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The solvent effect on H-BEA catalyzed cyclohexanol dehydration was investigated in water, dioxane, and cyclohexanol. The dynamic evolution of the Brønsted acid site of zeolite and its interaction with reactant molecules in different solvents were explored with ab initio molecular dynamics simulations, providing reliable configuration sampling to obtain configurations at equilibrium. Solvent profoundly changes the adsorption as well as the dehydration reaction of cyclohexanol in H-BEA, where the reaction is determined to follow the E2 mechanism in water and dioxane but the E1 mechanism in cyclohexanol untill saturation uptake. Near saturation uptake, all three solvents significantly reduce the cyclohexanol dehydration rates in H-BEA. Cyclohexanol loading also dramatically affects the kinetics of the dehydration reaction, displaying an overall decreasing trend with a local minimum present at intermediate loading of 6 molecules per unit cell, which is a result of the entropic effect associated with greater freedom of motion of the transition state. Rigorous quantification of enthalpy and entropy contributions to cyclohexanol adsorption and activation shed light on the solvent effect of zeolite-catalyzed alcohol dehydration. [ABSTRACT FROM AUTHOR]

In the liquid phase of heterogeneous catalysis, solvent plays an important role and governs the kinetics and thermodynamics of a reaction. Although it is often difficult to quantify the role of the solvent, it becomes particularly challenging when a zeolite is used as the catalyst. This difficulty arises from the complex nature of the liquid/zeolite interface and the different solvation environments around catalytically active sites. Here, we use ab initio molecular dynamics simulations to probe the local solvation structure and dynamics of methanol and water over MWW zeolite nanosheets with varying Brønsted acidity. We find that the zeolite framework and the number and location of the acid sites in the zeolite influence the structure and dynamics of the solvent. In particular, methanol is more likely to be in the vicinity of the aluminum (Al3+) at the T4 site than at T1 due to easy accessibility. The methanol oxygen binds strongly to the Al at the T4 site, weakening the Al–O for the bridging acid site, which results in the formation of the silanol group, significantly reducing the acidity of the site. The behavior of methanol is in direct contrast to that of water, where protons can easily propagate from the zeolite to the solvent molecules regardless of the acid site location. Our work provides molecular-level insights into how solvent interacts with zeolite surfaces, leading to an improved understanding of the catalytic site in the MWW zeolite nanosheet. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Lewis base catalyzed and Brønsted acid controlled chemodivergent electrophilic selenofunctionalizations of alkynes were developed for the first time. Various selenium‐containing tetrasubstituted alkenes were readily obtained in moderate to excellent yields with complete E/Z selectivities. As the substrates were 1‐ethynyl naphthol derivatives, linear selenium‐containing tetrasubstituted alkenes were produced via intermolecular oxygen nucleophilic attack in the absence of acid additive; in contrast, cyclic selenium‐containing tetrasubstituted alkenes were generated through intramolecular carbon nucleophilic capture with the addition of Brønsted acid. [ABSTRACT FROM AUTHOR]

The highly strained bicyclo[1.1.0]butanes (BCBs) have exhibited excellent synthetic value and have attracted increasing attention in the field of organic synthesis. However, the mechanism of the activation of such materials under organocatalysis has been studied little. In the present study, the mechanism and origin of stereoselectivity for a chiral Brønsted acid (CBA)-catalyzed isomerization reaction of BCB were systematically investigated using the DFT method. Based on computational results, the β-H elimination step is the stereoselectivity-determining step, through which the S-configured product is generated preferentially. Furthermore, non-covalent interaction (NCI) and atom-in-molecule (AIM) analyses were performed to disclose the origin of the stereoselectivity and show the relatively many and strong noncovalent interactions to be the key for stabilizing the S-configured transition state and thus inducing the stereoselectivity. [ABSTRACT FROM AUTHOR]

The experimentally obtained kinetic data has indicated the existence of a synergetic cocatalytic effect provided by an iodonium salt in the base‐catalyzed Knoevenagel condensation. The diphenyliodonium triflate serving as the halogen bond‐donating Lewis acid provides the higher cocatalytic effect than zinc(II) triflate or triflic acid serving, respectively, as the metal cation‐based Lewis acid and Brønsted acid. Such a cocatalytic effect remains the same for a broad scope of carbonyl compounds covering aldehydes featuring electron‐withdrawing or electron‐donating substituents, as well as ketone involved in the reaction. [ABSTRACT FROM AUTHOR]

Lignocellulosic biomass (LCB) is an abundant renewable energy resource. Hence, the conversion of biomass into fuel and platform chemicals has recently attracted considerable attention. Furfural is an important platform product that can be produced from xylan-rich lignocellulosic biomass. Hemicellulose undergoes two stages, hydrolysis and dehydration, resulting in the production of furfural. In this review, one-step and two-step strategies for furfural production and the subsequent techno-economic evaluation of the integration of furfural and other co-products are presented. The direct one-step production of furfural requires a one-time investment in severe pretreatment conditions or the use of more chemicals, whereas the two-step production requires the separation of additional prehydrolysates, followed by more drastic treatment conditions. In both strategies, water flow, steam flow, organic solvents, deep eutectic solvents (DESs) or ionic liquids (ILs) can be used as solvent phases to hydrolyze hemicellulose. Lewis acid and Brønsted acid catalysts can effectively convert hemicellulose-derived pentose into furfural. A biphasic solvent system can effectively prevent the degradation of furfural in water, thus increasing the yield and selectivity of furfural. The techno-economy assessment results indicate that biorefineries are transitioning to adopting an integrate model of co-production of furfural and other products. Alternative green approaches are increasingly being adopted to make the furfural industry more sustainable and profitable. [ABSTRACT FROM AUTHOR]

A hydrosulfonylation reaction of unactivated alkenes with sulfinic acids was realized under light irradiation. This reaction features photocatalyst- and additive-free conditions. A diverse set of unactivated alkenes can be transformed into alkyl-substituted sulfones with good yields and anti-Markovnikov regioselectivity. The present protocol was amenable to gram-scale synthesis, as well as late-stage modification of drugs and natural products. Preliminary mechanistic studies on UV-visible light absorption suggested the key role of sulfinic acid as a light-absorbing species. DFT calculations also shed light on the mechanism of this reaction, which may involve a radical chain pathway. [ABSTRACT FROM AUTHOR]

