N,N′-Dialkylated 1,2-diamine derivatives as new efficient ligands for RuCl2(PPh3)3 catalyzed asymmetric transfer hydrogenation of aromatic ketones

Catalytic Hydrogenation of Arenes in Water Over In Situ Generated Ruthenium Nanoparticles Immobilized on Carbon

“…These results showed that it is not just the Ru metal but also the overall structure of the components of [( η 6 ‐benzene)Ru(en)Cl]PF 6 that play a crucial role in the observed high catalytic activity towards 1 . Notably, in transfer hydrogenation catalysts, ligands that have N−H bonds play a determining role particularly to help in the activation of the H source . It is evident from previous studies that among the Ru‐based catalysts explored for HCOOH to H 2 conversion or hydrogenation using HCOOH, the most active catalysts are those that have N‐based ligands .…”

“…have reported the selective hydrogenation of the aromatic ring of ketones and phenols using cyclic(amino)alkyl carbene rhodium complexes under H 2 (5 bar) . Notably, ruthenium arene complexes based on N‐donor ligands, such as ethylenediamine‐derived ligands have been identified as transfer hydrogenation catalysts, and therefore, we anticipated that these complexes could be used to achieve arene ring hydrogenation under precisely tuned reaction conditions. The reaction of the precursor, a ruthenium arene dimer, with ethylenediamine (en) in a suitable solvent led to the straightforward synthesis of cationic [( η 6 ‐arene)Ru(en)Cl] + complex .…”

“…have also explored analogous complexes for the enantioselective hydrogenation of naphthalene derivatives in the presence of H 2 gas . Notably, these and plenty of other transfer hydrogenation/hydrogenation reactions catalysed by (arene)Ru‐en‐based complexes target mainly C=O or C=N bonds . However, at an elevated temperature (60–100 °C) using high‐pressure H 2 gas (10–60 bar), the hydrogenation of C=C bonds (aromatic and others) catalysed by Ru complexes was also successful …”

“…Our experimentali nvestigations evidencedt hat the observed enhanced activity for arene hydrogenation was driven by the unique structural advantages of the organometallicp recursor to activate formic acid, in which the presence of an itrogen ligand is crucial to achieve ah igh catalytic activity.T EM analysis revealed the formation of Ru 0 nanoparticles, and Hg 0 poisoning experiments support the heterogeneous nature of the active catalyst. donor ligands, such as ethylenediamine-derived ligandsh ave been identified as transfer hydrogenation catalysts, [38][39][40][41][42] and therefore, we anticipated that these complexesc ould be used to achieve arene ring hydrogenation under precisely tuned reaction conditions. The reactiono ft he precursor, ar uthenium arene dimer,w ith ethylenediamine (en) in as uitable solvent led to the straightforward synthesis of cationic [(h 6 -arene)Ru(en)Cl] + + complex.…”

Asymmetric transfer hydrogenation of aromatic ketones by Rh(I)/bimorpholine complexes

“…Many catalytic systems provide a high conversion and enantioselectivity at room temperature, while some catalysts show a high activity only at increased temperatures (80°C). 9,16,23 However, some catalysts operate successfully even at À30°C. 8 We studied the influence of the reaction temperature on the reduction of ketones 2, 5 and 7 (Table 4).…”