Catalytic Coupling Research Articles

On-Demand Catalytic Platform for Glycerol Upgrade and Utilization.

Surplus byproducts generated during biomass exploitation, such as glycerol from biodiesel manufacturing, seriously undermine the credibility of renewable energy policies. Here, we establish an on-demand catalytic platform for the upgrade and utilization of glycerol via photoelectro-bioelectro-heterogeneous coupling catalysis. Combining theoretical descriptors, specifically the highest occupied molecular orbital energy levels and dual local softness values, along with systematic experimental validation, we demonstrated the reaction activity of glycerol and its upgraded products on BiVO4 photoelectrodes. Glyceric acid was identified as the optimal biofuel candidate through monohydroxyl oxidation of glycerol. Coupling the preferential upgrading of glycerol to glyceric acid by night and its reuse as biofuel by day, a hybrid biophotoelectrochemical system delivered an open-circuit voltage of 0.89 ± 0.02 V and a maximum power density of 0.41 ± 0.03 mW cm-2 with stable diurnal operation for over 10 days. This successful model construction provides valuable insights into the strategic integration of multiple energy sources and the exploration of coupling-catalytic platforms, charting new territory for the next-generation sustainable energy systems.

Stereoselective Synthesis of (Z)-Acrylic Nitriles from the Ruthenium-Catalyzed Coupling Reaction of Nitriles with Unsaturated Carbonyl Compounds via C-C Bond Cleavage.

Acrylic nitriles are a versatile class of synthetic precursors for a variety of pharmaceutically active compounds, as well as for nitrile polymers. We devised a stereoselective synthesis of (Z)-acrylic nitriles from the Ru-catalyzed coupling reaction of nitriles with unsaturated carbonyl compounds via C-C bond cleavage. Both carbon KIE and Hammett correlation data indicated that C-C bond cleavage is the rate-determining step for the coupling reaction. Several bioactive (Z)-acrylic nitriles were synthesized by using the catalytic coupling method.

Photothermal Catalysts, Light and Heat Management: From Materials Design to Performance Evaluation

AbstractPhotothermal catalysis, a frontier in heterogeneous catalysis, combines light‐driven and thermally enhanced chemical reactions to optimize energy use and reaction efficiencies at catalytic active sites. By leveraging photothermal conversion, this approach links renewable energy sources with industrial chemical processes, offering significant potential for sustainable applications. This review categorizes photothermal catalysis into three types: light‐driven thermocatalysis, thermally enhanced photocatalysis, and photo‐thermo coupling catalysis. Each category is analyzed, emphasizing mechanisms, performance factors, and the role of advanced materials such as plasmonic nanoparticles, semiconductors, and hybrid composites in enhancing light absorption, thermal distribution, and catalytic stability. Key challenges include achieving uniform thermal and photonic energy distributions within catalytic reactors and developing accurate performance evaluation metrics. Applications such as CO₂ reduction, ammonia synthesis, and plastic upcycling highlight the environmental and industrial relevance of this technology. The review identifies limitations and suggests innovations in materials design and energy‐storing mechanisms to enable continuous catalytic processes. Future directions emphasize photothermal catalysis's potential to transform sustainable energy systems and advance green chemical production. This synthesis aims to guide research and foster practical adoption of photothermal technologies at an industrial scale.

Ppm level Pd catalytic Suzuki-Miyaura coupling reaction in water and its application in the synthesis of Bixafen

ppm level Pd catalytic Suzuki-Miyaura coupling reaction in water and its application in the synthesis of Bixafen

Catalytic Asymmetric Oxidative Coupling between C(sp3)-H Bonds and Carboxylic Acids.

The direct enantioselective functionalization of C(sp3)-H bonds in organic molecules could fundamentally transform the synthesis of chiral molecules. In particular, the enantioselective oxidation of these bonds would dramatically change the production methods of chiral alcohols and esters, which are prevalent in natural products, pharmaceuticals, and fine chemicals. Remarkable advances have been made in the enantioselective construction of carbon-carbon and carbon-nitrogen bonds through the C(sp3)-H bond functionalization. However, the direct enantioselective formation of carbon-oxygen bonds from C(sp3)-H bonds remains a considerable challenge. We herein report a highly enantioselective C(sp3)-H bond oxidative coupling with carboxylic acids. The method applies to allylic and propargylic C-H bonds and employs various carboxylic acids as oxygenating agents. The method successfully synthesized a range of chiral esters directly from readily available alkenes and alkynes, greatly simplifying the synthesis of chiral esters and related alcohols.