Development of a simple and efficient catalytic system is significant for the synthesis of 1,3-diynes in organic synthesis. Herein, an acidic mesoporous ZSM-5-supported Pd catalyst (Pd@MZSM-5) was able to transform terminal alkynes into 1,3-diynes without any additive under an oxygen atmosphere. The Brønsted acid sites in the Pd@MZSM-5 catalyst could promote the adsorption of alkynes through the interaction of the CRC bond with the hydroxyl group, which benefits the active Pd2+ species bonding with the CRC bond to form the alkynyl-palladium(II) complex. This complex underwent a reductive elimination process to form the 1,3-diyne product. [ABSTRACT FROM AUTHOR]

A mild protocol for hydroacylation of enones through photosensitization of acyl silanes with thioxanthone under blue light (455 nm) irradiation is reported. A Brønsted acid is used as a cocatalyst in the reaction. The versatility of the method is demonstrated through inter‐ and intramolecular hydroacylation reaction. The hydroacylation product is applied for synthesizing an anti‐HCV agent. Mechanistic insights are also provided through control experiments. [ABSTRACT FROM AUTHOR]

This article presents a new method for synthesizing α-quaternary carbaldehydes through the chemoselective House-Meinwald rearrangement of trisubstituted epoxides. The authors used Brønsted acids as catalysts and identified optimal reaction conditions. The method allows for the synthesis of various carbaldehydes and has been validated for stereospecific reactions. The authors suggest that this method could be useful in the total synthesis of natural products. [Extracted from the article]

This article discusses the synthesis of nitrogen-containing heterocycles, which are important in organic chemistry and medicinal chemistry. The authors focus on the enantioselective (3+2)-annulation of β-keto esters with azoalkenes to form bicyclic dihydropyrroles. They propose a cooperative catalysis strategy using a chiral Pd-aqua complex and a Brønsted acid to activate both the nucleophile and the electrophile. The authors successfully demonstrate the synthesis of these heterocycles with high yields and excellent enantioselectivity. [Extracted from the article]

In this paper, the foam-like multi-stage porous 3wt%Al-KIT-6-4T(WI) catalyst was prepared and employed for efficient catalyzing biomass-derived GVL to butene. It is found that the prepared 3wt%Al-KIT-6-4T(WI) catalyst possess abundant mesoporous and presented the foam-like microstructure. Due to this, the 3wt%Al-KIT-6-4T(WI) catalyst has large specific surface area (517.09 m2·g−1) and adequate amount of surface acid sites (both Brønsted and Lewis acid site). The special microstructure further improves the mass transfer efficiency of reactants and products. Under the optimized reaction conditions, the butene yield over the 3wt%Al-KIT-6-4T(WI) catalyst can up to 93.78% at 300 °C, after reacting 240 min. Moreover, the 3wt%Al-KIT-6-4T(WI) catalyst still showed excellent regeneration stability, and above 72% butene yield can be maintained after 7th cycle tests. [ABSTRACT FROM AUTHOR]

This work presents a comprehensive investigation of novel organic dyes MD‐1‐2 as active acid and base co‐sensitizers in dye‐sensitized solar cells (DSSCs), using well‐known Ru(II)‐based N3 dyes. These co‐sensitizers contain a triphenylamine ring as a donor scaffold linked with an electron‐withdrawing cyanopyridyl and cyano benzoic acid acceptor for MD‐1‐2. In this study, we demonstrated the significant impact of base dyes with pyridine anchoring units on the photovoltaic parameters of N3‐sensitized devices. This methodology takes advantage of the ability of carboxyl and pyridyl moieties to interact with the Brønsted acid and Lewis acid sites on TiO2 surfaces, respectively. By reducing competition between dyes for surface binding, dye packing density on the TiO2 is enhanced while electron recombination is minimized, leading to higher photovoltage. Furthermore, the influence of varying sensitizer/co‐sensitizer ratios was comprehensively studied. Outcomes showed devices made using co‐sensitizer MD‐1‐2 with sensitizer N3 at all relative concentrations surpassed those with only N3. Importantly, the co‐sensitized devices that were made utilizing 0.3 mM acid–base MD‐1 and N3 sensitizer had the greatest solar energy capacity. It had a power conversion efficiency of 10.35%, a short‐circuit current density of 20.01 mA·cm−2, and an open‐circuit voltage of 752 mV. The results provide fresh insight into optimizing devices to create DSSCs with improved efficiency by choosing acceptable co‐sensitizers at suitable concentrations. [ABSTRACT FROM AUTHOR]

The tacticity of vinyl polymers is a key factor affecting the properties of materials. Recently, organic Brønsted acids have been demonstrated as effective catalysts for the development of highly stereoselective cationic reversible addition-fragmentation chain transfer (RAFT) polymerizations of vinyl ethers, in which the use of RAFT agents could allow the control the molecular weight and tacticity of polymer products simultaneously. However, the effect of RAFT agents on the tacticity-regulation remains elusive and lacks of investigation. In this study, we synthesized four types of RAFT agents and evaluated their influence in the stereoselective cationic polymerization of isobutyl vinyl ether in the presence of PADI as a Brønsted acid catalyst, which unveils that the Z group of RAFT agents could not only affect the polydispersity of the products, but also exert a profound effect on the stereoselectivity. After extensive screening of the RAFT agents, high stereoregularity (isotacticity, 90% m) was obtained when using dithiocarbonate ester-type RAFT agents with a benzyloxy Z group. [ABSTRACT FROM AUTHOR]

Solid Brønsted acid catalysts are crucial heterogeneous catalysts used as substitutes for liquid Brønsted acids in organic synthesis. In this research, solid Brønsted acid was synthesised in an easy and environmentally friendly method using rice husks as a raw material by converting them to dissolved sodium silicate and using sol–gel technique, silylating agents ((3-chloropropyl)triethoxysilane (CPTES)) reacted with sodium silicate to prepare RH-SiO2PrCl. Through the nucleophilic reaction between RH-SiO2PrCl and 1-Amin-2-naphthol-4-sulfonic acid, a solid acid catalyst (RH-SiO2PrANSA) was prepared. The solid acid catalyst is characterized by many techniques, such as FTIR, EDX, CHNS, and BET. The results showed a secondary amine absorption band (–N–H) at 3236 cm−1. Also, the BET results for the catalyst indicated that its surface area was 61.74 m2 g−1 with an average pore diameter of 5.14 nm. The synthesized solid Bronsted acid was used as a catalyst to prepare 2,4,5-Trisubstituted imidazole derivatives by reacting six different subtenant aldehydes with benzil and ammonium acetate. All the products are characterized by FTIR, H NMR, and Mass spectroscopy, with around ~ 90% conversion yields. [ABSTRACT FROM AUTHOR]

