Recyclable Earth‐Abundant Metal Nanoparticle Catalysts for Selective Transfer Hydrogenation of Levulinic Acid to Produce γ‐Valerolactone

Abstract

Nanoparticles (NPs) derived from earth-abundant metal(0) carbonyls catalyze conversion of bio-derived levulinic acid into γ-valerolactone in up to 93% isolated yield. This sustainable and green route uses non-precious metal catalysts and can be performed in aqueous or ethanol solution without using hydrogen gas as the hydrogen source. Generation of metal NPs using microwave irradiation greatly enhances the rate of the conversion, enables the use of ethanol as both solvent and hydrogen source without forming the undesired ethyl levulinate, and affords recyclable polymer-stabilized NPs.

Efficient Hydrogenation of Biomass Oxoacids to Lactones by Using NHC–Iridium Coordination Polymers as Solid Molecular Catalysts

“…No better outcomes were found. Furthermore, organic bases including 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), Et 3 Na nd pyridine all resulted in unsatisfactory yields (Table 1, entries 4a nd 5, and Ta ble S1, entries [13][14][15][16][17][18][19]. Decreasing the reaction time, temperature or the pressure of H 2 led to inferior results( Ta ble 1, entries 6, 7a nd Ta ble S1,entries 20-21).…”

“…[11] Among them, the hydrogenation of biomass levulinic acid (LA) and its derivatives followed by cyclization constituteo ne of the most attractive and effective approaches to access GVL. Until now,m ultiple heterogeneous [12][13][14][15][16][17][18] and homogenous [19][20][21][22][23][24][25] catalysts have been developeda nd investigated.I ng eneral, heterogeneous catalysts offer severalp rominent advantages including easy separation and possible reusability of the catalysts. [13,14] However,d ue to their low activities, high reactiont emperatures and H 2 pressures are required to achieves atisfactory outcomes.…”

Regioselective Hydrogenation of Itaconic Acid to γ‐Isovalerolactone by Transition‐Metal Nanoparticle Catalysts

“…First, the control reaction with H 2 [1000 psi (6895 kPa), 190 8C, 36 h] insteado f syngas (2 H 2 /CO) afforded am ixture of four products containing a MGBL,G iVL, 2-methyl-4-hydroxybutanoic acid (2-MHBA), and 3-MHBA( Figure S3 in the SupportingI nformation), highlightingt he important role of CO in the regioselectivity of this hydrogenation. Fourth, subjecting the independently synthesized methyl-4-hydroxy-3methylbutanoate ( Figure In situ-generated TM-NPs were shown to be responsible for the conversion of LA to GVL [22] andt he conversion of glucose to 5-hydroxymethylfurfural [25] if the Co 2 (CO) 8 and Cr(CO) 6 carbonyl complexes weree mployed, respectively.T M-carbonyl complexes are also known to rapidly decompose into their corresponding TM-NPs in the presence of an ionic liquid such as 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIm]BF 4 ) under microwave irradiation. These resultsp rovide strong support for the hypothesis that, under the above-mentioned conditions, IA is regioselectively reduced through concerted hydrogenation of the conjugated externalC =Cd ouble bond and the carboxylic acidg roup.…”

“…We found earlier that TM-NPs derived from group 6c arbonyl complexes,i ncluding Fe 3 (CO) 12 ,C r(CO) 6 ,a nd W(CO) 6 ,a re highly effective catalysts for the selective transfer hydrogenation of LA to GVL in up to 93 %i solated yield. [22] Therefore, we first screenedt hese TM-NPs as potential catalysts for the conversion of IA to GiVL. Under syngas( 2H 2 /CO) pressure of 1250 psi (8618 kPa) and 225 8C, theseg roup 6T M-NPs were found to be active for this transformation, but the isolated GiVL yield was extremelyl ow (5-12 %, Ta ble S1 in the Supporting Information).…”

Iron‐Catalyzed Reductive Amination from Levulinic and Formic Acid Aqueous Solutions: An Approach for the Selective Production of Pyrrolidones in Biorefinery Facilities

“…[1][2][3][4][5][6][7][8] Some molecules derived from biomass, like levulinic acid (LA), has been extensively studied due to the possibility of its further transformation in highly aggregated value chemicals. [9][10][11][12][13][14][15][16][17][18][19] On this perspective, our Group recently developed a method to convert LA into gamma-valerolactone (GVL) using Fe(0) catalysts, water as solvent and formic acid (FA) as hydrogen source. [20] This methodology is environmental friendly since do not use expensive/non-abundant metal catalysts and employs a greener and recoverable organic solvent during the isolation step.…”