Clean and efficient conversion of renewable levulinic acid to levulinate esters catalyzed by an organic-salt of H4SiW12O40

Current Approaches to Alkyl Levulinates via Efficient Valorization of Biomass Derivatives

“…DRIFTS research on H 3 PW 12 O 40 /ZrO 2 further verified the existence of Brønsted and Lewis acid sites, which was in accordance with this hypothesis (Alsalme et al, 2010;Wu et al, 2016a). In addition, the modification of Keggin HPAorganosilica/ZrO 2 was proposed to prepare a hybrid catalyst, whereby a maximum AL yield of up to 95% was observed (Luan et al, 2018). Subsequently, several efforts have been devoted toward designing catalysts for the transformation of LA into ALs with enhanced stability, available active sites, and recyclability.…”

“…The LA esterification reaction has been investigated using several solid acid catalysts toward the production of ALs in comparatively high yields (Pileidis and Titirici, 2016). Heteropolyacid (HPA) is a special species of acid composed of a combination of certain metals (tungsten, molybdenum, or vanadium) and p-block non-metals (silicon, phosphorus, or arsenic) with acidic hydrogen and oxygen atoms, which are generally applied as reusable acid catalysts for the preparation of fine chemicals (Yan et al, 2013;Wu et al, 2016a,b,c;Zhou et al, 2016;Manikandan and Cheralathan, 2017;Ramli et al, 2017a;Zheng et al, 2017;Luan et al, 2018;Vilanculo et al, 2018;Lucas et al, 2019). Numerous structural combinations can be prepared upon adjusting the metal and non-metal used.…”

“…HPA implanted into the Wells-Dawson (WD) structure provided EL with a 76% yield upon heating at 78 • C for 10 h (Pasquale et al, 2012). Luan et al carried out the production of ethyl, methyl, and isobutyl levulinates using an organic-salt of H 4 SiW 12 O 40 as the catalyst (Luan et al, 2018). Manikandan and Cheralathan investigated heteropoly acid-supported silicalites in the synthesis of various ALs (Manikandan and Cheralathan, 2017).…”

Halloysite-Catalyzed Esterification of Bio-Mass Derived Acids

“…Therefore, a variety of solid acid catalysts derived from a plethora of chemically modified solid supports have been investigated as catalysts for this conversion. 9−17…”

Chemo‐ and Regioselective Synthesis of Arylated γ‐Valerolactones from Bio‐based Levulinic Acid with Aromatics Using H‐β Zeolite Catalyst

“…[8] LA, being one of the carbohydrates derived building block chemical identified by DOE, [9] is a promising biomass based chemical platform for industrial use through R&D. Recently, organic transformations of LA in presence of other biomass derived molecules to industrially valuable products (Scheme 1) are being pursued all over the world. Some prominent examples are: polymer precursors (ketals) through condensation of LA with glycerol, [10] diphenolic acid (a renewable plasticizeralternative to bisphenol A) from LA reacting with phenol, [11] alkyl levulinates (fuel oxygenates) via esterification of LA with C1-C4 linear and/or branched alcohols, [12] and production of liquid alkanes (fuels) from LA with formic acid via intermediate of γ-valerolactone (Gvl). It is worth mentioning here that formic acid is the by-product in LA synthesis from C6-sugars that can act as a hydrogen source for the synthesis of Gvl, a key step in a bio-refinery.…”