Selective Ni(I)/Ni(III) Process for Consecutive Geminal C(sp3)-C(sp2) Bond Formation.

Ni-catalyzed multicomponent cross-couplings have emerged as a powerful strategy for efficiently constructing complex molecular architectures from a diverse array of organic halides. Despite its potential, selectively forming multiple chemical bonds in a single operation, particularly in the realm of cross-electrophile coupling catalysis, remains a significant challenge. In this study, we have developed a consecutive open-shell reductive Ni catalysis, enabling the formation of two geminal C(sp3)-C(sp2) bonds from two stereoelectronically similar C(sp2)-I reactants in conjunction with a methylene electrophile. Using zirconaaziridine and elemental Mg0 as reductants, this protocol exhibits broad applicability across a wide range of (hetero)aromatic, alkenyl, and glycal halides, allowing for the rapid assembly of medicinally relevant scaffolds with excellent functional group tolerance. Further kinetic studies suggest a dual "sequential reduction" catalytic process facilitated by a zirconaaziridine-mediated redox-transmetalation process in Ni catalysis. Notably, the concerted oxidative addition of Ni(I)-I across a C(sp2)-I bond, as well as the halide atom abstraction among various C(sp3) electrophiles by an open-shell C(sp2)-Ni(I) species, can proceed with high selectivity. The use of an unsymmetrical methylene electrophile with exceptionally high reactivity in XEC resulted in the rapid accumulation of a benzylic or allylic electrophile intermediate at the outset of reaction, thereby finely controlling the coupling sequence.

Synthesis of Functionalized Benzo[f]chromanes and Hydroxyalkyl Naphthols: Catalytic Coupling of Naphthols and Allylic Alcohols

AbstractCatalytic dearomatization of arenols is an uphill task that can serve as a powerful method to construct C−C bonds with unsaturated coupling partners. Herein, a simple and efficient strategy for coupling naphthols with allylic alcohols is reported. A single Ru(II) pincer catalyzed coupling of naphthols with primary allylic alcohols led to the formation of benzo(f)chromanes, whereas the use of secondary alcohols delivered the hydroxyalkyl naphthols. Broad substrate scope and good functional group tolerance are demonstrated. Notably, a high diastereoselectivity is attained on chromanes. Hydroxyalkyl naphthols are synthetically transformed into spiroethers, and dearomative bromination is achieved on chromanes. Mechanistic studies revealed the involvement of tandem reactions, a formal O−H bond activation of allylic alcohols by an active catalyst via amine‐amide metal‐ligand cooperation provided α‐β, unsaturated carbonyl intermediates, which further underwent 1,4 conjugate addition with dearomatized naphthols. One of the crucial intermediates, naphthyl radical, is elucidated by EPR studies and trapped using a radical scavenger. Liberated hydrogen and water molecules are the only byproducts in these transformations.

Synergistic Pd/Cu-Catalyzed Asymmetric Csp3–Csp3 Coupling of 1,3-Dienes with 2-Acylimidazoles

AbstractThe catalytic asymmetric coupling of 1,3-dienes with carbon nucleophiles is an important process for forming Csp3–Csp3 bonds. Here, we describe a synergistic Pd/Cu-catalyzed coupling of 1,3-dienes with 2-acylimidazoles. This reaction produces 2-acylimidazole derivatives that have α,β-adjacent stereocenters in moderate yields with good to excellent stereoselectivity.