This study introduces a novel approach for synthesizing Benzoxazine‐centered Polychiral Polyheterocycles (BPCPHCs) via an innovative asymmetric carbene‐alkyne metathesis‐triggered cascade. Overcoming challenges associated with intricate stereochemistry and multiple chiral centers, the catalytic asymmetric Carbene Alkyne Metathesis‐mediated Cascade (CAMC) is employed using dirhodium catalyst/Brønsted acid co‐catalysis, ensuring precise stereo control as validated by X‐ray crystallography. Systematic substrate scope evaluation establishes exceptional diastereo‐ and enantioselectivities, creating a unique library of BPCPHCs. Pharmacological exploration identifies twelve BPCPHCs as potent Nav ion channel blockers, notably compound 8 g. In vivo studies demonstrate that intrathecal injection of 8 g effectively reverses mechanical hyperalgesia associated with chemotherapy‐induced peripheral neuropathy (CIPN), suggesting a promising therapeutic avenue. Electrophysiological investigations unveil the inhibitory effects of 8 g on Nav1.7 currents. Molecular docking, dynamics simulations and surface plasmon resonance (SPR) assay provide insights into the stable complex formation and favorable binding free energy of 8 g with C5aR1. This research represents a significant advancement in asymmetric CAMC for BPCPHCs and unveils BPCPHC 8 g as a promising, uniquely acting pain blocker, establishing a C5aR1‐Nav1.7 connection in the context of CIPN. [ABSTRACT FROM AUTHOR]

The Fischer–Tropsch synthesis (FTS) reaction is widely used to produce clean hydrocarbon fuels or chemicals. The key challenge for FTS is the control of product distributions. Herein, iron was employed as the active species, and the supported (Fe/S1 and Fe/S2) and encapsulated (Fe@S1 and Fe@S2) catalysts with pure siliceous zeolite were successfully prepared by incipient wetness impregnation and solvent-free hydrothermal method, respectively. The iron species encapsulated in silicalite zeolite, rather than being present on the surface, enhanced the acidity of zeolite, which was effective in regulating the FTS products. The acidic site can be divided into two types: Lewis and Brønsted, where the Brønsted acid sites are much more stable than Lewis acid sites at FTS reaction temperature. Moreover, Fe@S1 and Fe@S2 with much more Brønsted acid sites displayed a higher selectivity of isoparaffins in the FTS products compared to the supported catalysts (17.6% and 18.6% for Fe@S1 and Fe@S2 vs. 4.1% and 11.8% for Fe/S1 and Fe/S2, respectively). Thus, the acidity of silicalite zeolite can be regulated by encapsulating active metal in it, which is a promising prospect for tuning production distribution in FTS reactions. [ABSTRACT FROM AUTHOR]

This study introduces a novel approach for synthesizing Benzoxazine‐centered Polychiral Polyheterocycles (BPCPHCs) via an innovative asymmetric carbene‐alkyne metathesis‐triggered cascade. Overcoming challenges associated with intricate stereochemistry and multiple chiral centers, the catalytic asymmetric Carbene Alkyne Metathesis‐mediated Cascade (CAMC) is employed using dirhodium catalyst/Brønsted acid co‐catalysis, ensuring precise stereo control as validated by X‐ray crystallography. Systematic substrate scope evaluation establishes exceptional diastereo‐ and enantioselectivities, creating a unique library of BPCPHCs. Pharmacological exploration identifies twelve BPCPHCs as potent Nav ion channel blockers, notably compound 8 g. In vivo studies demonstrate that intrathecal injection of 8 g effectively reverses mechanical hyperalgesia associated with chemotherapy‐induced peripheral neuropathy (CIPN), suggesting a promising therapeutic avenue. Electrophysiological investigations unveil the inhibitory effects of 8 g on Nav1.7 currents. Molecular docking, dynamics simulations and surface plasmon resonance (SPR) assay provide insights into the stable complex formation and favorable binding free energy of 8 g with C5aR1. This research represents a significant advancement in asymmetric CAMC for BPCPHCs and unveils BPCPHC 8 g as a promising, uniquely acting pain blocker, establishing a C5aR1‐Nav1.7 connection in the context of CIPN. [ABSTRACT FROM AUTHOR]

As the Brønsted acid sites in the 8-membered ring (8-MR) of mordenite (MOR) are reported to be the active center for dimethyl ether (DME) carbonylation reaction, it is of great importance to selectively increase the Brønsted acid amount in the 8-MR. Herein, a series of Fe-HMOR was prepared through one-pot hydrothermal synthesis by adding the EDTA–Fe complex into the gel. By combining XRD, FTIR, UV–Vis, Raman and XPS, it was found that the Fe atoms selectively substituted for the Al atoms in the 12-MR channels because of the large size of the EDTA–Fe complex. The NH3-TPD and Py-IR results showed that with the increase in Fe addition from Fe/Si = 0 to 0.02, the Brønsted acid sites derived from Si-OH-Al in the 8-MR first increased and then decreased, with the maximum at Fe/Si = 0.01. The Fe-modified MOR with Fe/Si = 0.01 showed the highest activity in DME carbonylation, which was three times that of HMOR. The TG/DTG results indicated that the carbon deposition and heavy coke formation in the spent Fe-HMOR catalysts were inhibited due to Fe addition. This work provides a practical way to design a catalyst with enhanced catalytic performance. [ABSTRACT FROM AUTHOR]

