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[Display omitted] • A cobalt-catalyzed direct alkoxycarbonylation of ethers. • A variety of phenols and alcohols were transformed to the corresponding α -oxy ester derivatives in high yields with excellent functional group tolerance. • Several pharmaceutical and bioactive molecule related compounds were also suitable substrates here. A cobalt-catalyzed direct alkoxycarbonylation of ethers has been accomplished. This new catalytic system allows the use of ethers, important building blocks in organic synthesis, as the carbonylation substrates. A variety of phenols and alcohols were transformed to the corresponding α -oxy ester derivatives in high yields with excellent functional group tolerance. In addition, several pharmaceutical and bioactive molecule related compounds were also suitable substrates for this carbonylation process, the target products were obtained in good yields. [ABSTRACT FROM AUTHOR]

This review discusses the importance of mitigating CO 2 emissions by valorizing CO 2 through high-pressure catalytic processes. It focuses on various key processes, including CO 2 methanation, reverse water-gas shift, methane dry reforming, methanol, and dimethyl ether synthesis, emphasizing pros and cons of high-pressure operation. CO 2 methanation, methanol synthesis, and dimethyl ether synthesis reactions are thermodynamically favored under high-pressure conditions. However, in the case of methane dry reforming and reverse water-gas shift, applying high pressure, results in decreased selectivity toward desired products and an increase in coke production, which can be detrimental to both the catalyst and the reaction system. Nevertheless, high-pressure utilization proves industrially advantageous for cost reduction when these processes are integrated with Fischer-Tropsch or methanol synthesis units. This review also compiles recent advances in heterogeneous catalysts design for high-pressure applications. By examining the impact of pressure on CO 2 valorization and the state of the art, this work contributes to improving scientific understanding and optimizing these processes for sustainable CO 2 management, as well as addressing challenges in high-pressure CO 2 valorization that are crucial for industrial scaling-up. This includes the development of cost-effective and robust reactor materials and the development of low-cost catalysts that yield improved selectivity and long-term stability under realistic working environments. [Display omitted] [ABSTRACT FROM AUTHOR]

A general and efficient protocol based on palladium-catalyzed intramolecular cyclization and reductive aminocarbonylation of iodoarene-tethered propargyl ethers and nitroarenes for the synthesis of acetamide-functionalized benzofurans has been explored. [Display omitted] • A straightforward palladium-catalyzed cyclization/carbonylation reaction of iodoarene-tethered propargyl ethers for the synthesis of acetamides-functionalized benzofurans has been developed. • Nitroarenes has been applied as the nitrogen sources and Mo(CO) 6 played a dual role as both CO precursor and reductant. • A variety of acetamides-functionalized benzofurans were prepared in good yields with very good substrate tolerance. A general and efficient protocol based on palladium-catalyzed intramolecular cyclization and reductive aminocarbonylation reaction for the synthesis of acetamide-functionalized benzofurans has been explored. The reaction using iodoarene-tethered propargyl ethers and nitroarenes as the starting materials. This reaction features the formation of structure defined benzofurans with acetamides as attractive functional groups in a single step operation. By using Mo(CO) 6 as both CO source and reductant, a variety of acetamides-functionalized benzofurans were obtained in moderate to good yields with good functional group compatibility. [ABSTRACT FROM AUTHOR]

[Display omitted] • The sulfur vacancies (SVs) could be generated on ultrathin CdS nanosheet (CdS-NS) through visible light irradiation. • The light-induced SVs on CdS-NS can function as typical Lewis acid sites to adsorb and activate silanes. • Photocatalytic dehydrogenative coupling of silanes with alcohols has been achieved on CdS-NS with in-situ generated SVs. Photocatalytic organosilicon transformation is a green and emerging synthetic strategy toward silyl ethers production. This approach takes advantage of the highly reactive photogenerated electron-hole pairs to trigger redox reactions for chemical transformations under mild conditions. However, the development of heterogenous photocatalysts for silyl ethers synthesis is greatly hampered by the lack of sufficient reactive sites on the catalyst surface for the adsorption and activation of silanes. Herein, we demonstrate that the light-induced sulfur vacancies (SVs) in-situ generated on ultrathin CdS nanosheet (CdS-NS) can function as typical Lewis acid sites to adsorb and activate silanes via the formation of Si H···Cd coordination species. In addition, these electron-deficient SVs can also trap the photogenerated electrons to promote charge separation. The CdS-NS with SVs exhibits an excellent photocatalytic performance toward silyl ethers synthesis while producing H 2 simultaneously. This synthetic strategy based on in-situ creation of abundant Lewis acid sites on photocatalyst surface to activate silanes will have broad implications in the development of high-performance photocatalysts for organosilicon transformations. [ABSTRACT FROM AUTHOR]

