4730-22-7Relevant articles and documents
Tuning Nano-Nickel Catalyst Hydrogenation Aptitude by On-the-Fly Zirconium Doping
Zienkiewicz-Machnik, Ma?gorzata,Goszewska, Ilona,Giziński, Damian,?r?bowata, Anna,Kuzmowicz, Katarzyna,Kubas, Adam,Matus, Krzysztof,Lisovytskiy, Dmytro,Pisarek, Marcin,Jacinto
, p. 3132 - 3138 (2020)
The effect of nano-Ni catalyst post-synthetic Zr-modification on hydrogenation reaction of 6-methyl-5-hepten-2-one was investigated in a fixed bed continuous-flow micro-reactor to produce fine chemicals. The catalytic performance revealed that Zr-doping achieved by surface organometallic chemistry approach modifies the natural aptitude of nickel to hydrogenate C=C bond, since the addition of small quantities of zirconium significantly increased the amount of unsaturated and saturated alcohols formed in 6-methyl-5-hepten-2-one hydrogenation. Quantum chemical calculations revealed a stronger interaction between Zr←O=C that promotes the formation of C=C semihydrogenation product and enhances the probability of complete hydrogenation. The on-the-fly strategy presented herein enables for rapid optimization and understanding of catalytic processes.
Rh(III)Cp? and Ir(III)Cp? Complexes of 1-[(4-Methyl)phenyl]-3-[(2-methyl-4′-R)imidazol-1-yl]triazenide (R = t-Bu or H): Synthesis, Structure, and Catalytic Activity
Camarena-Diáz, Juan P.,Iglesias, Ana L.,Chávez, Daniel,Aguirre, Gerardo,Grotjahn, Douglas B.,Rheingold, Arnold L.,Parra-Hake, Miguel,Miranda-Soto, Valentín
, p. 844 - 851 (2019/02/19)
A series of iridium and rhodium complexes have been synthesized using as ligand a triazenide monofunctionalized with an imidazole substituent. Steric hindrance at the imidazole moiety induced differences in the coordination modes as well in the catalytic behavior of complexes 4-7. Complexes 4-7 were tested in the transfer hydrogenation of acetophenone and 5-alken-2-ones. The hydrogenation of either the double bond or the carbonyl group in 5-alken-2-ones, showed to be selective in the presence of 6, 7, and 10 and has a dependence on the presence or absence of base. Control experiments point out that the imidazole moiety in the structure of complexes 4-7 speeds-up the catalysis.
Phosphonate-Mediated Immobilization of Rhodium/Bipyridine Hydrogenation Catalysts
Forato, Florian,Belhboub, Anouar,Monot, Julien,Petit, Marc,Benoit, Roland,Sarou-Kanian, Vincent,Fayon, Franck,Jacquemin, Denis,Queffelec, Clémence,Bujoli, Bruno
, p. 2457 - 2465 (2018/02/06)
RhL2 complexes of phosphonate-derivatized 2,2′-bipyridine (bpy) ligands L were immobilized on titanium oxide particles generated in situ. Depending on the structure of the bipy ligand—number of tethers (1 or 2) to which the phosphonate end groups are attached and their location on the 2,2′-bipyridine backbone (4,4′-, 5,5′-, or 6,6′-positions)—the resulting supported catalysts showed comparable chemoselectivity but different kinetics for the hydrogenation of 6-methyl-5-hepten-2-one under hydrogen pressure. Characterization of the six supported catalysts suggested that the intrinsic geometry of each of the phosphonate-derivatized 2,2′-bipyridines leads to supported catalysts with different microstructures and different arrangements of the RhL2 species at the surface of the solid, which thereby affect their reactivity.
