Reductive Amination Of Levulinic Acid Research Articles

Reductive amination of levulinic acid to different pyrrolidones on Ir/SiO2-SO3H: Elucidation of reaction mechanism

Levulinic acid (LA) transformation to different pyrrolidones via reductive amination was studied using an Ir/SiO2-SO3H catalyst in liquid phase. The effects of solvent, amine concentration, H2 partial pressure, catalyst mass, and reuse were studied. The spent catalysts were evaluated by DRIFTS to obtain evidence of the interaction of levulinic acid with aniline on the catalyst surface. The sulfonic groups on SiO2 improved the yield to pyrrolidones and avoided side reactions. A reaction mechanism is proposed where the reductive amination occurs between LA and amine towards an intermediate amine that is then cycled. The Gibbs free energy for the reaction mechanism was evaluated. Besides, the HOMO and LUMO of the amine reactants and intermediates using density functional theory (DFT) with the B3LYP-D3 method were theoretically determined to understand the rate-limiting and the cyclization steps.

Highly Stable Porous-Carbon-Coated Ni Catalysts for the Reductive Amination of Levulinic Acid via an Unconventional Pathway

The catalytic conversions of biomass and its derivatives into fuels and chemicals require active and stable catalysts. Non-noble-metal catalysts typically suffer from deactivation due to the leaching and sintering of the metal species in liquid-phase reactions. In this work, we report a facile synthesis of porous-carbon-coated Ni catalysts supported on carbon nanotubes (CNFx@Ni@CNTs) by atomic layer deposition for the reductive amination of levulinic acid (LA) with amines to pyrrolidones. Under the protection of porous carbon with a moderate thickness, the optimized CNF30@Ni@CNTs catalyst showed a 99% yield of pyrrolidones and recyclability of up to 20 runs without the leaching and sintering of Ni nanoparticles. On the basis of verification experiments and density functional theory calculations, we determined that our Ni-catalyzed reductive amination of LA with amines underwent an unconventional pathway via amides as the first intermediate, followed by tandem cyclization, intramolecular dehydration, and h...

Iridium‐Catalyzed Reductive Amination of Levulinic Acid to Pyrrolidinones under H2 in Water

AbstractThe synthesis of pyrrolidinones from reductive amination of levulinic acid (LA) with primary amines is reported. Pyrrolidinones have various applications such as surfactants, pharmaceutical intermediates, dispersants, and solvents. The half‐sandwich Cp*Ir complex (Cp* is 1,2,3,4,5‐pentamethylcyclopenta‐1,3‐diene) coordinated by bipyridine ligand bearing both dimethylamino and ortho‐hydroxyl groups showed high catalytic activity for the reductive amination of LA. A range of primary amines, such as aromatic and benzyl amines, were readily converted to corresponding pyrrolidinones in good yields.

NHC-based coordination polymers as solid molecular catalysts for reductive amination of biomass levulinic acid

Novel NHC-Ru coordination polymer acts as a high activity solid molecular catalyst in the solvent-free reductive aminations of levulinic acid. Besides the catalyst could be reused for 37 runs, up to 6.7 × 104 TON could be achieved.

Synthesis of pyrrolidones and quinolines from the known biomass feedstock levulinic acid and amines

The catalytic conversion of biomass-derived compounds into value-added products such as food additives, agrochemical components, and pharmaceutical formulations, is a promising and cost effective synthetic strategy. Here, we describe the synthesis of a variety of N-(alkyl, aryl)-5-methyl-2-pyrrolidones through the reductive amination of levulinic acid using formic acid as the hydrogen source. This system is catalyzed by 3.8nm ruthenium nanoparticles that were prepared by thermal decomposition of [Ru3(CO)12] in solvent-free conditions. When the reactions were carried out without the catalyst, the pyrrolidones were obtained with low yield and poor selectivity. In addition, the reaction between levulinic acid and 2-ethynylaniline produced 2-(2,4-dimethylquinolin-3-yl) acetic acid (8) in mild and metal-free conditions with good yield. Furthermore, the synthesis of substituted quinolines was achieved through a condensation reaction between levulinic acid and different 2-alkynylanilines promoted by p-toluenesulfonic acid, this method is highlighted as a novel procedure for the preparation of quinolines.

Heterogeneous Pt Catalysts for Reductive Amination of Levulinic Acid to Pyrrolidones

Supported platinum catalysts have been studied for the reductive amination of levulinic acid (LA) by H2 to N-alkyl-5-methyl-2-pyrrolidones under solvent-free conditions. The activity depends on the type of metal (Pt, Re, Pd, Rh, Ru, Cu, Ni), support material, and coloaded oxides of transition metals (V, Cr, Mo, W, Re). In 24 kinds of catalyst tested, Pt and MoOX (molybdenum oxide) coloaded TiO2 (Pt-MoOX/TiO2) shows the highest activity. Pt-MoOX/TiO2 is effective for reductive amination of LA with wide varieties of amines under mild conditions (3 bar of H2, 100 °C, solvent-free) to give high isolated yield of pyrrolidinones and shows higher turnover number (TON) than previously reported catalysts for reductive amination of LA with an aliphatic amine. The catalyst can be separated from the reaction mixture by filtration, and the recovered catalyst can be reused. This is the first general and reusable heterogeneous catalytic system for the reductive amination of LA. On the basis of mechanistic studies, high ...

Ruthenium‐Catalyzed Conversion of Levulinic Acid to Pyrrolidines by Reductive Amination

Combo deal: An aqueous solution of levulinic acid (LA) and formic acid (FA) derived from biomass-based carbohydrates can be converted efficiently to pyrrolidines via a ruthenium catalyst without need for an energy-intensive separation of LA or an external H2 source. The ruthenium catalyst combines two processes: decomposition of FA to H2 and reductive amination of LA with an amine. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.