Dimethyl ether carbonylation to methyl acetate was studied on a series of dealuminated mordenites with Si/Al ratios of 6.5 through 15.4. Dealumination was achieved via leaching with nitric acid. Selective coupled removal of T3 and T4 Al sites located in 4-membered rings in 8- and 12-membered channels, respectively, was suggested by a combination of DRIFTS, TPD of probe molecules, 27 Al MAS NMR, surface area, pore distribution, and XRD analyses. The methyl acetate peak productivity was found to be equal when calculated per residual T3 sites in 8-membered rings, providing experimental evidence of the reaction site specificity. While dealumination led to the decrease in product peak rate because of active and selective T3 site removal, it doubled the catalyst lifetime and increased selectivity upon deactivation from 50% to 80%. The study decoupled the contribution of 4-membered (T3 and T4) and 5-membered (T1 and T2) acid sites to the products’ formation and catalyst deactivation. [ABSTRACT FROM AUTHOR]

This paper reports on direct dimethyl ether synthesis from syngas on hybrid bifunctional copper–zeolite catalysts. Both laboratory synthesized and commercial zeolites were used in this work. The catalyst performance is evaluated under pressure in a continuous fixed bed milli-reactor. The relationships between zeolite particle sizes, acidity and catalytic performance of the hybrid catalysts in dimethyl ether synthesis have been studied. The catalysts and catalyst precursors were characterized using a wide range of characterization techniques: nitrogen adsorption–desorption measurements, X-ray diffraction, 27 Al NMR, scanning electron microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy with adsorbed molecular probes. It is found that the reaction rate in direct dimethyl ether synthesis is strongly affected by the sizes of zeolite particles. The hybrid catalysts containing small individual nanosized zeolite particles (60–100 nm) were much active than their counterparts with intergrown crystal agglomerates. The phenomenon is interpreted in terms of enhanced transport of methanol from the copper catalyst to the acid sites in the small zeolite particles with a shift of the thermodynamic equilibrium. The catalyst deactivation was attributed to copper sintering in the presence of the acid sites on the external surface of zeolites. It is established that the catalyst deactivation is less significant with the catalysts containing ZSM-5 zeolites with lower concentration of acid sites on the zeolite external surface. A new methodology to enhance the catalytic performance and stability of copper–zeolite hybrid catalysts for direct dimethyl ether synthesis is proposed. [ABSTRACT FROM AUTHOR]

Direct synthesis of dimethyl ether (DME) from syngas was investigated over a series of hybrid catalytic systems containing a Cu-based methanol synthesis component with varying amounts of ZnO and MgO, and γ-Al 2 O 3 as a methanol dehydration component. Methanol synthesis and methanol dehydration components were homogeneously mixed in a 2:1 weight ratio to prepare the hybrid catalysts, which were characterized by transmission electron microscopy, scanning electron microscopy, BET surface area analysis, powder X-ray diffraction, NH 3 temperature-programmed desorption, and H 2 temperature-programmed reduction methods. The syngas-to-DME (STD) reaction was studied in an isothermal fixed bed reactor at 30 bar and 260 °C. The catalysis results revealed improved effectiveness of the catalyst in the presence of 20 mol% MgO, enabling a significant enhancement in CO conversion from 19% to 37% and in DME selectivity from 36% to 83%, as compared with the activity of a catalyst without MgO. By-product CO 2 and C 1 and C 2 hydrocarbon selectivity was also decreased from 48% to 14% for CO 2 and from 8% to 2.5% for hydrocarbons. Catalyst performance, CO conversions and DME selectivity were evaluated by varying the reaction temperature, pressure, space velocity and H 2 /CO ratio in syngas. XRD data revealed the formation of a good crystalline malachite structure for the catalysts containing up to 20 mol% MgO, but the crystallinity in the structure was lost when 30% MgO was added, resulting in decreased catalytic activity. [ABSTRACT FROM AUTHOR]

