(438d) Upgraded Bioelectrocatalytic N2 Fixation: From N2 to Chiral Amine Intermediates
AIChE Annual Meeting
Wednesday, November 13, 2019 - 8:54am to 9:12am
Enantiomerically pure chiral amines are of increasing value in the preparation of bioactive compounds, pharmaceuticals, and agrochemicals. Ï-transaminase (Ï-TA) is an ideal catalyst for the asymmetric amination as its excellent enantioselectivity and wide substrate scope. In order to shift the equilibrium of reactions catalyzed by Ï-TA to the side of amine product, an upgraded N2 fixation system based on bioelectrocatalysis was developed to realize the conversion from N2 to chiral amine intermediates. The produced NH3 was in situ reacted by L-alanine dehydrogenase to perform the alanine generation with NADH as a coenzyme. Ï-TA transferred the amino group from alanine to ketone substrates and finally produced desired chiral amine intermediates. The cathode of the upgraded N2 fixation system supplied enough reducing power to synchronously realize the regeneration of reduced methyl viologen (MV.+) and NADH for the nitrogenase and L-alanine dehydrogenase. The co-product, pyruvate, was consumed by L-alanine dehydrogenase to regenerate alanine and push the equilibrium to the side of amine. After 10 hours of reaction, the concentration of 1-methyl-3-phenylpropylamine achieved 0.54 mM with the 27.6% highest faradaic efficiency and >99% enantiomeric excess (eep). Due to the wide substrate scope and excellent enantioselectivity of Ï-TA, the upgraded N2 fixation system has great potential to produce a variety of chiral amine intermediates for pharmaceuticals and other applications.