Finn Moeller

Electrochemical dehydration of carboxamides to nitriles is achieved using thiocyanate-mediated activation, avoiding stoichiometric reagents. In an undivided cell at ambient conditions, 18 aromatic and aliphatic substrates give good-to-excellent yields (up to 84%) with functional-group tolerance. Cyclic voltammetry supports an EC-type-mediated oxidation. The method is scalable with minimal loss in efficiency, offering a mild and sustainable route to nitriles.

An efficient electrochemical strategy for the dehydration of carboxamides to their corresponding nitriles is reported. This method replaces conventional dehydrating reagents with a thiocyanate-mediated electrochemical activation, providing a safer, milder, and more sustainable alternative. Under optimized conditions in an undivided cell, 18 examples of aromatic and aliphatic carboxamides were smoothly converted to the corresponding nitriles at ambient temperature in good-to-excellent yields (up to 84%). Hexafluoroisopropanol proved to be essential for reaction efficiency, while tetrabutylammonium thiocyanate acted as a redox mediator, as confirmed by cyclic voltammetry studies, which revealed an EC-type-mediated oxidation process. The method demonstrates broad functional-group tolerance, including halogenated, methoxylated, and sterically hindered substrates, as well as complex molecules derived from pharmaceuticals and natural products. Importantly, the protocol was successfully scaled up eightfold with minimal loss in yield, illustrating its robustness and practical applicability. Mechanistically, anodic oxidation of thiocyanate generates highly reactive species that activate the amide functionality, leading to nitrile formation via an oxidative dehydration pathway, while hydrogen evolution occurs at the cathode. This work expands the synthetic utility of electrochemical dehydration reactions and offers a valuable, environmentally responsible route to nitrile-containing compounds of broad relevance for pharmaceuticals, agrochemicals, and materials science.

Nature, Published online: 16 February 2026; doi:10.1038/s41586-026-10246-8

Active oxygen species (e.g., active hydroxyl (OH*) or lattice oxygen) generated at the anode enable a green pathway for C(OH)−C(OH) bond cleavage, but the mechanism requires further investigation. This work constructed two model catalysts with distinct capacities to yield active oxygen species, among which Ni(Al)-LDH, producing abundant lattice oxygen, exhibited higher activity and drove selective C(OH)−C(OH) bond cleavage to promote alcohols electrooxidation via a Mars-van-Krevelen mechanism.

Abstract

Selective cleavage of C(OH)−C(OH) bond is crucial for valorization of biomass, waste plastics and other organic compounds, while facing thermodynamic and kinetic barriers. Utilizing active oxygen species (e.g., active hydroxyl (OH*) or lattice oxygen) generated at the anode during water electrolysis provides a sustainable solution to achieve electrochemical activation of the C(OH)−C(OH) bond. However, elucidating the mechanisms of active oxygen species and their roles in enhancing product selectivity remains a challenge. Herein, we report a strategy to unravel the contribution of active oxygen species for C(OH)−C(OH) bond cleavage during alcohols electrooxidation, revealing that lattice oxygen promotes C(OH)−C(OH) bond cleavage and enhances product selectivity. We constructed NiAl-LDH and Ni(Al)-LDH as model catalysts, the latter derived through a “nano-tailoring” Al-leaching strategy. As a result, Ni(Al)-LDH facilitates lattice oxygen formation more readily, which acts as the primary active species for C(OH)−C(OH) bond cleavage and achieves ∼90% selectivity for formic acid production in ethylene glycol oxidation reaction (EGOR). The intrinsic mechanism involves that lattice oxygen participates in EGOR via the Mars-van-Krevelen mechanism and specifically induces C(OH)−C(OH) bond cleavage through an indirect pathway. This mechanistic insight into C(OH)−C(OH) bond cleavage mediated by lattice oxygen provides a valuable reference for designing selective catalysts in alcohols electrooxidation.

Urethane linkage requires harsh reaction conditions typically above 150°C temperature and 30–70 bar H₂ pressure for its degradation. An electrochemical strategy has been developed for C─N, C─P, and C─C bond formation using urethane as an efficient carbamoylation reagent at 60°C. This method was not only applied for up to 84% deconstruction of commercially available polyurethane and its articles but also for polymer backbone editing efficiently.

