Ruthenium nanoparticles supported on magnesium oxide: A versatile and recyclable dual-site catalyst for hydrogenation of mono- and poly-cyclic arenes, N-heteroaromatics, and S-heteroaromatics

A polymer supported palladium(II) β-ketoesterate complex as active and recyclable pre-catalyst for selective reduction of quinolines in water with sodium borohydride

“…On the contrary, in the presence of Pd-pol, the dihydrogen (formed according to the reaction reported in Scheme 3) may add to the C N double bond of the 8-methylquinoline, following an ionic pathway involving solvent assisted heterolytic hydrogen activation promoted by the basic substrate (Scheme 5). As already substantiated in similar cases [22,71], this would result in protonation of the 8-methylquinoline, followed by H-transfer from the metal to the adjacent carbon atom, as also suggested by Dobereiner et al [8] and by Sánchez-Delgado and co-workers [72,73].…”

Unsupported nanoporous palladium-catalyzed chemoselective hydrogenation of quinolines: Heterolytic cleavage of H2 molecule

“…This process is the most convenient and promising technique to produce py-THQs, because of its high atom utilization and the easy availability of the raw material [10]. Many types of homogeneous [11][12][13][14][15][16][17][18][19] and heterogeneous [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] catalyst systems have been developed for the chemoselective hydrogenation of quinolines. Although heterogeneous catalyst systems have recently attracted considerable attention and are successfully employed in the chemoselective hydrogenation of quinolines (Scheme 1), relatively high H2 pressures (10-50 atm) and high reaction temperatures (60-150 °C) are required.…”

Gold Particles Supported on Amino‐Functionalized Silica Catalyze Transfer Hydrogenation of N‐Heterocyclic Compounds

“…The reported heterogeneous catalytic systems include catalysts based on Ru (supported on SiO 2 , hectorite, glucose‐derived carbon spheres, poly(4‐vinylpyridine), MgO, and Ru−Cu nanocages and nanocrystals), Rh (on Al 2 O 3 , ionic liquid, various metal oxides, MgO, and PEG), Pd (on hydroxyapatite, methacrylic polymer; tannin‐ and metal‐carbon stabilized), Pt (unsupported, on various metal oxides), Co (on nitrogen‐dopedgraphene), and Au (unsupported nanoporous, on TiO 2 support). The reductions have been performed with pressurized gaseous hydrogen in most cases . On the other hand, transfer hydrogenation reactions employing hydrogen donors such as PhMe 2 SiH/H 2 O, PhMe 2 SiH/EtOH, and HCOOH/triethylamine are often preferred owing to the use of simple reactors, without the need of hazardous gaseous hydrogen.…”

“…On the other hand, transfer hydrogenation reactions employing hydrogen donors such as PhMe 2 SiH/H 2 O, PhMe 2 SiH/EtOH, and HCOOH/triethylamine are often preferred owing to the use of simple reactors, without the need of hazardous gaseous hydrogen. The scope of unsaturated N‐heterocycles that were reduced in the aforementioned studies comprises for instance derivatives of quinoline isoquinoline, quinoxaline, acridine, and phenanthroline …”