Treatment of LH with trans‐[RuCl2(Me2SO)4] and anhydrous FeCl2 led to the formation of the pincer‐type ruthenium complex [RuCl2(Me2SO‐S)(LH)] (2) and iron complex [FeCl2(LH)] (3), respectively. Detailed structures of 2·CH2Cl2 and 3 were determined by X‐ray crystallography. The Brønsted acidic pyrazole NH group proved to be engaged in intra‐ or intermolecular hydrogen bonding. Catalytic hydrogenation of acetophenone with the protic pincer‐type complexes 2 and 3 was also investigated.

Catalytic hydrogenation of acetophenone over shape controlled Pd catalysts supported on sheet-like NiO

Cubic, truncated octahedral and hexagonal/triangular Pd/NiO supported catalysts were synthesized and applied in the hydrogenation of acetophenone. The catalysts were characterized by XRD, TEM, XPS and TG–DCS, and the catalytic performances for selective hydrogenation of acetophenone were evaluated under the condition of 80°C, 3h and 1.5MPa pressure of hydrogen in alcohol media without additives. Results showed that the conversion of 19% and selectivity of 92% were achieved by hexagonal/triangular Pd/NiO catalyst. And when truncated octahedral Pd/NiO was used as the catalyst, the conversion of acetophenone was raised to 40%, while the selectivity of 1-phenethanol decreased to 89%. As to cubic Pd/NiO catalyst, the conversion to further improved to 70% and the selectivity of 1-phenethanol went down to 80%.

Simple in Situ Monitoring of a Complex Catalytic Reaction Network at High Pressure by Attenuated Total Reflection Fourier Transform Infrared Spectroscopy

Attenuated total reflection (ATR) Fourier transform infrared (FT-IR) in situ measurements were performed during the catalytic hydrogenation of acetophenone under high pressure (5.0 MPa). The catalyst used was a suspension of rhodium nanoparticles in an ionic liquid. At the highest temperature used (80 degrees C), the selectivity of the hydrogenation to 1-phenylethanol dropped from 80% in the beginning of the reaction, when acetylcyclohexane was the main side product, to less than 50% after a few hours of experiment because of the consecutive hydrogenation of 1-phenylethanol to ethylcyclohexane. The evolution of the concentrations of reactant and products was quantified using flawless spectra of pure components with a classical least squares (CLS) multivariate method applied to several ranges of the mid-infrared spectra. The only variable parameters of the analysis are the concentrations of each component themselves and the baseline shift of the spectrum during the reaction. The advantage of using multivariate analysis over the analysis of a single vibrational band, as well as the limitations of this type of spectral analysis, are discussed.

Catalytic Hydrogenation of Acetophenone with Hydrogen Transfer over Chiral Diamine Rhodium(I) Complexes.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Catalytic Hydrogenation of Acetophenone with Hydrogen Transfer over Chiral Diamine Rhodium(I) Complexes

The catalytic activity and stereoselectivity of Rh(I) complexes with C 2-symmetric chiral diamines, (4S,5S)-3,4-isopropylidenedioxy-1,4-butanediamine and (4S,5S)-N,N,N',N'-tetramethyl-3,4-isopropylidenedioxy-1,4-butanediamine [skeletal analogs of 2,3-dihydroxy-2,3-O-isopropylidene-1,4-bis(diphenylphosphino)butane (DIOP)], were studied in hydrogen transfer from 2-propanol to acetophenone in the presence of KOH or t-BuOK. The product, (S)-(-)-2-phenylethanol, was thus obtained with an optical yield of 67%. Covalent chloride rhodium complexes with the above ligands give rise to the same stereoisomer, whereas the opposite stereoselectivity is observed under catalysis by cationic trifluoromethanesulfonate rhodium(I) complexes. X-Ray phase analysis showed formation of nanosize particles in the precipitate of metallic rhodium.

Ruthenium(II) complexes of optically active P, N donor ligands. Synthesis and evaluation in the catalytic hydrogenation of acetophenone

Abstract The reaction of 2 equiv of the optically active P, N bidentate ligands 1–3 with RuCl(PPh 3 ) 3 gives the RuCl 2 (1–3) 2 (4–6) complexes in good yield as a mixture of isomers. The solid state structure of RuCl 2 ( 2 ) 2 (5c) is described: the two chlorine atoms are in trans position and due to steric crowding, one of the two ligands 2 is more weakly bound to Ru. The complexes 4–6 show moderate to good catalytic activity for the hydrogenation of acetophenone in basic media in hydrogen transfer conditions, from propanol-2, or under dihydrogen, but the enantiomeric excesses are low.

Catalytic Hydrogenation of Acetophenone Over Ruthenium Catalysts

Catalytic hydrogenation of acetophenone in ethanol was studied by using 5 wt.% Ru supported on active carbon, alumina, and titania. Parameters of kinetic equations (reaction rate constants and adsorption coefficients) were evaluated and the influence of the support on the reaction course was discussed. An enhanced selectivity of Ru/TiO2 towards carbonyl group hydrogenation with respect to the hydrogenation of the aromatic ring was confirmed.

Catalytic Hydrogenation of Acetophenone

The low pressure hydrogenation of acetophenone to 1-phenylethanol in the presence of some nickel and noble metal catalysts is described. The effects of each are noted. While palladium-on-carbon appears to be the catalyst of choice, others can be used under proper conditions. Only rhodium causes enough side reaction to discourage its use.