The hydrogenolysis of oxygenates such as alcohols and ethers is central to the biomass valorization and also a valuable transformation in organic synthesis. However, a mild and efficient catalyst system for the hydrogenolysis of a large variety of alcohols and ethers with various functional groups is still underdeveloped. Here, we report an aluminum metaphosphate‐supported Pt nanoparticles (Pt/Al(PO3)3) for the hydrogenolysis of a wide variety of primary, secondary, and tertiary alkyl and benzylic alcohols, and dialkyl, aryl alkyl, and diaryl ethers, including biomass‐derived furanic compounds, under mild conditions (0.1–1 atm of H2, as low as 70 °C). Mechanistic studies suggested that H2 induces formation of the surface Brønsted acid sites via its cleavage by supported Pt nanoparticles. Accordingly, the high efficiency and the wide applicability of the catalyst system are attributed to the activation and cleavage of C−O bonds by the hydrogen‐induced Brønsted acid sites with the assistance of Lewis acidic Al sites on the catalyst surface. The high efficiency of the catalyst implies its potential application in energy‐efficient biomass valorization or fine chemical synthesis. [ABSTRACT FROM AUTHOR]

The hydrogenolysis of oxygenates such as alcohols and ethers is central to the biomass valorization and also a valuable transformation in organic synthesis. However, a mild and efficient catalyst system for the hydrogenolysis of a large variety of alcohols and ethers with various functional groups is still underdeveloped. Here, we report an aluminum metaphosphate‐supported Pt nanoparticles (Pt/Al(PO3)3) for the hydrogenolysis of a wide variety of primary, secondary, and tertiary alkyl and benzylic alcohols, and dialkyl, aryl alkyl, and diaryl ethers, including biomass‐derived furanic compounds, under mild conditions (0.1–1 atm of H2, as low as 70 °C). Mechanistic studies suggested that H2 induces formation of the surface Brønsted acid sites via its cleavage by supported Pt nanoparticles. Accordingly, the high efficiency and the wide applicability of the catalyst system are attributed to the activation and cleavage of C−O bonds by the hydrogen‐induced Brønsted acid sites with the assistance of Lewis acidic Al sites on the catalyst surface. The high efficiency of the catalyst implies its potential application in energy‐efficient biomass valorization or fine chemical synthesis. [ABSTRACT FROM AUTHOR]

Doping Mn2+ in newly emerged lead‐free metal halides to access versatile optoelectronic applications is highly desired. However, understanding the chemical pathway of Mn2+ doping and precisely controlling it remains challenging. Here, the crucial role of the initial surface adsorption of Mn2+ in doping kinetics is demonstrated, and the adsorption step is effectively optimized by a moderate Lewis base ligand. The results show that not only the doping concentration of Mn2+ in Cs3Cu2I5 is modulated flexibly but also the produced Cs3Cu2I5:Mn2+ microcrystals exhibit tuned photoluminescence/radioluminescence properties, indicating their applicability in anti‐counterfeiting and X‐ray imaging. Systematic experimental and theoretical outcomes reveal that the moderate Lewis base ligand dually links Mn2+ (hard acid) and Cu+ (soft acid) on the matrix surface, which improves the initial surface adsorption of the dopant and further promotes the doping step. This study contributes a simple strategy for simply controlling Mn2+ doping in Cu(I)‐based halides and also opens a new avenue for understanding the fundamentals of doping dynamics in metal halide systems. [ABSTRACT FROM AUTHOR]

The synthesis of nanosized ZSM-5 zeolites with high crystallinity and suitable acidity is very significant for their great potential in various catalytic applications. Herein, a series of zeolite ZSM-5 crystals with different particle sizes and SiO2/Al2O3 ratios (10-30) were synthesized by a temperature-varying two-step crystallization method in a concentrated gel system containing L-lysine and/or polyvinylpyrrolidone (PVP) additives. By optimizing the addition amounts of the two additives, the crystal size of the ZSM-5 zeolite could be reduced to less than 100 nm. Meanwhile, relatively high crystallinity and framework Al incorporation rates could be achieved, resulting in the generation of high-quality ZSM-5 nanocrystals. The nanosized H-form ZSM-5 zeolite with a SiO2/Al2O3 ratio of 20 showed enhanced catalytic efficiency and stability for the alkylation of 2-methylnaphthalene (2-MN) with methanol to produce an important intermediate, 2,6-dimethylnaphthalene (2,6-DMN). A relatively high and steady yield of 2,6-DMN (above 7.2%) could be achieved during 20 h time-on-stream at 400 °C. The smaller crystal size, higher crystallinity and framework Al content could provide more accessible Brønsted acid sites in the 10-membered ring channel of the ZSM-5 nanocrystals, which are the main active sites responsible for the shape-selectivity of the targeted product of 2,6-DMN. As a result, the formation of other side products like 1-MN and poly-MN could be effectively inhibited, thus leading to an improved 2,6-DMN yield and coke resistance over the nanosized ZSM-5 catalyst. [ABSTRACT FROM AUTHOR]

We have synthesized a quinone‐incorporated bistriarylamine donor‐acceptor‐donor (D–A–D) semiconductor 1 by B(C6F5)3 (BCF) catalyzed C−H/C−H cross coupling via radical ion pair intermediates. Coordination of Lewis acids BCF and Al(ORF)3 (RF=C(CF3)3) to the semiconductor 1 afforded diradical zwitterions 2 and 3 by integer electron transfer. Upon binding to Lewis acids, the LUMO energy of 1 is significantly lowered and the band gap of the semiconductor is significantly narrowed from 1.93 eV (1) to 1.01 eV (2) and 1.06 eV (3). 2 and 3 are rare near‐infrared (NIR) diradical dyes with broad absorption both centered around 1500 nm. By introducing a photo BCF generator, 2 can be generated by light‐dependent control. Furthermore, the integer electron transfer process can also be reversibly regulated via the addition of CH3CN. In addition, the temperature of 2 sharply increased and reached as high as 110 °C in 10 s upon the irradiation of near‐infrared‐II (NIR‐II) laser (1064 nm, 0.7 W cm−2), exhibiting a fast response to laser. It displays excellent photothermal stability with a photothermal (PT) conversion efficiency of 62.26 % and high‐quality PT imaging. [ABSTRACT FROM AUTHOR]

