Jonas Wuyts

The single-step syngas-to-dimethyl ether process offers both economic and technical advantages over the current two-step industrial synthesis. A highly active bifunctional Pd/CeO₂/γ-Al₂O₃ catalyst is reported by Yuemin Wang, Silke Behrens et al. in their Research Article (e202423273). Pd clusters/particles confined on the nanoparticulate ceria matrix feature abundant interfacial Pd²⁺ sites and adjacent O vacancies, accounting for the superior performance in both activity and stability.

Publication date: May 2025

Source: Chemical Engineering Research and Design, Volume 217

Author(s): Motshamonyane J. Phasha, Abdul M. Petersen, Johann F. Görgens

Nature, Published online: 24 March 2025; doi:10.1038/d41586-025-00869-8

Study dispels myth that order of names in a paper’s author list dictates perception of success.

The reversible derivation of the –CHO group of furfural with N,N-Dimethylhydrazine not only restores the nucleophilicity of the furan ring toward formaldehyde but also opens an alternative mechanism to the classical acid-catalyzed pathway for the selective hydroxymethylation of the furanic ring of furfural.

In this report, the synthesis of 5-hydroxymethylfurfural from concentrated feeds of two low-cost and industrially abundant chemicals: Furfural and formaldehyde is explored. By adjusting the acidity of the solvent, an alternative mechanism is discovered in which the reaction selectivity stops to the hydroxymethylation step, in contrast to previously reported acid-catalyzed pathways leading to the formation of the bisfuranic dimer as a major product. One of the keys of this study relies on the reversible derivation of the –CHO group of furfural with N,N-Dimethylhydrazine which plays a dual role: (1) it restores the nucleophilicity of the furan ring and (2) it reacts with HCHO to form in situ an electrophilic zwiterrionic species stabilized through hydrogen transfer. By means of experimental and theoretical investigations, this reaction is optimized and it is discovered that guaiacol can be used as a bio-based and safe solvent. Under optimized conditions, the hydroxymethylation of the furan ring of furfural occurs with more than 95% selectivity, at only 50 °C and with a stoichiometric amount of HCHO. A concentrated feed of furfural as high as 40 wt% in guaiacol can be employed without impacting the reaction selectivity, leading to an improvement of the reactor productivity to about 25 kg m⁻³ h⁻¹. The recovery of the reaction products and the recycling of the N,N-dimehylhydrazone are also discussed.

Metathesis and reversible catalytic reactions are fundamentally intriguing and powerful tools in modern synthetic chemistry. While most reversible catalytic reactions are predicated on breaking and forming reactive functional groups, the ability to leverage the C–H bond as a functional group into metathesis reactions has proved to be exceptionally challenging. Here, we develop a C–H/C–X metathesis reaction through a radical swapping protocol where a hydrogen and halogen are traded between molecules via reversible hydrogen atom transfer (HAT) and halogen atom transfer (XAT) that allows for mild C–H halogenation. The reversibility of this process allows for selective dehalogenation of polyhalogenated products to form monohalogenated products. Leveraging the reversibility of this process, halogenated organic pollutants can also serve as a halogen source for C–H halogenation. In the broader context, this work establishes that incorporating reversible metathesis logic in C–H bond functionalization can provide complementary advantages in synthetic strategies.

Nature, Published online: 12 March 2025; doi:10.1038/d41586-025-00287-w

William Mills aims to make the website for his laboratory more than just a channel for promoting publications and research projects to the outside world.

Aldolases and ThDP-dependent enzymes have played important roles in the C─C bond formation of formaldehyde, a versatile C1 molecule. In this review, we summarize the recent progresses in the enzymatic C─C bond formation reactions of formaldehyde and multi-enzyme cascade reactions, that have enabled the synthesis of complex multifunctional compounds from formaldehyde via hydroxymethylation.

Abstract

Given the importance of multifunctional compounds and the versatile reactivity of one-carbon (C1) molecule formaldehyde, the synthesis of value-added multifunctional compounds from formaldehyde and other simple molecules via C─C bond formation has been the focus of intensive investigations. In view of the uncontrollable reactivity of formaldehyde, the employment of formaldehyde in the C─C bond formation is considered as one of the most challenging tasks in organic synthesis. Aldolases and thiamine pyrophosphate (ThDP)-dependent enzymes have been regarded as the most potential biocatalytic tools for carbon–carbon (C─C) bond formation. In the present review, aldolases and ThDP-dependent enzymes are shown to be the simplest and powerful biocatalytic platforms for controlling the reactivity of formaldehyde to effectively produce multifunctional compounds. The recent advances in the construction of multienzymatic cascade reactions for the synthesis of complex multifunctional compounds from formaldehyde via C─C bond formation have also been presented.