Machine learning-guided engineering of phosphocholine cytidylyltransferase for improved activity and halotolerance in citicoline production

Phosphocholine cytidylyltransferase (CCT) is an important biocatalyst for citicoline (CDP-choline) production. However, it suffers from relatively low catalytic activity and halotolerance when it was applied in the one-pot catalytic system coupling with the acetylphosphate based ATP regeneration system. A machine learning guided directed evolution approach was applied to simultaneously improve activity and halotolerance of Saccharomyces cerevisiae CCT (ScCCT), through random mutation on “hot-spot” regions predicted by selected models trained on different combinatory datasets generated by site-directed mutagenesis and random mutagenesis. The most desirable variant M3 (P347S/P365L/K340T) exhibited an approximately 1.4 folds improvement in final titer of CDP-choline (182 mM) comparing with WT. This research proves that machine learning can improve effectiveness of random mutagenesis, and provides a possible solution to engineering membrane protein with complicated evolutionary fitness landscapes, which can be difficult for classic enzyme engineering approaches.

Fully Conjugated Microporous Polymers as Metal-Free Heterogeneous Photocatalysts for Organic Transformations.

Photoactive conjugated microporous polymers (CMPs) have recently received huge attention in photocatalytic organic transformations owing to their adjustable structure and functionality. However, commonly reported CMPs are synthesized through metal catalyzed coupling reactions, which require complicated product separation and result in increased costs. In this study, two sp2 carbon-linked CMPs are constructed by organic base induced Knoevenagel reaction using 2,6-dimethylbenzo[1,2-d:4,5-d']bisoxazole and aromatic polyaldehydes as co-monomers. The new benzobisoxazole-based polymer materials feature fully π-conjugated skeleton with broad visible-light absorption, permanent porosity as well as outstanding stability. Importantly, they can effectively induce many organic reactions such as C-3 thiocyanation of indoles under visible-light illumination and show broad substrate applicability and superior recyclability.

One-ElectronNO to N2O Pathways via Heme Models and Lewis Acid: Metal Effectsand Differences from the Enzymatic Reaction.

Some pathogens use heme-containing nitric oxide reductases (NORs) to reduce NO to N2O as their defense mechanism to detoxify NO and reduce nitrosative stress. This reduction is also significant in the global N cycle. Our previous experimental work showed that Fe and Co porphyrin NO complexes can couple with external NO to form N2O when activated by the Lewis acid BF3. A key difference from conventional two-electron enzymatic reaction is that one electron is sufficient. However, a complete understanding of the entire reaction pathways and the more favorable reactivity for Fe remains unknown. Here, we present a quantum chemical study to provide such information. Our results confirmed Fe's higher experimental reactivity, showing advantages in all steps of the reaction pathway: easier metal oxidation for NO reduction and N-O cleavage as well as a larger size to expedite the N/O coordination mode transition. The Co system, with a similar product energy as the enzyme, shows potential for further development in catalytic NO coupling. This work also offers the first evidence that this new one-electron NO reduction is both kinetically competitive and thermodynamically more favorable than the native pathway, supporting future initiatives in optimizing NO reduction agents in biology, environment, and industry.

Promotion of Metal‐Free Catalytic Coupling of Fluorinated Halogenated Hydrocarbons By a Base for the Synthesis of Difluoromethyl Heterocyclic Amines

The selective functionalization of difluoromethyl groups (‐CF2) is a promising approach and an attractive synthetic route for accessing fluorine‐containing moieties with medicinal benefits. Here, we report a case of a C‒N coupling reaction between bromodifluoropropene with heterocyclic amines, such as indole, pyrrole, and imidazole, promoted by an alkali without the use of transition metal catalysis. This reaction differs from existing methods in that it does not undergo a difluoromethylation isomerization reaction but directly retains the structure of the terminal olefin. This chemical conversion process has a wide substrate range, good functional group tolerance, and an ideal reaction conversion rate, making it an effective new method for the difluoropropenation of heterocyclic amines.