We have synthesized a quinone‐incorporated bistriarylamine donor‐acceptor‐donor (D–A–D) semiconductor 1 by B(C6F5)3 (BCF) catalyzed C−H/C−H cross coupling via radical ion pair intermediates. Coordination of Lewis acids BCF and Al(ORF)3 (RF=C(CF3)3) to the semiconductor 1 afforded diradical zwitterions 2 and 3 by integer electron transfer. Upon binding to Lewis acids, the LUMO energy of 1 is significantly lowered and the band gap of the semiconductor is significantly narrowed from 1.93 eV (1) to 1.01 eV (2) and 1.06 eV (3). 2 and 3 are rare near‐infrared (NIR) diradical dyes with broad absorption both centered around 1500 nm. By introducing a photo BCF generator, 2 can be generated by light‐dependent control. Furthermore, the integer electron transfer process can also be reversibly regulated via the addition of CH3CN. In addition, the temperature of 2 sharply increased and reached as high as 110 °C in 10 s upon the irradiation of near‐infrared‐II (NIR‐II) laser (1064 nm, 0.7 W cm−2), exhibiting a fast response to laser. It displays excellent photothermal stability with a photothermal (PT) conversion efficiency of 62.26 % and high‐quality PT imaging. [ABSTRACT FROM AUTHOR]

Manganese oxide-cerium oxide supported on titanate nanotubes (i.e., MnCe/TiNTs) were prepared and their catalytic activities towards NH3-SCR of NO were tested. The results indicated that the MnCe/TiNT catalyst can achieve a high NO removal efficiency above 95% within the temperature range of 150–350 °C. Even after exposure to a HCl-containing atmosphere for 2 h, the NO removal efficiency of the MnCe/TiNT catalyst maintains at approximately 90% at 150 °C. This is attributed to the large specific surface area as well as the unique hollow tubular structure of TiNTs that exposes more Ce atoms, which preferentially react with HCl and thus protect the active Mn atoms. Moreover, the abundant OH groups on TiNTs serve as Brønsted acid sites and provide H protons to expel Cl atom from the catalyst surface. The irreversible deactivation caused by HCl can be alleviated by H2O. That is because the dissociated adsorption of H2O on TiNTs forms additional OH groups and relieves HCl poisoning. [ABSTRACT FROM AUTHOR]

Coke formation poses a significant obstacle in the direct conversion of methane into valuable chemicals such as ethylene, benzene, and hydrogen via methane dehydro-aromatization (MDA). At the elevated temperatures necessary for this reaction, coke is the thermodynamically favored product, causing rapid catalyst deactivation and hence necessitating frequent catalyst regeneration. Successful industrial implementation of MDA requires the advancement of catalyst regeneration processes and a comprehensive understanding of coke formation to enhance catalyst performance. Here, we examined the types of coke generated during MDA over a Fe-ZSM-5 catalyst and their impact on deactivation. By combining reactivity studies using catalysts with carefully controlled coke populations with the characterization of the catalyst via XRD, H2-TPR, and pyridine FTIR, we find that soft coke is formed at the Brønsted acid sites, resulting in loss of selectivity, while hard coke is formed at the metal sites causing a loss of activity. While soft coke can be removed at low regeneration temperatures, the removal of hard coke requires harsh conditions which compromise catalyst stability. An investigation into the use of CO2 as an alternative, mild oxidant for catalyst regeneration, however, shows that the mild oxidation strength of CO2 requires even higher regeneration temperatures and hence irreversible loss of Brønsted acid sites. [ABSTRACT FROM AUTHOR]

The Friedel‐Crafts reaction stands as a powerful synthetic tool for C−H functionalization of aromatic feedstocks, which is conventionally realized through electrophilic alkylation and acylation. The burgeoning interests in axially chiral compounds across diverse fields have spurred extensive exploration of this classic transformation for catalytic atroposelective synthesis. Consequently, the past decade has witnessed the rapid expansion of various non‐canonical Friedel‐Crafts reactions, including electrophilic arylation, alkenylation, halogenation, sulfenylation, and amination of aryl C−H bonds, thereby delving into new chemical spaces. A range of catalytic atroposelective synthetic methods have been devised for these significant arene C−H functionalization. This review provides a comprehensive overview of the cutting‐edge catalytic synthesis of atropoisomers through non‐canonical Friedel‐Crafts reactions, categorized into three parts based on the type of bond formation on the aromatics: C(sp2)−C(sp3) bond formations, C(sp2)−C(sp2) bond formations and C(sp2)−heteroatom bond formations. The richness of electrophiles and the modulation of atroposelectivity by diverse chiral organocatalysts, particularly chiral Brønsted acids, are elucidated. We anticipate that the repertoire of asymmetric Friedel‐Crafts reaction will continue to flourish and to be demonstrated in not only scientific researches but also industrial organic synthesis. [ABSTRACT FROM AUTHOR]

The synthesis of submicrometric Y zeolites has only been achieved for a Si/Al ratio lower than 2.0 for long crystallization times. In this work, submicrometric Y zeolites in the range of 100-200 nm were synthesized with a Si/Al ratio equal to 2.4 in just 24 h. Post-synthesis methods allow tuning the porosity and the acidity of the microporous Y zeolites leading to hierarchical zeolites. Hierarchical Y zeolites were obtained by post-synthetic modification of submicrosized Y zeolites, synthesized under organic template-free conditions. The influence of the post-synthetic modification on the structure, particle size, morphology, surface area and acidic properties of the zeolites was studied. The post-synthetic modification involved either sequential desilication-dealumination (DES-DEA) or sequential dealumination-desilication (DEA-DES) of the zeolite framework involving both leaching with NaOH and steaming processes. Structurally more stable zeolites with hierarchical porosity and high crystallinity were synthesized by the sequential DES-DEA process proposed in this work. Sequential DES-DEA process allowed two relevant results in applications of these zeolites for catalysis. On one hand, it allowed a more ordered and controlled dealumination which led to retaining the number of Brønsted acid sites when the NaOH concentration was changed. Characterization of surface acidity revealed protection of the structural aluminum due to the first step of desilication before the dealumination. On the other hand, this method produced simultaneously both intraparticle and interparticle mesoporosity. With the obtained zeolites, NiMo catalysts were prepared and evaluated in the vacuum gas oil hydrocracking reaction. The catalysts based on zeolites obtained by DES-DEA were more active at lower temperatures and exhibited higher yields of middle distillates compared to those obtained with zeolites synthesized by the DEA-DES method. [ABSTRACT FROM AUTHOR]