The review begins by discussing lignin and its structural complexity, followed by challenges in elucidating depolymerization products and the analytical techniques used. It then focuses on the chemical structure of synthetic lignin oligomers, their synthesis mechanisms, and their significance in current science. Finally, scientific gaps are identified, and future research directions are proposed to guide scientists reading this work.

Abstract

Lignin is the second most abundant renewable material after cellulose. However, its economic use is currently relegated to low-value energy production. This biomaterial holds great potential as a source of renewable biofuels, bio-based chemicals, advanced materials, and integrated biorefineries. Fractionation and depolymerization methods yield liquid repositories of promising aromatic monomers and lignin oligomers (LO) that retain many of the structural components found in the native material. However, analyzing this complex mixture is challenging due to the wide range of molecular sizes and heterogeneous chemical structure, which makes their structural elucidation a critical obstacle – unlocking the full potential of lignin hinges upon developing appropriate standards and analytical methods to address existing knowledge gaps. This review provides a comprehensive examination of current analytical techniques for elucidating the chemical structure of lignin oligomers, exploring synthesis methods, molecular structures, and their advantages and limitations. Built upon these findings, opportunities for synergy between synthetic oligomers and lignin utilization can be revealed, such as bioactive compound production and biorefinery integration. Moreover, we underscore the need for standardized analytical methods to facilitate the design of lignin oligomer standards and their diverse applications.

A novel, sustainable, and scalable method for the efficient depolymerization of polyurethane foam waste is presented, employing ionic liquids and superbase catalysis as reaction media at 95–98 °C, and highlighting the potential for industrial application of the resulting polyol.

Abstract

This study introduces a novel and sustainable approach using Ionic Liquids (ILs) as a non-innocent solvent that enhances the performance of the basic catalysts to depolymerize polyurethane foam wastes (PUFWs) through hydrolysis, alcoholysis or aminolysis under mild conditions. The system is stable, fully recoverable, and reusable. Hydrolysis of PUFWs can occur in just 2 minutes at 95–98 °C, producing a white polyol that is easily separated and reused in new polyurethane synthesis. The method was successfully scaled up to depolymerize 200 g of PUFW per batch (1 kg overall depolymerization system). This scalability, combined with the medium‘s reusability without loss of effectiveness, highlights its strong potential for industrial applications.

A novel and efficient catalytic transfer hydrogenation (CTH) protocol is developed for converting dimethyl 1, 4-cyclohexane dicarboxylate (DMCD) to 1, 4-cyclohexanedimethanol (CHDM). Methanol served as both the hydrogen donor and solvent, while a cost-effective Cu/ZnO/Al₂O₃/ZrO₂ catalyst is employed. At 235 °C, the process achieves 96.61 % conversion with 60.71 % selectivity.

Abstract

A novel and efficient protocol for the conversion of dimethyl 1, 4-cyclohexane dicarboxylate (DMCD) into 1, 4-cyclohexanedimethanol (CHDM) was proposed via catalytic transfer hydrogenation (CTH). In this approach, methanol functioned as both the hydrogen donor and the solvent, and a cost-effective Cu/ZnO/Al₂O₃/ZrO₂ catalyst was utilized for facilitating the reaction. Under the specified conditions at 235 °C, a conversion of 96.61 % with a selectivity of 60.71 % was achieved. To elucidate the reaction mechanism, comprehensive characterizations were conducted to examine the catalysts with varying ZrO₂ contents. The investigation revealed that the reaction begins with the adsorption of DMCD and methanol onto the acidic sites of the catalyst, followed by their activation on the reduced-state Cu.

The Cover Feature shows how we have harnessed benign chemical processes to synthesize carbamate insecticides from agricultural waste materials, thereby meeting several green chemistry criteria. The novel molecules demonstrate targeted effectiveness against pests while maintaining positive ecological profiles. Their renewable source and selective potency are encouraging in our push towards sustainable agricultural practices. More information can be found in the Research Article by S. Sadula, D. G. Vlachos and co-workers.