Unraveling the Synergy of Au and Polar MgO(111) Surface in Photothermal Catalytic Oxidative Coupling of Methane

AbstractDirect and selective catalytic oxidative coupling of methane (OCM) into high‐carbon products is a great challenge in C1 chemistry. Herein, the successful fabrication of a series of Au clusters loaded on different MgO facets of (111), (110), and (100) is reported. This work demonstrates the Au‐loaded MgO(111) (denoted as Au/MgO(111)) shows the highest C2H6 yield of 12733.4 µmol g−1 h−1 and selectivity of 90.4%, which is 2.46 times higher than that of Au/MgO(110) (5171.4 µmol g−1 h−1) and 25.14 times higher than that of Au/MgO(100) (506.4 µmol g−1 h−1). Moreover, the high activity of Au/MgO(111) can be well maintained over 100 h. Detailed in situ experiments and theoretical calculation reveal such great performance can be attributed to 1) the strong electronic affinity of the surface oxygen species on polar MgO(111) and CH4with the lowest adsorption energy of −0.82 eV; 2) the Au/MgO(111) shows the lowest ΔERDS of 0.53 eV in the rate‐deterime step of OCM that comes in activating the second CH4 molecule; 3) the Au can act as a hole acceptor under light irradiation and adsorb *CH3 with a strong d‐σ hybridization, resulting in an increased C2H6 selectivity.

A general rate equation theory for non– and catalytic coupling gas–solid reactions and its application to sorption-enhanced water gas shift

Sorption-enhanced water gas shift (SEWGS) involves the catalytic WGS reaction of CO with H2O and the non-catalytic gas–solid carbonation reaction of CO2 with CaO. This work proposes a first-principal rate equation theory for non– and catalytic coupling gas–solid reactions. The theory starts from quantum chemistry calculation and extends to larger scales to predict SEWGS experiments conducted in the reactor result without any empirical hypothesis. The coupling mechanism of non– and catalytic reactions is illustrated in a mesoscopic way, based on which the kinetic transition behavior and morphology change on the catalyst surface for WGS can be obtained. The hierarchical framework bridges the scale gap between elementary reactions and pilot plants and the prediction results of and gas profile at the exit of the bubbling bed and carbonation conversion are validated by experiments. The multiscale kinetics is promising to apply to non– and catalytic coupling gas–solid reaction kinetics studies.

Design of Oil Mist and Volatile-Organic-Compound Treatment Equipment in the Manufacturing Plant

To effectively confront the acute challenge of global warming, at the present stage, the Chinese government has designated carbon reduction as the core objective to accomplish the coordinated control of greenhouse gas and pollutant emissions. As China is a major manufacturing country, with the continuous improvement of air emission standards, it is particularly necessary to carry out the design of more efficient volatile organic pollutant emission devices. This study takes a treatment system with a waste gas ventilation volume of 6 × 104 m3·h−1 as an example, adopts the end treatment approach of adsorption and catalytic combustion coupling, and designs a purification device composed of multistage oil-mist recovery, electrostatic adsorption, dry filtration, activated-carbon adsorption and desorption, catalytic combustion, etc. It also employs the fuzzy proportional-integral-derivative fine temperature control algorithm, and the temperature overshoot was decreased by 85%. The average emission concentration of volatile organic compounds at the equipment outlet is 6.56 mg·m−3, and the average removal rate is 93.99%, far surpassing the national emission standards. The device operates efficiently and stably, confirming that the end-coupled treatment system based on the adaptive fuzzy proportional-integral-derivative temperature control strategy can effectively handle volatile organic compounds with oil mist and holds significant promotion and research value.

Indolizinylalanine Regioisomers: Tryptophan Isosteres with Bathochromic Fluorescence Emission.

We have developed a high yielding synthesis of indolizine and directly elaborated the molecule into three optically active indolizinylalanine regioisomers. The protocols exploit metal catalyzed coupling of indolizinyl-halides with organozinc reagents derived from carbamoylated iodoalanine esters. The scalable protocols provide products in a form amenable to solid-phase peptide synthesis (SPPS). When incorporated into peptides, the indolizine heterocycle is more basic and markedly less nucleophilic than tryptophan. Its protonated vinylpyridinium form is deeply colored in solution while the neutral heterocycle is highly fluorescent. The fluorescence quantum yield of indolizine exceeds that of indole and aza-indoles in water, suggesting that indolizinylalanines could be powerful optical probes of protein structure and dynamics, functioning as true tryptophan isosteres.

