An Efficient Hydrogenation of Dinitrile to Aminonitrile in Supercritical Carbon Dioxide

Recent Advances in Catalytic Systems for the Reduction of Aromatic and Aliphatic Nitrile Compounds to Amines

Amines are important and valuable compounds widely used in the chemical industry to produce various products such as dyes, detergents, solvents, additives, pharmaceutical products, and anti-foam agents. A property that distinguishes primary amines from other compounds is their straightforward functionalization. Therefore, the synthesis of different amine compounds has been considered by many researchers in recent years. Usually,.primary amines are produced via amination of alcohols, reductive amination, and reduction of nitro and amide compounds. Furthermore, a useful and atom-economical method for producing primary amines is reducing nitrile compounds using catalytic systems. Traditionally, nitriles are reduced using metal hydrides such as LiAlH4 or NaBH4. These methods have important restrictions in terms of selectivity and waste generation. Hence, the heterogeneous and homogeneous catalysts were investigated for the hydrogenation of nitriles to diverse amines. This review describes the performance of different catalytic systems for reducing nitrile compounds to their corresponding amines.

General Construction of Amine via Reduction of N=X (X = C, O, H) Bonds Mediated by Supported Nickel Boride Nanoclusters

Amines play an important role in synthesizing drugs, pesticides, dyes, etc. Herein, we report on an efficient catalyst for the general construction of amine mediated by nickel boride nanoclusters supported by a TS-1 molecular sieve. Efficient production of amines was achieved via catalytic hydrogenation of N=X (X = C, O, H) bonds. In addition, the catalyst maintains excellent performance upon recycling. Compared with the previous reports, the high activity, simple preparation and reusability of the Ni-B catalyst in this work make it promising for industrial application in the production of amines.

Modulated electronic structure of Pd nanoparticles on Mg(OH)2 for selective benzonitrile hydrogenation into benzylamine at a low temperature

Pd nanoparticles with enriched electronic density anchored on Mg(OH)2 realize selective benzonitrile hydrogenation to benzylamine at low temperature in the absence of additives, in an atom-economical and green approach for synthesis of highly value-added primary amines.

A cobalt phosphide catalyst for the hydrogenation of nitriles

A well-defined nano-cobalt phosphide serves as an air-stable, highly active and reusable heterogeneous catalyst for the selective hydrogenation of nitriles to primary amines under mild reaction conditions.

The study of metal phosphide catalysts for organic synthesis is rare. We present, for the first time, a well-defined nano-cobalt phosphide (nano-Co₂P) that can serve as a new class of catalysts for the hydrogenation of nitriles to primary amines. While earth-abundant metal catalysts for nitrile hydrogenation generally suffer from air-instability (pyrophoricity), low activity and the need for harsh reaction conditions, nano-Co₂P shows both air-stability and remarkably high activity for the hydrogenation of valeronitrile with an excellent turnover number exceeding 58000, which is over 20- to 500-fold greater than that of those previously reported. Moreover, nano-Co₂P efficiently promotes the hydrogenation of a wide range of nitriles, which include di- and tetra-nitriles, to the corresponding primary amines even under just 1 bar of H₂ pressure, far milder than the conventional reaction conditions. Detailed spectroscopic studies reveal that the high performance of nano-Co₂P is attributed to its air-stable metallic nature and the increase of the d-electron density of Co near the Fermi level by the phosphidation of Co, which thus leads to the accelerated activation of both nitrile and H₂. Such a phosphidation provides a promising method for the design of an advanced catalyst with high activity and stability in highly efficient and environmentally benign hydrogenations.

Formation and nitrile hydrogenation performance of Ru nanoparticles on a K-doped Al2O3 surface

Decarbonylation-promoted Ru nanoparticle formation from Ru₃(CO)₁₂ on a basic K-doped Al₂O₃ surface was investigated by in situ FT-IR and in situ XAFS. The prepared Ru nanoparticle acted as an efficient catalyst for nitrile hydrogenation to primary amine.

Mild and selective hydrogenation of aromatic and aliphatic (di)nitriles with a well-defined iron pincer complex

The catalytic hydrogenation of carboxylic acid derivatives represents an atom-efficient and clean reduction methodology in organic chemistry. More specifically, the selective hydrogenation of nitriles offers the possibility for a green synthesis of valuable primary amines. So far, this transformation lacks of useful, broadly applicable non-noble metal-based catalyst systems. In the present study, we describe a molecular-defined iron complex, which allows for the hydrogenation of aryl, alkyl, heterocyclic nitriles and dinitriles. By using an iron PNP pincer complex, we achieve very good functional group tolerance. Ester, ether, acetamido as well as amino substituents are not reduced in the presence of nitriles. Moreover, nitriles including an α,β-unsaturated double bond and halogenated derivatives are well tolerated in this reaction. Notably, our complex constitutes the first example of an homogeneous catalyst, which permits the selective hydrogenation of industrially important adipodinitrile to 1,6-hexamethylenediamine.