22023-64-9Relevant academic research and scientific papers
Transfer Hydrogenation of Nitriles, Olefins, and N-Heterocycles Catalyzed by an N-Heterocyclic Carbene-Supported Half-Sandwich Complex of Ruthenium
Mai, Van Hung,Nikonov, Georgii I.
, p. 943 - 949 (2016/05/09)
In the presence of KOBut, N-heterocyclic carbene-supported half-sandwich complex [Cp(IPr)Ru(pyr)2][PF6] (3) (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) catalyzes transfer hydrogenation (TH) of nitriles, activated N-heterocycles, olefins, and conjugated olefins in isopropanol at the catalyst loading of 0.5%. The TH of nitriles leads to imines, produced as a result of coupling of the initially formed amines with acetone (produced from isopropanol), and showed good chemoselectivity. Reduction of N-heterocycles occurs for activated polycyclic substrates (e.g., quinoline) and takes place exclusively in the heterocycle. The TH also works well for linear and cyclic olefins but fails for trisubstituted substrates. However, the C = C bond of α,β-unsaturated esters, amides, and acids is easily reduced even for trisubstituted species, such as isovaleriates. Mechanistic studies suggest that the active species in these catalytic reactions is the trihydride Cp(IPr)RuH3 (5), which can catalyze these reactions in the absence of any base. Kinetic studies are consistent with a classical inner sphere hydride-based mechanism of TH.
Optimum bifunctionality in a 2-(2-pyridyl-2-ol)-1,10-phenanthroline based ruthenium complex for transfer hydrogenation of ketones and nitriles: Impact of the number of 2-hydroxypyridine fragments
Paul, Bhaskar,Chakrabarti, Kaushik,Kundu, Sabuj
supporting information, p. 11162 - 11171 (2016/07/16)
Considerable differences in reactivity and selectivity for 2-hydroxypyridine (2-HP) derived ruthenium complexes in transfer hydrogenation are described. Bifunctional Ru(ii)-(phenpy-OH) [phenpy-OH: 2-(2-pyridyl-2-ol)-1,10-phenanthroline] complex (2) exhibited excellent catalytic activity in transfer hydrogenation (TH) of ketones and nitriles. Notably, in comparison with all the reported 2-hydroxypyridine (2-HP) derived ruthenium complexes in transfer hydrogenation, complex 2 displayed significantly higher activity. Additionally, exploiting the metal-ligand cooperativity in complex 2, chemoselective TH of ketones was achieved and sterically demanding ketones were readily reduced. An outer-sphere mechanism is proposed for this system as exogenous PPh3 has no significant effect on the rate of this reaction. This is a rare example of a highly active bifunctional Ru(ii) catalyst bearing only one 2-HP unit.
PHOTOCATALYTIC FORMATION OF SCHIFF BASES FROM PRIMARY AMINES BY PLATINIZED-TiO2 SUSPENSION IN ACETONITRILE
Ohtani, Bunsho,Osaki, Haruyoshi,Nishimoto, Sei-Ichi,Kagiya, Tsutomu
, p. 1075 - 1078 (2007/10/02)
Photoirradiation (λex>300nm) of platinized TiO2 suspended in Ar-purged acetonitrile solution of aliphatic and aromatic primary amines produced Schiff bases together with H2 and NH3 at room temperature.Solvent acetonitrile was partly reduced on the Pt site to inhibit the reduction of the Schiff bases into secondary amines.
ETUDE COMPARATIVE DE LA PHOTOREACTIVITE D'ENAMIDES ET DE THIOENAMIDS AROMATIQUES TERTIAIRES
Couture, A.,Dubiez, R.,Lablanche-Combier, A.
, p. 1835 - 1844 (2007/10/02)
Photolytic reactions of some simple aromatic enamides and thioenamides illustrate a novel example of the dramatic difference in the photochemical behaviour of carbonyl and thiocarbonyl compounds.In contrast with their oxo-analogues which are photoconverted into enaminoketones, thioenamides undergo photochemical cyclization to yield isoquinolinethione derivatives which can be easily convered into isoquinolones and tetrahydroisoquinolines.