Synthesis of acrylic acid and acrylates from CO<sub>2</sub> and ethylene — the thorny path from dream to reality

The development of atom-economical and efficient processes for obtaining a variety of chemical products using CO<sub>2</sub> as C<sub>1</sub>-synthon plays an increasingly important role in modern scientific and technological research. Due to the inertness of CO2 many extremely attractive routes to valuable chemical products turn out to be impossible to implement, particularly for thermodynamic reasons, leaving one only dreaming about them as something unattainable. This review demonstrates how the catalytic coupling of ethylene and CO<sub>2</sub> into acrylic acid, once considered a "dream reaction" has not only become a reality, but has also evolved into the category of technological processes. The key stages of the long-term development of this unique reaction from the discovery of metal activation of CO<sub>2</sub> and stoichiometric preparation of metallalactones to catalytic synthesis using a variety of metal-catalysts (Ni, Pd, Ru, Rh) showcase the ingenuity and skill of researchers as well as an example of consistent development in this field of chemistry. We believe that this remarkably successful example will inspire scientists to tackle any "impossible" problems.<br> The bibliography includes 117 references.

Novel catalytic membrane based on γ-FeOOH@PVDF/peroxymonosulfate for efficient ammonia recovery: Self-cleaning mechanism and emerging organic contaminant degradation performance

The resolution of membrane fouling issues is crucial for the commercial application of membrane distillation (MD) ammonia recovery. The peroxymonosulfate-based advanced oxidation process (PMS-AOP) exhibited conspicuous degradation of organic pollutants, and in-situ coupling with the MD process could probably achieve desirable antifouling performance. In this research, a novel γ-FeOOH@PVDF catalytic membrane was fabricated by gas–liquid self-deposition method and fluorination treatment. The γ-FeOOH nanosheets arrayed on the substrate membrane endowed the catalytic membrane with superhydrophobicity. The MD ammonia recovery of the digestate achieved a high recovery rate (97.3%), and no membrane fouling or wetting phenomena were detected by real-time monitoring by optical coherence tomography (OCT). The batch degradation experiments of thiamphenicol (TAP) validated the γ-FeOOH@PVDF/PMS system with superior degradation performance and stability. The electron paramagnetic resonance (EPR) coordinated free radical quenching experiment determined the active substance (SO4•-, 1O2, O2•- and •OH) in the degradation process. In addition, the potential self-cleaning mechanism of the radical and non-radical pathways of γ-FeOOH@PVDF was elucidated via density functionaltheory (DFT) calculation. The quinone groups in the organic pollutants facilitated the redox of Fe(Ⅲ)/Fe(Ⅱ) and accelerated the activation of PMS. Hence, the catalytic membrane developed in this research provided a novel instructive strategy for membrane fouling control and also exhibited significant potential of coupling catalysis and membrane technology for water treatment.

The Catalytic Coupling of CO2 and Glycidol toward Glycerol Carbonate

The Catalytic Coupling of CO₂ and Glycidol toward Glycerol Carbonate

Sludge biochar accelerates transformative phenolic compounds removal from wastewater via the coupling mechanism

In this work, we investigated the mechanism of the oxidation of phenolic compounds (PCs) by graphitic sludge biochar (SDBCs) via a catalytic coupling regime in the presence of potassium persulfate (PDS). In-situ synchrotron attenuated total reflection Fourier transform infrared spectroscopy (in-situ ATR-FITR) combined with Raman spectroscopy directly monitored the formation of SDBC-PDS* complexes, which drove the electron-transfer pathway as evidenced by electrochemical tests and galvanic cell experiments. The coupling of pollutants into oligomers effectively reduced total organic carbon in water with a low PDS usage (PDS consumption to phenol degradation ratio of 2.2). Furthermore, our research showed that the biochar-based nonradical system effectively treats various PCs, with oxidation rates related to their half-wave potential and Hammett constant. Overall, this work explored sludge biochar engineering, PCs transformation and interfacial coupling mechanism, providing a novel approach for the efficient and cost-effective treatment of phenolic wastewater with low chemical input.