ABSTRACT

Plastics are essential, and their production is increasing. The rate of plastic recycling is extremely low, and end-of-life plastics are sent to landfills and oceans, which is alarming. Mechanical recycling is not a viable solution because it produces downgraded materials. Efficient methods for chemical recycling of plastics are essential. Polyurethane is a widely used plastic, and the presence of very stable carbamate functionality makes its recycling extremely difficult. Existing methods require expensive reagents and harsh reaction conditions, such as high temperature, high pressure, and precious metal catalysts such as iridium and ruthenium. Electrochemistry can potentially be used to develop sustainable methods that can operate under milder conditions using fewer reagents. We disclose that urethane serves as an efficient carbamoylation reagent under electrochemical conditions at lower temperatures to form C─N, C─P, and C─C bonds. This method works successfully to deconstruct commercially available polyurethane using different amines. Furthermore, the robustness of the method has been tested on daily life plastics made of polyurethane with additives, such as flexible tubing and mobile covers. This method has also been applied for polymer backbone editing by converting the urethane linkage to urea upon reaction with diamine.

Catalysis Rules! The year 2025 marks the 20^th anniversary of diarylprolinol silyl ethers in asymmetric organocatalysis. During the first decade after their discovery, these catalysts have been established as one of the most versatile tools in aminocatalysis. Although now considered mature, recent years have witnessed renewed innovation. We outlined these developments, demonstrating that this remains a rapidly evolving field.

ABSTRACT

A new chapter starts now. Since its discovery in 2005, the diarylprolinol silyl ether catalytic concept has emerged as a general and reliable aminocatalytic tool for the synthesis of enantioenriched molecules. Recently its combination with emerging technologies, as well as its application in more complex molecular systems has opened new avenues for novel enantioenriched scaffolds. In this review, we will highlight these recent developments, unfolding five primary categories that define new horizons in the use of diarylprolinol silyl ethers: Photochemical-, electrochemical-, dual-catalytic transformations, higher-order cycloadditions and applications in total synthesis of complex natural products.

This study investigates the impact of various p-block element impurities in the electrochemical reductive amination and reveals with Bi a less toxic alternative for Pb. The utilization of Bi as additive was further optimized by studying the impact of additive concentration, reaction temperature, and cathode material on amine yield, offering new possibilities to synthesize pharmaceuticals sustainably.

ABSTRACT

Amines are broadly utilized as solvents, pharmaceuticals, herbicides, or materials. A benign synthesis route to produce amines from carbonylic substrates is the electrochemical reductive amination, whereby electrons combined with a green proton source like water serve as formal reducing agent. Surprisingly, investigating various p-block elements as mediator for the electrochemical conversion of acetone in presence of methylamine revealed that only elements of the sixth period show an activity. Building up on these findings and the general low toxicity of Bi compared to Tl or Pb, the electrochemical hydrogenation of N-methylpropan-2-imine was optimized by studying the effect of Bi concentration, reaction temperature, and cathode material. Thus, this work highlights Bi as innovative mediator for the electrochemical reductive amination, whereby in presence of a few ppm-amounts of Bi at ambient temperatures high amine yields are achievable.

Lignins from γ-valerolactone organosolv fractionation were depolymerised in ethanol using unsupported molybdenum catalysts. Over 90% yields of low-molecular-weight lignin oil were obtained with minimal char formation, yields of the aromatic monomers being 7–16 wt%. Furthermore, we show how the product properties, like molecular weight and hydroxyl content, can be tuned by modifying the depolymerisation conditions.

Lignin is an attractive feedstock for a wide variety of applications ranging from aromatic chemicals and transportation fuels to resins and coatings. Emerging biorefinery concepts, like the organosolv process, enable the separation of all the lignocellulose components, and moreover, produce lignins of high quality and purity susceptible to valorisation by depolymerisation. In this work, we focus on the depolymerisation of lignins obtained by γ-valerolactone (GVL) organosolv fractionation of four biomass feedstocks, eucalyptus, white birch, sugarcane bagasse and Scots pine. We demonstrate that lignins extracted with the GVL process are depolymerised using unsupported molybdenum-based catalysts under reductive conditions in supercritical ethanol. As a result, over 90% yields of low-molecular-weight lignin oils are obtained with minimal char formation, yields of the aromatic monomers being 7–16 wt%. Furthermore, the design of experiments method is used to analyse the effect of depolymerisation conditions, catalyst, hydrogen loading and temperature, on the yields and properties of the product fractions. Notably, we show that the properties of the lignin oils and monoaromatics can be tuned towards the targeted application by modifying the depolymerisation conditions.

A mechanochemical Kolbe–Schmitt reaction of disodium catecholate enables the synthesis of mono- and dicarboxylated catechols at low temperature and CO₂ pressure. Directly derivatizing the resulting carboxylic acid and phenolic moieties in the obtained mixture provides plasticizer blends with efficiencies competitive to commercial benchmarks.

