Biomass-derived Building Block Research Articles

Front Cover: Organocatalytic Upgrading of Biomass Derived Building Blocks (Eur. J. Org. Chem. 22/2023)

Front Cover: Organocatalytic Upgrading of Biomass Derived Building Blocks (Eur. J. Org. Chem. 22/2023)

Organocatalytic Upgrading of Biomass Derived Building Blocks

AbstractThe depletion of finite primary fossil fuels we are facing makes necessary a deep metamorphosis in fundamental parts of the chemical industry. A progressive transition from petro‐based starting materials toward renewable biomass‐derived sources will have to take place in the synthesis of added‐value chemicals, important for our everyday life, such as pharmaceuticals, polymers, agrochemicals etc. Moreover, greener processes, carried out under friendlier reaction conditions, must be designed to address current concerns about the climate change and the resulting pressing need to reduce the environmental footprint of chemical processes. To this end, organocatalysis could offer a valuable opportunity for upgrading biomass‐derived platform molecules in line with the principles of Green Chemistry. This review presents some of recent and remarkable advancements in this emerging area. Organocatalysis has proven to be an efficient tool to transform low value bio‐based renewable platform building blocks into new high value bio‐based chemicals, with potential applications as synthetic intermediates, innovative materials and pharmaceutically active compounds.

Natural lignocellulose welded Zr–Al bimetallic hybrids for the sustainable conversion of xylose to alkyl levulinate

The processing of C6 sugars to alkyl levulinate (AL), a versatile biomass-derived building block, can be readily implemented via the straightforward acid-catalyzed reaction in alcohol medium while it remains a challenge to produce AL from C5 sugars in the one-pot procedure over a monolithic catalyst. In this contribution, a budget and multifunctional natural lignocellulose welded Zr–Al bimetallic hybrid (ZrAl@CS-MSA) has been successfully constructed with crude corn stalk as a sustainable support. The becoming Lewis and Brønsted acid sites of ZrAl@CS-MSA catalyst guarantee a high AL yield of 54.3% from xylose via a one-pot process in a renewable n-butanol medium. Experimental findings revealed that the sulfonic group of ZrAl@CS-MSA plays a significant role in the xylose dehydration, furfuryl alcohol etherification and alcoholysis reactions while Zr species is in charge of the transfer hydrogenation of furfural. The Al species enclosed in ZrAl@CS-MSA can regulate its Brønsted and Lewis acidity, accelerating the etherification and alcoholysis reactions as well as alleviating the over hydrogenation of AL. This work opens a green, sustainable and reliable avenue for producing C5 sugar-based AL using natural lignocellulose-related multifunctional catalysts.

Solvent-Resistant Thin-Film Composite Membranes from Biomass-Derived Building Blocks: Chitosan and 2,5-Furandicarboxaldehyde

To address the increasing interest in environmental issues, green and sustainable material-based membranes have attracted significant research interest with the promise to replace fossil-based membranes and to reduce waste generation. In this work, more sustainable thin-film composite (TFC) membranes are designed and fabricated via interfacial polymerization of green building blocks, namely, shrimp farming waste chitosan in the aqueous phase and plant-based 2,5-furandicarboxaldehyde in the organic phase, on an upcycled polyethylene terephthalate porous support. The TFC membranes showed excellent acetone permeance up to 12 L m–2 h–1 bar–1 with a molecular weight cutoff value of approximately 317 g mol–1. The membrane separation performance was optimized by fine-tuning the building block concentrations, which provided a new upper-bound in the plot of acetone permeance versus styrene dimer rejection. In addition, for the first time, TamiSolve was employed as a green solvent to activate the selective layer of the chitosan-based TFC membrane, resulting in a significant enhancement in the permeance of diverse pure solvents including ethanol, methyl ethyl ketone, acetone, and acetonitrile with no remarkable defects and high solute rejections. Our proposed green TFC fabrication platform enables the replacement of toxic and fossil-based solvents and reagents in developing high-performance and solvent-resistant nanofiltration membranes.

Recent Advances in Catalytic Conversion of Biomass to 2,5-Furandicarboxylic Acid

Converting biomass into high value-added compounds has attracted great attention for solving fossil fuel consumption and global warming. 5-Hydroxymethylfurfural (HMF) has been considered as a versatile biomass-derived building block that can be used to synthesize a variety of sustainable fuels and chemicals. Among these derivatives, 2,5-furandicarboxylic acid (FDCA) is a desirable alternative to petroleum-derived terephthalic acid for the synthesis of biodegradable polyesters. Herein, to fully understand the current development of the catalytic conversion of biomass to FDCA, a comprehensive review of the catalytic conversion of cellulose biomass to HMF and the oxidation of HMF to FDCA is presented. Moreover, future research directions and general trends of using biomass for FDCA production are also proposed.

