Chemicals from Biomass: Selective Synthesis of N-Substituted Furfuryl Amines by the One-Pot Direct Reductive Amination of Furanic Aldehydes

N-substituted furfuryl amines are an important class of compounds due to their pharmaceutical activities that can be produced by reductive amination of furfuraldehydes derived from biomass. With supported Pd nanoparticles it is possible to obtain high activities and selectivities for the production of secondary amines. CO adsorption monitored by IR shows the importance of the Pd crystal size and crystal face on catalyst activity and selectivity. When using Pd on carbon the amount of unsaturated Pd sites is very much enhanced with the corresponding increase in selectivity. The role of carbon deposition on metal terraces on catalytic selectivity is discussed. The optimized catalyst has been successfully applied in the reductive amination of 5-hydroxymethylfurfural with different amines and ammonia as well as in the one-pot reductive amination starting from nitrobenzene instead of aniline, giving the different N-substituted-5-(hydroxymethyl)-2-furfuryl amines with excellent activity and selectivity.