ABSTRACT

Catechol, an important aromatic platform molecule which can be derived from biomass, was carboxylated by mechanochemical Kolbe–Schmitt reaction of disodium catecholate with CO₂, providing a mixture of mono- and dicarboxylated catechol derivatives. While classical protocols require harsh reaction conditions, involving a high temperature and/or CO₂ pressure, a mild ball milling method was developed. This represents the first mechanochemical Kolbe–Schmitt reaction featuring a low CO₂ pressure and reactivity at room temperature. From the individual catechol-based mono- and dicarboxylic acid reaction products, a library of novel renewable plasticizers was synthesized through esterification of the carboxylic acid functionalities and O-acylation of the phenolic hydroxy groups. The resulting esters were evaluated in poly(vinylchloride) (PVC) and poly(lactic acid) (PLA), revealing plasticizing efficiencies competitive to benchmark commercial plasticizers. These efficiencies were maintained when the best performing ester substitution pattern was installed on the ball mill-derived mixture of mono- and dicarboxylated catechols, making resource intensive separation (e.g. chromatographic separation) of these ortho-dihydroxybenzene(di)carboxylic acids redundant.

An electrogenerated acid (EGA)-mediated enamine-imine cross-coupling enables the synthesis of polysubstituted pyridines. The protocol further achieves the first electrochemical C5-deuteration using D₂O as an economical deuterium source. Mechanistic and voltammetric studies reveal key reactive intermediates, and the method is readily scalable to synthetically valuable pyridine derivatives.

ABSTRACT

An electrochemical protocol for the regioselective synthesis of multi-substituted pyridines via a (3+3) annulation is described. The strategy utilizes enamine-iminium cross-coupling to construct the pyridine core with high functional group tolerance under mild reaction conditions. Alongside, C5-deuterated pyridines are achieved in a single step using deuterium oxide as the inexpensive deuterium source. In addition to the electro-redox events, electrogenerated acid (EGA) plays a decisive role in key bond-forming steps. Mechanistic studies, including control experiments and cyclic voltammetry, reveal the involvement of EGA and assist in identifying crucial reaction intermediates. The synthetic utility of the method is showcased by post-annulation derivatization, affording a diverse library of pyridine derivatives.

A Cu-Ni-W tri-component catalyst enables efficient nitrate-to-ammonia conversion under pulsed electrolysis. Combined experimental and theoretical studies attribute its performance to component synergism and regulated intermediates. Its facile adaptation for glycerol valorization to formic acid underscores a versatile system design concept, advancing electrochemical coupling strategies for a broad spectrum of industrially relevant reactions.

ABSTRACT

Electrochemical nitrate reduction represents a promising route for sustainable ammonia (NH₃) production, yet its practical deployment is constrained by the limited efficiency of state-of-the-art electrocatalysts and immature system architectures. Here, we report a generalist copper–nickel–tungsten tri-component tandem electrocatalyst via a sequential microwave-hydrothermal deposition route. Under pulsed electrolysis conditions, the catalyst delivers a remarkable Faradaic efficiency of 97.1% and a record-high ammonia yield rate of 43.87 mg h⁻¹ cm⁻². Online differential electrochemical mass spectrometry (DEMS) identifies key intermediates and associated pathways, while density functional theory (DFT) calculations elucidate the cooperative roles of each component: the copper component facilitates nitrate adsorption and deoxygenation, the nickel component promotes water dissociation for steady *H supply, and the tungsten component serves as a dynamic *H reservoir. This synergy efficiently suppresses hydrogen evolution and enhances ammonia selectivity. Furthermore, coupling with glycerol valorization (to formic acid) as the anodic reaction demonstrates the potential for energy-efficient ammonia electrosynthesis. Collectively, this work offers both design strategies and mechanistic understanding for next-generation multi-component tandem electrocatalysts targeting advanced nitrogen-based chemical synthesis.

Acid-generated carbocations are selectively trapped by sulfide and selenide donor molecules in the form of onium salts. Through manipulation of one of the donor's substituents, these onium salts undergo elimination towards the corresponding transchalcogenation products. This strategy enables the shuttling of toxic S and Se moieties, while providing a rational platform to improve reaction selectivity in carbocation functionalization.

ABSTRACT

Introducing functionalities via acid-mediated carbocation chemistry is conceptually straightforward, but typically lacks in selectivity and broad-scale applicability, which is further hampered by the need for toxic reaction partners. Here, we show that small S- and Se-based functionalities can be selectively and safely introduced into feedstock molecules via acid-catalyzed transchalcogenation reactions. A designable y-keto donor compound delivers the functionality through the formation of a trialkyl chalcogenonium intermediate that is prone to elimination in conjunction with the acid catalyst and its counteranion. We demonstrate how this strategy enables chemo-, regio-, and stereoselective construction of C(sp³)─S and ─Se bonds, offering clear advantages over classical acid-catalyzed carbocation functionalization.