A Comprehensive Study on the Reductive Amination of 5‐Hydroxymethylfurfural into 2,5‐Bisaminomethylfuran over Raney Ni Through DFT Calculations

Abstract

Reductive amination of furfuryl alcohol, furfural and 5‐hydroxymethylfurfural (5‐HMF) were carried out on various metal catalysts. Over Raney Ni catalyst, we obtained the highest furfurylamine yields of 81.8 % and 94.0 % from furfuryl alcohol in absence and presence of H2, respectively. While furfural was used as the substrate, 100 % yield of furfurylamine could be achieved over Raney Ni under rather moderate conditions. Although 5‐HMF was completely converted over all catalysts used, the highest yield of 2,5‐bisaminomethylfuran (60.7 %) was obtained over Raney Ni at 160 °C in 12 h. The DFT calculations on the adsorption behavior of NH3 and H2 on different metal surfaces showed that the difference of the adsorption energy between NH3 and H2 on Ni is lower than those of other metals, indicating that less metal active sites on Ni surface is occupied by NH3, which leaves more active sites for dehydrogenation/hydrogenation reactions and in the end promotes the reductive amination reactions.

Highly selective and robust single-atom catalyst Ru1/NC for reductive amination of aldehydes/ketones

“…By contrast, hydrogen molecules can still be activated on the other three catalysts with measurable uptakes, and the adsorption strength and uptakes increase in the order of Ru 1 /NC-800 < Ru 1 /NC-900 < Ru 1 /NC-900-800NH 3 . This experimental result is consistent with the density functional theory (DFT) calculations reported by Zhou et al 54 , which reveals that the smaller the difference between the adsorption energy of NH 3 and H 2 is, the higher the activity for reductive amination is. Indeed, when the FAM yield is correlated with the RuN x structure, a similar increasing trend can be found as that of hydrogen adsorption heat (Fig.…”

Effective Oxidation of 5‐Hydroxymethylfurfural to 2,5‐Diformylfuran by an Acetal Protection Strategy

“…[24,[29][30][31] Partial oxidation of HMF can also lead to 2,5-diformylfuran (DFF), which can be further converted to 2,5bis(aminomethyl)furan (AMF). [32][33][34][35][36] Although AMF has substantial potential as a building block for polyamides, [37,38] efficient synthetic procedures have not yet been developed. For the first step of AMF production, we have studied aerobic oxidation of the hydroxymethyl group in HMF to the corresponding formyl group using supported metal catalysts and concentrated solutions (Scheme 1).…”

“…BHMTHF can be further transformed to aliphatic alcohols such as 1,6‐hexanediol and 1,2,6‐hexanetriol, and 1,6‐hexanediol is a source of adipic acid [24,29–31] . Partial oxidation of HMF can also lead to 2,5‐diformylfuran (DFF), which can be further converted to 2,5‐bis(aminomethyl)furan (AMF) [32–36] . Although AMF has substantial potential as a building block for polyamides, [37,38] efficient synthetic procedures have not yet been developed.…”

One‐Step Reductive Amination of 5‐Hydroxymethylfurfural into 2,5‐Bis(aminomethyl)furan over Raney Ni

“…[30] In conclusion, we initially studied stepwise reaction pathways from HMF to BAMF, in which the amination of C=O and CÀ OH depicted a similar pattern with our previous studies on the amination of furfural and furfuryl alcohol. [30,38] C=O in HMF can be catalyzed by a series of metals at a mild condition, especially Raney Co with a yield of 99.5 %. In contrast, the amination of CÀ OH is much harder.…”