Abstract

The ever-increasing prevalence of diseases and inadequate resources on Earth are threats to society. Biomass is an abundant resource, and bioactive compounds produced from biomass are environmentally benign in contrast to conventional chemical synthesis methods, which frequently depend on non-renewable resources. In addition, the functionalized monomers from biomass allow the atom economical synthesis of bioactive molecules. This review aims to provide insight into the synthesis of bioactive molecules from the lignocellulose-derived platform chemicals. Existing methodology and catalytic systems are summarized for the synthesis of targeted bioactive molecules from cellulose, hemicellulose, and lignin-derived platform chemicals. The biological activities of bioactive molecules obtained from biomass, such as antioxidant, anti-inflammatory, and anticancer properties, are discussed.

Organocatalyzed group transfer polymerization (O-GTP) of muconic esters leads to bio-sourced and degradable polymers analogous to polyacrylates. This O-GTP method proves ultra-fast, converting 100 % of the monomer in one minute in toluene at room temperature. Chemical modification of the internal double bonds offers additional leverage either for modulating polymer properties or for chemical degradation.

Abstract

The quest for polymers that would be at the same time bio-based and degradable after usage, in addition to offering chemical post-modification options, remains a daunting challenge in contemporary polymer science. Despite advances in polymer chemistry, attempts at controlling the chain-growth polymerization of muconate esters remain unexplored. Here we show that dialkyl muconates can be rapidly polymerized by organocatalyzed group transfer polymerization (O-GTP). O-GTP is conducted to completion at room temperature in toluene within a few minutes, using 1-ethoxy-1-(trimethylsiloxy)-1,3-butadiene (ETSB) as initiator and 1-tert-butyl-4,4,4-tris(dimethylamino)-2,2-bis[tris(dimethylamino)-phosphoranylidenamino]-2 λ ${\lambda }$ 5,4 λ ${\lambda }$ 5 catenadi(phosphazene) (P₄-t-Bu) as catalyst. Chain extension experiments and synthesis of all muconate-type block copolymers can also be achieved. Furthermore, polymuconates are amenable to facile post-polymerization modification reactions. This is showcased through the hydrolysis of the ester side chains leading to well-defined poly(muconic acid), and by epoxidation of the C=C double bonds of the main chain. Last but not least, these internal alkene groups can be selectively cleaved by ozonolysis, demonstrating the upcyclability of polymuconates under oxidative conditions. This work demonstrates that polymuconates constitute a unique platform of bio-based polymers, easily modifiable in addition to being chemically degradable under user friendly experimental conditions.

Nature Reviews Chemistry, Published online: 04 October 2024; doi:10.1038/s41570-024-00652-9

To date, monomer yields from lignin are limited to those attainable through C–O bond cleavage. Cleaving C–C bonds often leads to deleterious product degradation and low monomer yields. Herein we review lignin C–C cleavage reports and advocate for a standardized reporting of yields.

Important developments, over the last five decades, towards realization of sustainable chemicals manufacture, are discussed. They include the use of waste biomass and CO₂ as a raw material, renewable electricity as the energy source and chemo- and biocatalysis, with whole cells or cell-free enzymes, including the use of electro(bio)catalysis and photo(bio)catalysis, as the facilitators.

Abstract

The development of sustainable chemistry underlying the quest to minimize and/or valorize waste in the carbon-neutral manufacture of chemicals is followed over the last four to five decades. Both chemo- and biocatalysis have played an indispensable role in this odyssey. in particular developments in protein engineering, metagenomics and bioinformatics over the preceding three decades have played a crucial supporting role in facilitating the widespread application of both whole cell and cell-free biocatalysis. The pressing need, driven by climate change mitigation, for a drastic reduction in greenhouse gas (GHG) emissions, has precipitated an energy transition based on decarbonization of energy and defossilization of organic chemicals production. The latter involves waste biomass and/or waste CO₂ as the feedstock and green electricity generated using solar, wind, hydroelectric or nuclear energy. The use of waste polysaccharides as feedstocks will underpin a renaissance in carbohydrate chemistry with pentoses and hexoses as base chemicals and bio-based solvents and polymers as environmentally friendly downstream products. The widespread availability of inexpensive electricity and solar energy has led to increasing attention for electro(bio)catalysis and photo(bio)catalysis which in turn is leading to myriad innovations in these fields.