Production of Acrylic Acid from Biomass-Derived Fumaric Acid under Hydrothermal Conditions

Production of energy and chemicals from biomass resources has been regarded as one promising method to address the challenge of global warming. In this research, production of acrylic acid from fumaric acid, one of the biomass-derived building blocks, is proposed. CuO was employed as a solid oxidant, which showed excellent activity and selectivity for the production of acrylic acid, and water played an essential role in acting as not only a solvent but also a catalyst in this process. An optimum acrylic acid yield of 76.4% was successfully obtained after the reaction of fumaric acid with CuO at 300 °C for only 60 s.This research provides a green and highly efficient way to produce value-added chemicals from biomass-derived building blocks, and thus is promising for practical application.

Value-Added Bio-Chemicals Commodities from Catalytic Conversion of Biomass Derived Furan-Compounds

The depletion of fossil resources in the near future and the need to decrease greenhouse gas emissions lead to the investigation of using alternative renewable resources as raw materials. One of the most promising options is the conversion of lignocellulosic biomass (like forestry residues) into bioenergy, biofuels and biochemicals. Among these products, the production of intermediate biochemicals has become an important goal since the petrochemical industry needs to find sustainable alternatives. In this way, the chemical industry competitiveness could be improved as bioproducts have a great potential market. Thus, the main objective of this review is to describe the production processes under study (reaction conditions, type of catalysts, solvents, etc.) of some promising intermediate biochemicals, such as; alcohols (1,2,6-hexanetriol, 1,6-hexanetriol and pentanediols (1,2 and 1,5-pentanediol)), maleic anhydride and 5-alkoxymethylfuran. These compounds can be produced using 5-hydroxymethylfurfural and/or furfural, which they both are considered one of the main biomass derived building blocks.

Esterification of Levulinic Acid to Levulinate Esters in the Presence of Sulfated Silica Catalyst

Levulinic acid (LA) is one of biomass derived building block chemicals with various applications. Catalytic esterification of LA with alkyl alcohol produces levulinate ester which can be applied as fragrance, flavouring agents, as well as fuel additives. In this study, a series of sulfated silica (SiO2) catalyst was prepared by modification of SiO2 with sulfuric acid (H2SO4) at different concentrations; 0.5 M to 5 M H2SO4. The catalysts were characterized, and tested for esterification of LA with ethanol to ethyl levulinate (EL). The effect of various reaction parameters including reaction time, catalyst loading and molar ratio of LA to ethanol on esterification of LA to EL were inspected. The catalyst with high concentration of acid sites seemed suitable for LA esterification to EL. Among the sulfated SiO2 catalysts tested (0.5 M-SiO2, 1 M-SiO2, 3 M-SiO2 and 5 M-SiO2), 3 M-SiO2 exhibited the highest performance with the optimum EL yield of 54% for reaction conducted at reflux temperature for 4 h, 30% 3 M-SiO2 loading and LA to ethanol molar ratio of 1:20. Besides, the reusability of 3 M-SiO2 catalyst for LA esterification with ethanol was examined for five cycles. Esterification of LA with methanol and 1-butanol were also carried out for methyl levulinate (ML) and butyl levulinate (BL) productions with 69% and 40% of ML and BL yields, respectively. This study demonstrates the potential of sulfated SiO2 catalyst for levulinate ester production from LA at mild process condition.

Expanding the biomass derived chemical space.

Biorefinery aims at the conversion of biomass and renewable feedstocks into fuels and platform chemicals, in analogy to conventional oil refinery. In the past years, the scientific community has defined a number of primary building blocks that can be obtained by direct biomass decomposition. However, the large potential of this "renewable chemical space" to contribute to the generation of value added bio-active compounds and materials still remains unexplored. In general, biomass derived building blocks feature a diverse range of chemical functionalities. In order to be integrated into value-added compounds, they require additional functionalization and/or covalent modification thereby generating secondary building blocks. The latter can be thus regarded as functional components of bio-active molecules or materials and represent an expansion of the renewable chemical space. This perspective highlights the most recent developments and opportunities for the synthesis of secondary biomass derived building blocks and their application to the preparation of value added products.

ESTERIFICATION OF RENEWABLE LEVULINIC ACID TO LEVULINATE ESTERS USING AMBERLYST-15 AS A SOLID ACID CATALYST

Levulinic acid (LA) is a versatile biomass-derived building block as it can be used for the synthesis of organic chemicals as alternative to the depleting fossil fuel resources. Levulinate esters, obtained from catalytic esterification of LA with alcohol, can be used in many applications such as fragrance and fuel additives. In this study, ion-exchange resins Amberlyst-15 was employed as solid acid catalyst for esterification of LA with methanol for methyl levulinate (ML) production. The effect of reaction time, catalyst loading, and molar ratio of LA to methanol, was investigated on LA esterification to ML at the reflux condition. The optimum ML yield of 82% was obtained from reaction conducted at reflux temperature for 5h, using 30% of Amberlyst-15 loading, and 1:20 of LA to methanol molar ratio. The reusability of Amberlyst-15 for ML production was examined for five successive reactions. In addition, Amberlyst-15 catalyst, employed in the esterification of LA with ethanol and 1-butanol for ethyl levulinate (EL) and butyl levulinate (BL), respectively, registered good performance. Yields of 71% and 55% have been obtained for EL and BL, respectively. Amberlyst-15 is a promising solid acid catalyst for production of biomass derived levulinate esters at mild process conditions.

