Chemoselective hydrogenation of nitriles to secondary or tertiary amines catalyzed by aqueous‐phase catalysts supported on hexagonal mesoporous silica

Abstract

The first supported aqueous-phase catalyst for the hydrogenation of nitriles is revealed. The catalyst prepared from Pd(PhCN) 2 Cl 2 , water-soluble ligand 2,2′-biquinoline-4,4′-dicarboxylic acid dipotassium salt and mesoporous silica is a highly efficient catalyst for the selective formation of secondary or tertiary amines from aromatic or aliphatic nitriles. The catalytic system is stable and can be recycled and reused three times without loss of activity and selectivity.This environmentally friendly process is, in addition, an attractive alternative to many homogeneous and heterogeneous catalysts because of its easy preparation and the moderate operational conditions under which it is highly active.

Selective Construction of a Biomass-Based Secondary Amine by Hydrogenative Homocoupling of Nitrile Using an Iridium Complex in a Metal–Organic Framework

“…For example, benzylamine, dibenzylamine, tribenzylamine, N -benzylidenebenzylamine (secondary imine), and toluene were observed from the catalytic hydrogenation of benzonitrile under H 2 . Meanwhile, selective hydrogenative homocoupling of benzonitrile with H 2 to afford dibenzylamine was achieved with well-designed catalysts of Pd, , Pd-Ni, Pd-Pt, Pd-NiO, Ru, Rh, and Ni . As a non-noble metal, the Ni-based catalyst was also reported for the hydrogenative homocoupling of benzonitrile; however, its moisture- and air-sensitive nature significantly inhibited its potential application.…”

Ligand–metal cooperativity in quinonoid based nickel(ii) and cobalt(ii) complexes for catalytic hydrosilylative reduction of nitriles to amines: electron transfer and mechanistic insight

“…Although hydrogenation of nitriles to amines is an industrially attractive atom-efficient process and several catalytic systems have also been developed for this transformation, these hydrogenation methods suffer from harsh reaction conditions, low functional group tolerance, and poor selectivity due to the uncontrolled reactivity of intermediate imines, leading to undesired product formation. [22][23][24][25][26][27][28][29] In contrast, catalytic hydrosilylation of nitriles using various hydrosilanes has received considerable attention because of their operational simplicity, and the possibility of choosing silanes based on their reactivity and mild reaction conditions. These are essential to improve the chemo-and regioselectivity of an organic transformation reaction.…”