14572-89-5Relevant articles and documents
Selective Hydrogenation by Carbocatalyst: The Role of Radicals
Ahmad, Muhammad Sohail,He, Huixin,Nishina, Yuta
, p. 8164 - 8168 (2019)
The selective hydrogenation of the nitro moiety is a difficult task in the presence of other reducible functional groups such as alkenes or alkynes. We show that the carbon-based (metal-free) catalyst can be used to selectively reduce substituted nitro groups using H2 as a reducing agent, providing a great potential to replace noble-metal catalysts and contributing to simple and greener strategies for organic synthesis.
[N,P]-pyrrole-phosphine ligand: An efficient and robust ligand for Ru-catalyzed transfer hydrogenation microwave-assisted reactions
Sánchez-Rodríguez,Fragoso-Medina,Ramírez-Meneses,Gouygou,Ortega-Alfaro,López-Cortés
, p. 49 - 54 (2018)
A pyrrolyl-containing [N-P]-ligand (L1) and [Ru] were evaluated as catalytic system in transfer hydrogenation reaction of ketones. A comparison between microwave irradiation vs conventional heating conditions indicates that MW can be successfully used as energy source, improving the reaction time. The L1/Ru(II) proved to be an active, efficient and robust catalytic system. The scope of this catalytic system was evaluated using a diversity of substrates that include electron-withdrawing and electron-donor groups achieving a range of 65 to 95% conversion. Moreover, the catalytic system showed good activity even with highly sterically hindered ketones.
Synthesis and characterization of silica-coated magnetite nanoparticles modified with bis(pyrazolyl) triazine ruthenium(II) complex and the application of these nanoparticles as a highly efficient catalyst for the hydrogen transfer reduction of ketones
Mobinikhaledi, Akbar,Moghanian, Hassan,Ajerloo, Bahram,Dousti, Fatemeh
, (2020)
We present a facile and efficient method for modifying the surface of silica-coated Fe3O4 magnetic nanoparticles (MNPs) with bis(pyrazolyl) triazine ruthenium(II) complex [MNPs@BPT–Ru (II)]. Field emission-scanning electron microscopy, thermogravimetric/derivative thermogravimetry analysis, X-ray powder diffraction, Fourier-transform infrared spectroscopy, vibrating sample magnetometry, and energy-dispersive X-ray spectrometry analyses were employed for characterizing the structure of these nanoparticles. MNPs@BPT–Ru(II) nanoparticles proved to be a magnetic, reusable, and heterogeneous catalyst for the hydrogen transfer reduction of ketone derivatives. In addition, highly pure products were obtained with excellent yields in relatively short times in the presence of this catalyst. A comparison of this catalyst with those previously used for the hydrogen transfer reactions proved the uniqueness of MNPs@BPT–Ru(II) nanoparticle which is due to its inherent magnetic properties and large surface area. The presented method also had other advantages such as simple reaction conditions, eco-friendliness, high recovery ability, easy work-up, and low cost.
Hydrogenation of 4-nitroacetophenone over Rh/silica
Currall, Kathryn,Jackson, S. David
, p. 59 - 63 (2014)
The hydrogenation of 4-nitroacetophenone (4-NAP) and 4-aminoacetophenone (4-AAP) was examined over rhodium/silica catalysts. The reactions were carried out using isopropanol as the solvent under a range of temperatures (303-333 K) and pressures (1-5 barg). An activation energy of 50 ± 4 kJ mol -1 was determined for 4-NAP hydrogenation and 48 ± 2 kJ mol-1 for 4-AAP hydrogenation. Orders of reaction were obtained for 4-NAP (zero order) and hydrogen (first order) and a kinetic isotope effect of 3.0 was observed for 4-NAP hydrogenation and ～1.4 for 4-AAP hydrogenation when deuterium was used. Under specific conditions high yields (～94%) to 4-aminoacetophenone and 1-(4-aminophenyl) ethanol could be obtained from 4-NAP hydrogenation. An antipathetic metal crystallite particle size effect was observed for both reactants.
