Chemicals from Biomass: Chemoselective Reductive Amination of Ethyl Levulinate with Amines

Abstract

N-substituted-5-methyl-2-piyrrolidones have been obtained by reductive amination of ethyl levulinate with amines in presence of H 2 as reducing agent under solvent free conditions. The process involves as a first step the formation of an imine intermediate followed by hydrogenation of the imine group and subsequent cyclization into pyrrolidone. Pt/TiO 2 with Pt crystal faces decorated with TiOx is a very active and chemoselective catalyst, being possible to achieve high conversion and selectivity to the corresponding N-substituted-5-methyl-2-pyrrolidones even when other groups susceptible of hydrogenation such as vinyl, carbonyl or cyano groups are present in the amine moiety. A kinetic study showed that the reaction controlling step is the formation of the imine intermediate. The rate of formation is enhanced by the presence of protonic acid sites generated on the support by hydrogen dissociation on the metal resulting in a true bifunctional catalyst for the reaction.

Catalytic Transformation of Biomass Derivatives to Value‐Added Chemicals and Fuels in Continuous Flow Microreactors

“…[347] The amination of (biobased) acids (e. g., succinic acid, itaconic acid, LA or 3-HPA) can produce pyrrolidones that are widely used for the synthesis of polymers, dyes, surfactants, pharmaceuticals and agrochemicals. [348][349][350] These gas-liquid reductive aminations may benefit from operation in microreactors by overcoming gas-liquid mass transfer limitations and having well-regulated temperature distribution for an intensified and more selective product formation. [348][349][350] These gas-liquid reductive aminations may benefit from operation in microreactors by overcoming gas-liquid mass transfer limitations and having well-regulated temperature distribution for an intensified and more selective product formation.…”

Zirconium Oxide Supported Palladium Nanoparticles as a Highly Efficient Catalyst in the Hydrogenation–Amination of Levulinic Acid to Pyrrolidones

“…Based on these experimental data and the possible mechanism for LA conversion suggested previously, it is proposed that the hydrogenation–amination of LA to pyrrolidone comprises steps of (i) amination of LA to form imine, (ii) hydrogenation of imine to amine, and (iii) condensation of amine to pyrrolidone (Scheme ). In these steps, the formation of amine should be regarded as the rate‐limiting step because the order of the yields of the amine intermediate formed in the reaction is Pd/ZrO 2 >Pd/Al 2 O 3 >Pd/TiO 2 .…”

“…In particular, levulinic acid (LA), which could be obtained easily from lignocelluloses in an environmentally friendly way, has been recognized as one of the top 10 most promising platform molecules derived from biomass by the U.S. Department of Energy . Recently, many successful routes have been developed for the efficient transformation of LA to valuable chemicals . Particularly, the hydrogenation–amination of LA to pyrrolidones has attracted much attention because pyrrolidones are used widely as solvents and raw materials for the production of surfactants and fibers .…”

Transforming Methyl Levulinate into Biosurfactants and Biolubricants by Chemoselective Reductive Etherification with Fatty Alcohols

“…Through feasible catalytic or thermal processes, biomass can be easily converted into intermediate compounds called platform molecules for downstream synthesis of fuels and chemicals . Among them, levulinic acid (LA) or 4‐oxopentanoic acid has been classified by the US Department of Energy (DOE) as one of twelve promising platform molecules for the synthesis of several chemicals with multiple applications . LA can be obtained from lignocellulosic biomass that does not compete with food.…”