A nitrosonium catalyzed bromination of electron‐rich arenes has been developed, using bromide salts as bromine sources, oxygen gas as a terminal oxidant and Brønsted acids (sulfuric acid, TFA or HBr). This arene bromination process is free of transition metals, proceeding in acetic acid and under mild temperatures (25–50 °C) to give brominated arenes with good to excellent yields. Our mechanistic studies indicated that this oxidative bromination of arenes reaction is catalyzed by nitrosnium ion (NO+), without the involvement of Br2 or Br+. The kinetic isotope effect of this reaction was measured using pentadeuteriophenyl phenyl ether (kH/kD=1.1). [ABSTRACT FROM AUTHOR]

ZSM-5 molecular sieves (ZSM-5-T1, ZSM-5-T2, ZSM-5-T3) were synthesized using SiO2, SiO2-8.7% C, and SiO2-23.6% C as templates from rice husk powder, respectively. Pt species were fixed within the ZSM-5 skeleton via the isovolumetric impregnation method, and the resulting catalysts were employed for the efficient oxidation of toluene (C7H8). Notably, Pt/ZSM-5-T2 exhibited the highest C7H8 catalytic oxidation activity (R175 °C = 0.733 µmol g-1 s-1, WHSV = 60 000 mL h-1 g-1) among the three variants. Furthermore, this catalyst displayed excellent water resistance when exposed to various concentrations of water vapor (2 vol%, 5 vol%, 8 vol% and 10 vol%) during the activity test. The characterization results provided insight into the exceptional catalytic performance of the Pt/ZSM-5-T2 catalyst, attributing it to its high specific surface area, appropriate hydrophilicity, abundant Lewis acid sites, and a high Pt0/(Pt0 + Pt2+) ratio. In situ DRIFTS analysis further suggested that the key step in the oxidation of C7H8 to benzyl alcohol involves C-H cleavage on Pt/ZSM-5. Simultaneously, the application of a life-cycle assessment (LCA) revealed that this strategy, involving the substitution of chemicals with biomass, led to a remarkable 41-43% reduction in carbon footprint. This environmentally friendly approach underscores the potential for repurposing rice husk powder waste. Pt/ZSM-5-T2 meets the requirements for practical applications, paving the way for sustainable resource utilization in the realm of environmental preservation. [ABSTRACT FROM AUTHOR]

Gold complexes, because of their unique carbophilic nature, have evolved as efficient catalysts for catalyzing various functionalization reactions of C–C multiple bonds. However, the realization of enantioselective transformations via gold catalysis remains challenging due to the geometrical constraints and coordination behaviors of gold complexes. In this context, merged gold/organocatalysis has emerged as one of the intriguing strategies to achieve enantioselective transformations which could not be possible by using a single catalytic system. Historically, in 2009, this field started with the merging of gold with axially chiral Brønsted acids and chiral amines to achieve enantioselective transformations. Since then, based on the unique reactivity profiles offered by each catalyst, several reports utilizing gold in conjunction with various chiral organocatalysts such as amines, Brønsted acids, N-heterocyclic carbenes, hydrogen-bonding and phosphine catalysts have been documented in the literature. This article demonstrates an up-to-date development in this field, especially focusing on the mechanistic interplay of gold catalysts with chiral organocatalysts. [ABSTRACT FROM AUTHOR]

The deep separation between In(III) and Fe(III) ions is considered as an important technological challenge in the engineering fields. The In(III) ions are closer to the soft acid in terms of Lewis acidity due to the smaller polarizability and greater deformability than the Fe(III) ions, which facilitates the possibility of separating them. Herein, the Lewis basicity of the N‐containing adsorption sites is regulated by the fluorine‐containing group to better match with the In(III) ions rather than Fe(III) ions, causing a significant discrepancy in the binding of the adsorption sites to them. Moreover, targeted programmed desorption techniques based on the potential energy differences of the adsorption sites can achieve the deep separation of In(III) and Fe(III) ions, and reach an exceptional concentration of 20.7 mmol L−1 for In(III) ions in the initial desorption solution with extremely high mass ratio (mIn/mFe = 151.7). This work provides a novel technique for in‐depth separation of In(III) and Fe(III) ions from mixed systems, and a new strategy for separating metal ions with similar or close properties. [ABSTRACT FROM AUTHOR]

As a sustainable valorization route, electrochemical glycerol oxidation reaction (GOR) involves in formation of key OH* and selective adsorption/cleavage of C−C(O) intermediates with multi‐step electron transfer, thus suffering from high potential and poor formate selectivity for most non‐noble‐metal‐based electrocatalysts. So, it remains challenging to understand the structure–property relationship as well as construct synergistic sites to realize high‐activity and high‐selectivity GOR. Herein, we successfully achieve dual‐high performance with low potentials and superior formate selectivity for GOR by forming synergistic Lewis and Brønsted acid sites in Ni‐alloyed Co‐based spinel. The optimized NiCo oxide solid‐acid electrocatalyst exhibits low reaction potential (1.219 V@10 mA/cm2) and high formate selectivity (94.0 %) toward GOR. In situ electrochemical impedance spectroscopy and pH‐dependence measurements show that the Lewis acid centers could accelerate OH* production, while the Brønsted acid centers are proved to facilitate high‐selectivity formation of formate. Theoretical calculations reveal that NiCo alloyed oxide shows appropriate d‐band center, thus balancing adsorption/desorption of C−O intermediates. This study provides new insights into rationally designing solid‐acid electrocatalysts for biomass electro‐upcycling. [ABSTRACT FROM AUTHOR]

In this work, the addition of 5%SiO2 to 7.5%WO3-ZrO2 catalyst increased the content of tetragonal ZrO2 and BET, which could promote the formation of W–O–Zr(Si) bonds between WOx species and 5%SiO2-ZrO2 material, thus reducing the degree of aggregation of WOx species. The oligomerized WOx species on the 7.5%WO3-5%SiO2-ZrO2 catalyst could not only remain stable, but also provided stable Lewis acid for the activation of hydrogen peroxide and maleic anhydride for epoxidation. In addition, the Si–O–Zr bond on SiO2-modified 7.5%WO3-ZrO2 catalyst could provide an additional Brønsted acid site for activating the hydrolysis of epoxysuccinic acid to DL-tartaric acid. Therefore, the DL-tartaric acid yield of SiO2-modified 7.5%WO3-ZrO2 catalyst was higher than that of 7.5%WO3-ZrO2 catalyst, and also higher than that of Na2WO4 catalyst. The SiO2-modified 7.5%WO3-ZrO2 catalyst rich in stable Lewis and Brønsted acid not only had good cyclic stability but also had good catalytic activity under mild condition. [ABSTRACT FROM AUTHOR]