Optimizing selective partial hydrogenations of 4-nitroacetophenone via parallel reaction screening
Hawkins, Joel M.,Makowski, Teresa W.
, p. 328 - 330 (2001)
The hydrogenation of 4-nitroacetophenone was optimized for selective reduction to the corresponding aniline-ketone (97%), aniline-alcohol (95%), and aniline-methylene (99%) as a case study demonstrating the optimization of the selective reduction of a polyfunctional substrate using a parallel pressure reactor. The catalyst, catalyst loading, pressure, temperature, and methanesulfonic acid stoichiometry were varied, first in an initial coarse screen (catalyst and acid stoichiometry), and then in a full factorial screen for selected catalysts. Facile profiling of hydrogen uptake in each reaction aided setting reaction time and parameter ranges for the full factorial analysis, allowed for quickly spotting under-and overreduction, aided predicting robust reaction endpoints, and provided data for analyzing kinetic behavior.
Manganese-Catalyzed Hydrogenation of Ketones under Mild and Base-free Conditions
Brünig, Julian,Kirchner, Karl,Veiros, Luis F.,Weber, Stefan
supporting information, p. 1388 - 1394 (2021/05/31)
In this paper, several Mn(I) complexes were applied as catalysts for the homogeneous hydrogenation of ketones. The most active precatalyst is the bench-stable alkyl bisphosphine Mn(I) complex fac-[Mn(dippe) (CO)3(CH2CH2CH3)]. The reaction proceeds at room temperature under base-free conditions with a catalyst loading of 3 mol % and a hydrogen pressure of 10 bar. A temperature-dependent selectivity for the reduction of α,β-unsaturated carbonyls was observed. At room temperature, the carbonyl group was selectively hydrogenated, while the C=C bond stayed intact. At 60 °C, fully saturated systems were obtained. A plausible mechanism based on DFT calculations which involves an inner-sphere hydride transfer is proposed.
Ruthenium complex based on [N,N,O] tridentate -2-ferrocenyl-2-thiazoline ligand for catalytic transfer hydrogenation
Badillo-Gómez,Sánchez-Rodríguez,Toscano,Gouygou,Ortega-Alfaro,López-Cortés
, (2020/12/14)
A method for the synthesis of a new phosphine-free [N,N,O]-tridentate Schiff base ligand L1 using the 2-Ferrocenyl-2-thiazoline as scaffold was developed. The 1,2-disubstituted ferrocene-based ligand was assembled using as key strategy the directed ortho-metalation (DoM) in 2-ferrocenyl-2-thiazoline. L1 was successfully obtained in 83% of overall yield after two-step synthesis. The coordination ability of L1 towards Ru(II) was evidenced and the resulting complex was characterized by IR, UV-vis and EPR. Its catalytic performance was tested in transfer hydrogenation of a variety of substrates giving moderate to excellent conversions.
Highly selective hydrogenation of aromatic ketones to alcohols in water: effect of PdO and ZrO2
Alsalahi, W.,Trzeciak, A. M.,Tylus, W.
, p. 10386 - 10393 (2021/08/09)
Pd/ZrO2and PdO/ZrO2composites, containing Pd or PdO nanoparticles, were prepared using an original one-step methodology. These nanocomposites catalyze the hydrogenation of acetophenone (AP) at 1 bar and 10 bar of H2in an aqueous solution. Compared to unsupported Pd or PdO nanoparticles, a remarkable increase in their activity was achieved as a result of interaction with zirconia. An unsupported PdO hydrogenated AP mainly to ethylbenzene (EB), while excellent regioselectivity towards 1-phenylethanol (PE) was obtained with PdO/ZrO2and it was preserved during recycling. Similarly, regioselectivity to PE was higher with Pd/ZrO2compared to unsupported Pd NPs. PdO and zirconia resulted in high selectivity to alcohols in the hydrogenation of substituted acetophenones.
