Synthesis of amines from nitrile hydrogenation on Co/SiO2. Effect of the substrate structure

MILTON AGÜERO; DARÍO J. SEGOBIA; ANDRÉS F. TRASARTI

Santa Fe

Workshop; French-Argentinian Workshop on Heterogeneous Catalysis; 2023

CONICET-CNRS-UNL-Institut de Chimie des Millieux et Matériaux de Poitiers

Nitrogen compounds, and particularly amines, constitute one of the fundamental bases of life, many neurotransmitters, alkaloids and other active biomolecules are nitrogen compounds. A convenient route for amines production is the hydrogenation of nitriles, due to availability of reagents, low price and atomic efficiency high. This reaction proceeds through hydrogenation/condensation consecutive reactions leading to the formation of a mixture of primary, secondary and tertiary amines. Frequently, a high selectivity to a particular amine is wanted in order to eliminate the cost of product separation process. Increasing research efforts have been devoted to selectively convert saturated nitriles to a given saturated primary (PA), secondary (SA) or tertiary amine (TA). Figure 1 shows the reaction network of nitrile hydrogenation according to currently accepted reaction pathways. There is a general agreement that on metal-supported catalysts the reaction selectivity depends mainly on the nature of the metal component [1], however, operating conditions, catalyst preparation method and the solvent nature have also an important influence on the reaction activity and selectivity. There are very few studies that investigate the effect of the nitrile structure on the reaction activity and selectivity. In the present work we study the effect of the nitrile structure on the reaction activity and selectivity in solvents of different nature. We discuss the hydrogenation in liquid phase aliphatic (acetonitrile, AN, butyronitrile, BN, isobutyronitrile, IBN) and aromatic nitriles (benzonitrile, BeN and benzyl cyanide, BC) on Co/SiO2, using solvents of different chemical nature.