Mechanistic Insight into Selective Deoxygenation of l-Lysine to Produce Biobased Amines

Abstract

The shift in consumer preference toward ecofriendly plastic products is driving the overall bioplastics and biopolymers market. As such, there is a strong demand for innovative processes that produce monomers from biomass feedstocks as an alternative to fossil resources. For instance, amino acids with two amino groups (e.g., L-lysine) are a unique biomass material that can be refined to produce diamines, which are further used to synthesize biobased nylons. Herein, we demonstrate that the diamine (cadaverine) was produced in a high yield from the second most-produced commercial amino acid (L-lysine). In the selective deoxygenation of lysine, the synergistic effect of the carbon-supported ruthenium catalyst and the phosphoric acid cocatalysts, the role of hydrogen gas, and the activation and suppression of the functional groups of lysine were elucidated in great detail. Under the optimum conditions, a 100% conversion of L-lysine and an ∼94% total yield of amines, with an ∼51% selectivity to diamines, were attained at 200 °C within 2 h. Moreover, both characterization and kinetic studies of the probe reactions were used to understand the reaction mechanism. The knowledge gained in this study may provide fundamental insights into the selective deoxygenation of other N-containing renewable feedstocks.

Sustainable access to renewable N-containing chemicals from reductive amination of biomass-derived platform compounds

“…Lysine, as the most abundant amino acid industrially produced from biomass fermentation, encompasses two amino groups showing great potential as a feedstock towards the production of nitrogen-containing compounds [216] [217]. Importantly, diamines with widely application in polyamides production could also be synthesized from lysine (Scheme 27b) [218]. A recent example of synthesis of diamine from lysine via deoxygenation was reported by Lin and co-workers using the combination of Ru/C and phosphoric acid, giving 100% lysine conversion with 51% yield of 1,5-diaminohexane at 200 °C with 2 h and 2.8 MPa of H 2 [218].…”

“…Importantly, diamines with widely application in polyamides production could also be synthesized from lysine (Scheme 27b) [218]. A recent example of synthesis of diamine from lysine via deoxygenation was reported by Lin and co-workers using the combination of Ru/C and phosphoric acid, giving 100% lysine conversion with 51% yield of 1,5-diaminohexane at 200 °C with 2 h and 2.8 MPa of H 2 [218]. mmol HCl for the conversion of chitin into N-acetyl glucosamine, affording 71.5% yield of N-acetyl glucosamine at 120 °C with 0.5 h (Scheme 28a) [221].…”

“…Scheme 27 (a) Synthesis of amines from decarboxylation of amino acids[215], (b) transformation of L-lysine into caprolactam or 1,5-diaminohexane[217,218] …”

Green chemical and biological synthesis of cadaverine: recent development and challenges

“…1C. 24 )COOH in the presence of H 3 PO 4 . It was consequently reduced to the reactive aldehyde intermediate which could produce cadaverine through deoxygenation catalyzed by Ru.…”

“…Chemical synthesis of cadaverine usually faces serious equipment corrosion, low target product selectivity, poor catalyst stability, and incapability of continuous and stable production. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] Most importantly, the petroleum-based raw material has a signicant impact on the environment. Synthesis of cadaverine through biocatalysis not only has good selectivity, but also can utilize renewable resources instead of fossil fuels, meeting the demand of the circular economy.…”