Selective Synthesis of Primary Amines from Nitriles under Hydrogenation Conditions

Abstract

The hydrogenation of aliphatic nitriles over Pd/C, Pd/Al2O3, and Pd−Au/Al2O3 catalysts were evaluated for the selective hydrogenation of aliphatic nitriles to the corresponding primary amines. The highest selectivity (>99%) toward primary amines was achieved when the reaction was carried out in acetic acid using 10 mol% of 25% Pd‐5% Au/Al2O3 under relatively low hydrogen pressure (0.8 MPa). Characterization of the catalysts by XRD, CO adsorption experiments, and EXAFS revealed that the excellent selectivity of 25% Pd‐5% Au/Al2O3 toward the synthesis of primary amines is determined by the electronic properties and/or the surface structure resulting from alloying Pd with Au.magnified image

Nitrogen‐Doped Carbon‐Supported Nickel Nanoparticles: A Robust Catalyst to Bridge the Hydrogenation of Nitriles and the Reductive Amination of Carbonyl Compounds for the Synthesis of Primary Amines

“…[1,2] Therefore, the development of new catalytic routes for the effective and sustainable synthesis of primary amines hasr eceived significant interest. In recentd ecades, several new catalytic methods have been documented for the synthesis of primary amines, such as the hydrogenationo fa mides, [3] hydrogenation of nitriles, [4,5] aminationo fa ryl halides, [6] reductivea mination of carbonyl compounds, [7] and direct amination of alcohols. [8] Although some of the reported methods have been effective for the synthesis of primary amines,i ti s still necessary to develop new routes for the efficient and selective production of primary amines under mild conditions.…”

Facile synthesis of supported Ru–Triphos catalysts for continuous flow application in selective nitrile reduction

“…† For selectivity enhancement towards the primary amine, both homogeneous and heterogeneous catalysts oen require the use of base additives. 13,[18][19][20]67,68 Remarkably, mild and additive-free conditions can be applied for this highly selective heterogeneous Ru-Triphos system similar to the homogeneous system of Beller and co-workers. 31 When screening the whole supported catalyst library at 100 C and 1.0 mol% catalyst loading, JJ-supported C 2 and PS-bound C 4 performed analogously compared to C 1 (Table 1, entries 4 and 6).…”

“…13,17 Milder reaction conditions can be applied when utilizing supported Pd catalysts, however, these are still reliant on acidic conditions to produce the terminal amines selectively. [18][19][20] On the other hand, there has been a growing interest to develop highly selective homogeneous catalysts for applications in nitrile reduction under very mild conditions. Most transition-metal complexes are based on precious metals featuring well-dened ligand structures, 17,21,22 but more recently also base metals 23,24 have been employed.…”

Selective Heterogeneous Catalytic Hydrogenation of Nitriles to Primary Amines

“…Among the precious metals, palladium is the most frequently used heterogeneous catalyst in the hydrogenation of nitriles, exclusively in supported form: on activated carbon [46][47][48][49][50][51][52][53], on alumina [51,52,[54][55][56][57][58][59][60][61][62], on MCM-41 [63] or on silica [64].…”

“…In 2018, Yoshimura et al [61] studied the hydrogenation of valeronitrile (17) to pentylamine (18a) over 10% Pd/C, 5% Pd/Al 2 O 3 , and 25% Pd-5% Au/Al 2 O 3 catalysts ( Table 7). The experiments were carried out in acetic acid, at 50 °C and 1.5 bar.…”