In the past few decades, N-heterocyclic carbenes (NHCs) have opened the new field of organocatalysis in synthetic organic chemistry. This review highlights the dramatic progress in the field of NHC-catalyzed C–O bond formation based on the activation of aldehyde C(sp2)–H bonds. The oxidative and redox transformations for the synthesis of various molecules with structural diversity and complexity are summarized. Furthermore, new methods and strategies for NHC catalysis are emerging continuously; thus, cooperative catalysis with Brønsted acid, hydrogen-bonding catalyst, transition-metal catalyst, and photocatalyst are also described. [ABSTRACT FROM AUTHOR]

Furan heterocyclic compounds derived from renewable sources are popular versatile candidates for the production of multifunctional macromolecular materials. These compounds are also used as hydrophobilization monomers for reversible polyadducts or as versatile building blocks in Diels‐Alder reactions. In the present study, an efficient approach to chemoselective acylation of furfurylamine with a series of non‐preactivated monocarboxylic or dicarboxylic long‐chain fatty acids and some of their functionalized derivatives has been achieved via catalytic direct amidation in reversed micellar medium. A convenient and environmentally friendly method has been developed for furfurylamides via a dehydrative coupling reaction. For this purpose, a new cationic Brønsted‐type sulfonic acid catalyst containing a hexadecyl alkyl chain was synthesized and fully characterized. The present catalytic reaction produced the respective N‐furfurylamides materials in good to excellent yields. This study also confirms that the direct amidation of carboxylic acids with selected amine compounds can be successfully catalyzed by Brønsted acids. Its simplicity and high atom economy are the main advantages of this method. [ABSTRACT FROM AUTHOR]

Ca-type todorokite catalysts were designed and prepared by a simple redox method and applied to the selective reduction of NO x by NH 3 (NH 3 -SCR) for the first time. Compared with the Na-type manjiroite prepared by the same method, the todorokite catalysts with different Mn/Ca ratios showed greatly improved catalytic activity for NO x reduction. Among them, Mn8Ca4 catalyst exhibited the best NH 3 -SCR performance, achieving 90% NO x conversion within temperature range of 70–275°C and having a high sulphur resistance. Compared to the Na-type manjiroite sample, Ca-type todorokite catalysts possessed an increased size of tunnel, resulting in a larger specific surface area. As increased the amounts of Ca doping, the Na content in Ca-type todorokite catalysts significantly decreased, providing larger amounts of Brønsted acid sites for NH 3 adsorption to produce NH 4 +. The NH 4 + species were highly active for reaction with NO + O 2 , playing a determining role in NH 3 -SCR process at low temperatures. Meanwhile, larger amounts of surface adsorbed oxygen contained over the Ca-doping samples than that over Na-type manjiroite, promoting the oxidation of NO and fast SCR processes. Over the Ca-type todorokite catalysts, furthermore, nitrates produced during the flow of NO + O 2 , were more active for reaction with NH 3 than that over Na-type manjiroite, benefiting the occurrence of NH 3 -SCR process. This study provides novel insights into the design of NH 3 -SCR catalysts with high performance. [Display omitted] [ABSTRACT FROM AUTHOR]

Development of an environmentally friendly catalyst system is a highly attractive strategy for organic synthesis. In this work, a H-form mesoporous Beta (H-MBeta) zeolite with an irregular spherical particle shape was synthesized and was found to realize the direct amidation of styrene and nitriles for the synthesis of N-alkylated amides in the aqueous phase. This strong acidic H-MBeta catalyst exhibited superior activity and product selectivity compared with H-MBeta-0.3 and H-MBeta-1.0 zeolites obtained from the acid dealumination method. This was attributed to the presence of abundant strong Brønsted acid sites in the H-MBeta zeolite, which can induce the adsorption and activation of styrene through the C＝C bond interacting with protonic hydrogen, benefiting the formation of key intermediate carbocation. [ABSTRACT FROM AUTHOR]

Four different isomeric azadibenzo[a,e]pyrenes (benzo[4,10]anthra[9,1‐gh]isoquinolines and benzo[4,10]anthra[1,9‐fg]isoquinolines) were prepared by combination of Pd‐catalyzed Sonogashira and Suzuki cross‐coupling, Brønsted acid mediated cycloisomerization and Pd‐catalysed CH‐activation reactions. The optical properties have been studied by steady‐state absorption and emission spectroscopy in different solvents and during acid titration. Trifluoroacetic acid protonation strongly affects absorption and emission properties, with variations depending on the position of the nitrogen atom of the specific compound. Electrochemical analysis showed distinct oxidation and reduction potentials. DFT calculations provided further insights into electronic properties. [ABSTRACT FROM AUTHOR]

The influence of adding Cr(III) compounds into Zn−BEA zeolite samples (with silicate modulus Si/Al=17, 100, and 1000) on the redox and acid–base characteristics of Cr/Zn−BEA zeolites were studied, and their catalytic properties in propane dehydrogenation with CO2 to propylene. It was established (based on the XRD, low–temperature (77 K) ad/desorption of N2, TPR−H2, TPD−MSC−NH3(CO2), C3H8(C3H6), FTIR−Py data) that the acid–base characteristics of the surface of bifunctional Cr/Zn−BEA catalysts, namely the amount, strength, and nature (Lewis and Brønsted sites), determine their activity/selectivity, and operation stability in the process of CO2−PDH. This indicates that over Cr/Zn−BEA catalysts, the process runs along the route of direct propane dehydrogenation combined with the reverse water gas shift reaction. [ABSTRACT FROM AUTHOR]

