Synthesis ofn-Butylamine from Butyronitrile on Ni/SiO₂: Effect of Solvent

Selective Heterogeneous Catalytic Hydrogenation of Nitriles to Primary Amines

“…In an attempt to reduce the formation of by-products, Ni/SiO 2 , Co/SiO 2 , Ru/SiO 2 (the latter two will be discussed in Sections 2.2 and 3.2) catalysts were tested to optimize the reaction conditions (solvents, temperature, pressure). The highest selectivity to butylamine (84%) was achieved in ethanol ( Table 2, entry 1), while using benzene, toluene or cyclohexane the primary amine selectivity significantly decreased to 63-39% ( Table 2, entries 2-4) [28]. These results suggest that using a protic solvent influences the strength of the solvent-butylamine interaction in the liquid phase, which positively affects the selectivity of primary amine over Ni/SiO 2 .…”

“…Nickel is a typically applied catalyst in the hydrogenation of nitriles in different forms, such as Raney-type one [10-14, 16-18, 24, 25], supported on silica [7,[26][27][28][29][30], alumina [31][32][33][34] or sepiolite [35], as well as NiAl alloy [36], Ni nanoparticles [37][38][39] or Ni 2 P [40].…”

Chemoselective hydrogenation of unsaturated nitriles to unsaturated primary amines: Conversion of cinnamonitrile on metal-supported catalysts

“…Previous works have reported that C C bonds are more reactive to hydrogenation than the nitrile groups [4,5] and therefore selective C≡N hydrogenation in presence of double bonds is difficult to achieve, in particular when both unsaturated groups are conjugated or in close proximity [6]. Most of the few papers dealing with the hydrogenation of unsaturated nitriles on solid catalysts have been carried out on Ni and Co-based catalysts [4,5,7,8], probably because both metals are highly active and selective to obtain saturated primary amines from the corresponding saturated nitrile [9][10][11]. However, in the case of unsaturated nitriles, Raney Ni and Co catalysts promote the preferential hydrogenation to the corresponding saturated nitrile rather than to the unsaturated primary amine [3].…”

Effect of the catalyst preparation method on the performance of Ni-supported catalysts for the synthesis of saturated amines from nitrile hydrogenation

“…However, the reaction selectivity also depends on other parameters such as the support acid/base properties, the solvent nature and the catalyst preparation method. In previous works, we have thoroughly studied the effect of solvent on nitrile hydrogenation selectivity and activity using metal-supported catalysts [12][13][14]. The influence of support acidity on catalyst selectivity has also been investigated, but while some authors propose that the surface acidity favors the condensation reactions and is detrimental for the formation of primary amines [15,16], others suggest that acidity has no influence on the reaction selectivity [17].…”