Biomass Derived Chemicals: Furfural Oxidative Esterification to Methyl-2-furoate over Gold Catalysts

The use of heterogeneous catalysis to upgrade biomass wastes coming from lignocellulose into higher value-added chemicals is one of the most explored subjects in the prospective vision of bio-refinery. In this frame, a lot of interest has been driven towards biomass-derived building block molecules, such as furfural. Gold supported catalysts have been successfully proven to be highly active and selective in the furfural oxidative esterification to methyl-2-furoate under mild conditions by employing oxygen as benign oxidant. Particular attention has been given to the studies in which the reaction occurs even without base as co-catalyst, which would lead to a more green and economically advantageous process. The Au catalysts are also stable and quite easily recovered and represent a feasible and promising route to efficiently convert furfural to methyl-2-furoate to be scaled up at industrial level.

Heterocycle construction using the biomass-derived building block itaconic acid

This critical review discusses the diverse array of heterocyclic motifs that are available from the biomass-derived building block itaconic acid.

Lipase‐Catalyzed (Trans)esterification of 5‐Hydroxy‐ methylfurfural and Separation from HMF Esters using Deep‐Eutectic Solvents

5-Hydroxymethylfurfural (HMF) is a valuable biomass-derived building block. Among possible HMF valorization products, a broad range of HMF esters can be synthesized. These HMF esters have found some promising applications, such as monomers, fuels, additives, surfactants, and fungicides, and thus several catalytic approaches for HMF (trans)esterifications have been reported. The intrinsic reactivity of HMF is challenging, forcing the use of mild reaction conditions to avoid by-product formation. This paper explores the lipase-catalyzed (trans)esterification of HMF with different acyl donors (carboxylic acids and methyl- and ethyl esters) mostly in solvent-free conditions. The results demonstrate that lipases may be promising alternatives for the synthesis of HMF esters-with high productivities and reactions at high substrate loadings-provided that robust systems for lipase immobilization are applied to assure an adequate reusability of the enzymes. Once (trans)esterifications have been conducted, the separation of unreacted HMF and HMF esters is performed by using deep-eutectic solvents (DES) as separation agents. DES are able to dissolve hydrogen-bond donors (e.g., HMF), whereas non-hydrogen-bond donors (in this case HMF esters) form a second phase. By using this approach, high ester purities (>99 %) and efficiencies (up to >90 % HMF ester recovery) in separations were obtained by using choline chloride-based DES.

Catalytic selective etherification of hydroxyl groups in 5-hydroxymethylfurfural over H4SiW12O40/MCM-41 nanospheres for liquid fuel production

5-Hydroxymethylfurfural (HMF) is an important biomass-derived building block, but production and sustainable utilization of HMF remain challenging due to reactions of the highly reactive functional groups of this compound. H4SiW12O40/MCM-41 nanospheres were developed that exhibit 84.1% selectivity to 5-ethoxymethylfurfural (EMF) when HMF conversion reaches 92.0%, during etherification of 5-hydroxymethylfurfural (HMF) with ethanol under mild conditions. The catalyst could be reused, and its activity remained unaffected over five cycles. The strong acidity of the catalyst significantly enhanced etherification. The acetalized byproducts, 5-(diethoxymethyl)-2-furanmethanol and the HMF-dimer (5,5′(oxy-bis(methylene))bis-2-furfural), can be converted into HMF and then transformed to the main product, EMF, by using this catalyst to shift the reaction equilibrium.

Isosorbide Polyesters from Enzymatic Catalysis

The synthesis of isosorbide aliphatic polyesters is demonstrated by the use of Novozym 435, a catalyst consisting of Candida antarctica lipase B immobilized on a macroporous support. Several experimental procedures were tested and azeotropic distillation was most effective in removing low mass byproduct. Furthermore, the use of diethyl ester derivatives of diacid comonomers gave isosorbide copolyesters with highest isolated yield and molecular weights. The length of the diacid aliphatic chain was less restrictive, but with a clear preference for longer aliphatic chains. The molecular mass values of the obtained products were equivalent or higher than those obtained by nonenzymatic polymerizations, a clear illustration of the potential of enzymatic over conventional catalysis. The ability of Novozym 435 to catalyze the synthesis of isosorbide polyester with weight-average molecular weights in excess of 40 000 Da was unexpected given that isosorbide has two chemically distinct secondary hydroxyl groups. This is the first example in which isosorbide polyesters were synthesized by enzyme catalysis, opening a large array of possibilities for this important class of biomass-derived building blocks. Because these polymers are potential biomaterials, the total absence of conventional Lewis acid catalyst residues represents a major improvement in the toxicity of the material.

Ionic Liquid-Mediated Formation of 5-Hydroxymethylfurfural—A Promising Biomass-Derived Building Block

Ionic Liquid-Mediated Formation of 5-Hydroxymethylfurfural—A Promising Biomass-Derived Building Block