-Highlights: [•] TiO2-supported HPAs are very active for low-temperature DME production. [•] H2O molecules between Keggin units on HPA/TiO2 are weakly bonded leading higher reaction rates. [•] The acidity of HPAs and HPA/TiO2 is very strong. [•] The Keggin structure is stable upon deposition on TiO2 until ca. 723K. [ABSTRACT FROM AUTHOR]

Highlights: [•] Acid resins are effective catalysts for ethyl octyl ether synthesis in liquid phase. [•] Alcohols conversion increases with the acid capacity of the resins. [•] Selectivity to ethyl octyl ether is greatly influenced by V sp and [H+]/V sp. [•] The swollen morphology is a very significant factor in ethyl octyl ether synthesis. [•] A fraction of acid sites does not take part in EOE synthesis in high cross-linked resins. [ABSTRACT FROM AUTHOR]

Keggin heteropolyacids were immobilized on functionalized silica as their onium (γ-propyl-N-pyridinium, γ-propyl-N-methyl and γ-propyl-N-butyl-imidazolium) salts. Interaction between HPA and the surface-grafted onium cations affords acid salts. In contrast to bare silica, impregnated with HPA, these materials have monoanionic dispersions of HPA on the surface and superior resistance to HPA leaching in polar media. The greatest stability of the Keggin structure and resistance to leaching were found for H4SiW12O40–(SiW)-, and the lowest for H3PMo12O40–(PMo)-based samples. In the two model reactions tested, the liquid-phase synthesis of ETBE and the esterification of AcOH with EtOH, these solids display good catalytic performance (activity per anion, up to 150 and 25 h−1, respectively) and relative high structural stability. Catalysts having a greater coverage of organic functions (revealed by comparing two pyridinium salts) and hydrophobic cations (by comparing two imidazolium salts) have the best performance. Amongst the heteropolyacids studied, H4SiW12O40 is the most active and promising for catalyst design. [Copyright &y& Elsevier]

Abstract: In this paper, a novel technique combined light-electronic microscopy and computer imaging trace was used to investigate the synthesis of thioether, which is an intermediate for lansoprazole. The reaction kinetics study by a visualization technique was carried out in a minireactor, and the concentration–grayscale standard curves for thioether were obtained by analyzing the grayscales of digital images for the solutions with 20 different concentrations. Based on the concentration–grayscale standard curves, the reactant concentrations at different times were calculated and the reaction kinetic curve as well as the reaction rate equation were obtained. It was found that the total mass-transfer resistance of sodium imidazole was larger than that of bromopyridine. Liquid–liquid interface of synthesizing thioether was observed and its mass transfer mechanism was discussed. [Copyright &y& Elsevier]

Based on a flexible ether-oxygen tricarboxylate ligand, H 3 L ​= ​3,5-bis[(3-carboxylphenyl)oxy]benzoic acid, one novel 2-D La-CP with the formula of {[La(L)(H 2 O) 3 ]·H 2 O} n has been solventhermally synthesized. The 2-D bilayer structure of La-CP is constructed by carboxylate-bridged La n (CO 2) n layers connected by M-shaped tricarboxylate ligands arranged below and above, respectively. The La-CP exhibits blue luminescence and demonstrates multi-responsive luminescence sensing activities toward Fe3+, Cr(VI) and benzothiazoles (BTs) through luminescence quenching. It could be repeated after at least five cycling runs. The fast response, high sensitivity and selectivity makes it a potential multi-functional chemosensor. A novel multi-functional chemosensor of La-CP exhibits blue luminescence and demonstrates multi-responsive luminescence sensing activities toward Fe3+, Cr(VI) and benzothiazoles (BTs) through luminescence quenching. Image 1 [ABSTRACT FROM AUTHOR]