The interconversion of monoterpenes is facilitated by a complex network of carbocation rearrangement pathways. Controlling these isomerization pathways is challenging when using common Brønsted and Lewis acid catalysts, which often produce product mixtures that are difficult to separate. In contrast, natural monoterpene cyclases exhibit high control over the carbocation rearrangement reactions but are reliant on phosphorylated substrates. In this study, we present engineered squalene‐hopene cyclases from Alicyclobacillus acidocaldarius (AacSHC) that catalyze the challenging isomerization of monoterpenes with unprecedented precision. Starting from a promiscuous isomerization of (+)‐β‐pinene, we first demonstrate noticeable shifts in the product distribution solely by introducing single point mutations. Furthermore, we showcase the tuneable cation steering by enhancing (+)‐borneol selectivity from 1 % to >90 % (>99 % de) aided by iterative saturation mutagenesis. Our combined experimental and computational data suggest that the reorganization of key aromatic residues leads to the restructuring of the water network that facilitates the selective termination of the secondary isobornyl cation. This work expands our mechanistic understanding of carbocation rearrangements and sets the stage for target‐oriented skeletal reorganization of broadly abundant terpenes. [ABSTRACT FROM AUTHOR]

The interconversion of monoterpenes is facilitated by a complex network of carbocation rearrangement pathways. Controlling these isomerization pathways is challenging when using common Brønsted and Lewis acid catalysts, which often produce product mixtures that are difficult to separate. In contrast, natural monoterpene cyclases exhibit high control over the carbocation rearrangement reactions but are reliant on phosphorylated substrates. In this study, we present engineered squalene‐hopene cyclases from Alicyclobacillus acidocaldarius (AacSHC) that catalyze the challenging isomerization of monoterpenes with unprecedented precision. Starting from a promiscuous isomerization of (+)‐β‐pinene, we first demonstrate noticeable shifts in the product distribution solely by introducing single point mutations. Furthermore, we showcase the tuneable cation steering by enhancing (+)‐borneol selectivity from 1 % to >90 % (>99 % de) aided by iterative saturation mutagenesis. Our combined experimental and computational data suggest that the reorganization of key aromatic residues leads to the restructuring of the water network that facilitates the selective termination of the secondary isobornyl cation. This work expands our mechanistic understanding of carbocation rearrangements and sets the stage for target‐oriented skeletal reorganization of broadly abundant terpenes. [ABSTRACT FROM AUTHOR]

Brønsted acid mediated [3+2] cycloaddition of coumarin‐based enamines with 3‐ylidene oxindoles generated in situ from 3‐hydroxy‐3‐aroylmethyl oxindoles enabled the synthesis of polyheterocyclic compounds with a pyrrolocoumarin core structure in a highly regioselective manner. The synthetic procedure is highly efficient and metal‐free, and no chromatographic purification of the products is required. The chromenopyrrole derivatives bearing an oxindole moiety formed as rapidly interconverting rotamers. [ABSTRACT FROM AUTHOR]

5‐hydroxymethylfurfural (5‐HMF) has been considered as an important biomass‐based platform chemical for its wide applications. Currently, the production of 5‐HMF from the catalytic dehydration of glucose is preferred, in which the Brønsted and Lewis acids in catalysts play an important role. Here, it was found that MIL‐53(Al) modified with tin was an active, selective, and reusable catalyst for the transformation of glucose to 5‐HMF in dimethyl sulfoxide (DMSO) solvent. Around 42.3% yield of 5‐HMF with 93% glucose conversion was achieved, when the prepared metal‐organic frameworks (MOFs) was used as the catalyst, showing superior catalytic performance compared with most of other MOFs. Moreover, the catalyst possessed inert catalytic properties in water with almost no any influence on the conversion of glucose, suggesting a compelling opportunity to act as a support material. [ABSTRACT FROM AUTHOR]

2,5‐Bis(propoxymethyl)furan (BPMF) is a potential biofuel candidate but it is difficult to synthesize it selectively. The Lewis acid sites and Brønsted acid sites of the catalyst play a key role BPMF's selectivity. In the present work, the effect of tunable acidic properties such as the Lewis and Brønsted acidity of Sn‐Hβ and Sn‐dAlβ (Sn in dealuminated Hβ) catalysts on the selectivity of BPMF was studied by carrying out one‐pot reductive etherification of 5‐hydroxymethylfurfural (5‐HMF) using 2‐propanol as a hydrogen donor. The catalysts that were prepared underwent analysis using techniques such as temperature‐programmed desorption of ammonia (NH3‐TPD), powder X‐ray diffraction, transmission electron microscopy, pyridine‐IR spectroscopy, Brunauer–Emmett–Teller (BET) surface area measurement, and Fourier transform infrared spectroscopy. Under the optimized reaction conditions, which included a temperature of 150 °C, a catalyst loading of 0.25 g, a reaction time of 4 h, and a concentration of 1 g of 5‐HMF, impressive results were obtained: 93.57% conversion of 5‐HMF and 98.54% selectivity towards BPMF. It was observed that the catalysts remained active for up to five cycles and slight/moderate change was observed in the conversion of 5‐HMF, while the selectivity of BPMF remained intact. [ABSTRACT FROM AUTHOR]

We report the helicoselective and convergent construction of indolohelicenoids with excellent efficiency and stereocontrol. This reaction proceeds through a chiral‐phosphoric‐acid‐catalyzed enantioselective cycloaddition and eliminative aromatization sequence, which can be finely controlled by adjusting the reaction temperature. Mechanistic studies reveal that the chiral phosphoric acid cooperatively serves as both a bifunctional and Brønsted acid catalyst, enabling one‐pot central‐to‐helical chirality conversion. Additionally, the optical properties of the synthesized indolohelicenoids were characterized to explore their potential applications in organic photoelectric materials. [ABSTRACT FROM AUTHOR]

We report the helicoselective and convergent construction of indolohelicenoids with excellent efficiency and stereocontrol. This reaction proceeds through a chiral‐phosphoric‐acid‐catalyzed enantioselective cycloaddition and eliminative aromatization sequence, which can be finely controlled by adjusting the reaction temperature. Mechanistic studies reveal that the chiral phosphoric acid cooperatively serves as both a bifunctional and Brønsted acid catalyst, enabling one‐pot central‐to‐helical chirality conversion. Additionally, the optical properties of the synthesized indolohelicenoids were characterized to explore their potential applications in organic photoelectric materials. [ABSTRACT FROM AUTHOR]