Reductive Amination of Furanic Aldehydes in Aqueous Solution over Versatile Ni_<i>y</i>AlO_<i>x</i> Catalysts

Abstract

We disclose in this study a Ni6AlOx catalyst prepared by coprecipitation for the reductive amination of biomass-derived aldehydes and ketones in aqueous ammonia under mild reaction conditions. The catalyst exhibited 99% yield toward 5-aminomethyl-2-furylmethanol in the reaction of 5-hydroxymethyl furfural with ammonia at 100 °C for 6 h under 1 bar H2. The catalyst was further extended to the reductive amination of a library of aromatic and aliphatic aldehydes and ketones with a yield in the range 81–90% at optimized reaction conditions. Besides, 5-hydroxymethylfurfural could react with a library of primary and secondary amines with yields in the range 76–88%. The catalyst could be easily recycled and reused without apparent loss of activity in four consecutive runs.