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Microflow catalysis is a cutting-edge approach to advancing chemical synthesis and manufacturing, but the challenge lies in developing efficient and stable multiphase catalysts. Here we showcase incorporating amine-containing metal-organic cages into automated microfluidic reactors through covalent bonds, enabling highly continuous flow catalysis. Two Fe4L4 tetrahedral cages bearing four uncoordinated amines were designed and synthesized. Post-synthetic modifications of the amine groups with 3-isocyanatopropyltriethoxysilane, introducing silane chains immobilized on the inner walls of the microfluidic reactor. The immobilized cages prove highly efficient for the reaction of anthranilamide with aldehydes, showing superior reactivity and recyclability relative to free cages. This superiority arises from the large cavity, facilitating substrate accommodation and conversion, a high mass transfer rate and stable covalent bonds between cage and microreactor. This study exemplifies the synergy of cages with microreactor technology, highlighting the benefits of heterogenous cages and the potential for future automated synthesis processes Microflow catalysis represents a cutting-edge method for advancing chemical synthesis and manufacturing, though developing efficient and stable multiphase catalysts remains challenging. Here the authors demonstrate the incorporation of amine-containing metal-organic cages into automated microfluidic reactors through covalent bonds, facilitating highly continuous flow catalysis. [ABSTRACT FROM AUTHOR]

During the past decades, N‐heterocyclic carbene (NHC)‐catalyzed reactions have emerged as a versatile tool in synthetic chemistry. In particular, NHC‐catalyzed cross‐coupling reaction has been significantly developed in many respects, including new reaction development and mechanistic investigation. This concept article presents recent advances towards direct cross‐coupling reactions of aldehydes with alkyl halides enabled by NHC organocatalysis. [ABSTRACT FROM AUTHOR]

Supramolecular assembly frameworks (SAFs) represent a new category of porous materials, utilizing non‐covalent interactions, setting them apart from metal–organic frameworks (MOFs) and covalent organic frameworks (COFs). This category includes but is not restricted to hydrogen‐bonded organic frameworks and supramolecular organic frameworks. SAFs stand out for their outstanding porosity, crystallinity, and stability, alongside unique dissolution‐recrystallization dynamics that enable significant structural and functional modifications. Crucially, their non‐covalent assembly strategies allow for a balanced manipulation of porosity, symmetry, crystallinity, and dimensions, facilitating the creation of advanced crystalline porous materials unattainable through conventional covalent or coordination bond synthesis. Despite their considerable promise in overcoming several limitations inherent to MOFs and COFs, particularly in terms of solution‐processability, SAFs have received relatively little attention in recent literature. This Minireview aims to shed light on standout SAFs, exploring their design principles, synthesis strategies, and characterization methods. It emphasizes their distinctive features and the broad spectrum of potential applications across various domains, aiming to catalyze further development and practical application within the scientific community. [ABSTRACT FROM AUTHOR]

The whole-cell catalysis strategy of alpha-ketoglutaric acid (α-KG) production from L-glutamic acid (L-Glu) using recombinant Escherichia coli, in which L-glutamate oxidase (LGox) was over-expressed, has replaced the traditional chemical synthesis strategy. However, large amounts of toxic by-product, H2O2, should be eliminated through co-expressing catalase (Cat), thus severely increasing burden in cells. To efficiently and economically produce α-KG, here, the genes SpLGox (from Streptomyces platensis NTU3304) and SlCat (from Streptomyces lividans TK24) were inserted into the low-dosage-IPTG (Isopropyl β-D-Thiogalactoside) inducible expression system, constructed in our previous work, in E. coli, respectively. Besides, a double-strain catalysis system was established and optimized to produce α-KG, and the productivity of α-KG was increased 97% compared with that through single strain catalysis. Finally, a double-strain cultivation strategy was designed and employed to simplify the scale-up fermentation. Using the optimized whole-cell biocatalyst conditions (pH 7.0, 35 °C), majority of the L-glutamic acid was transformed into α-KG and the titer reached 95.4 g/L after 6 h with the highest productivity at present. Therefore, this strategy may efficiently and cost-effectively produce α-KG, enhancing its potential for industrial applications. Key points: • SpLGox and SlCat were over-expressed to catalyze L-Glu to α-KG and eliminate by-product H2O2, respectively. • Double-strain cultivation and catalysis system can efficiently and cost-effectively produce α-KG from L-Glu. [ABSTRACT FROM AUTHOR]

Nitrogen‐doped carbon is considered one of the most promising oxygen reduction catalysts due to its low cost and high activity, however, it still falls short of Pt/C. In this study, we report a strategy for the preparation of highly reactive N‐doped hierarchical porous carbon by primary pyrolysis using zinc acetate as a stand‐alone zinc source and amino‐rich reactants as carbon and nitrogen sources to introduce Zn‐Nx structures into mesoporous structures generated by the hard template method using the strong coordination of zinc and amino groups. Benefited from the simultaneous optimization of the hierarchical porous structure and nitrogen‐doping, the half‐wave potential of Zn(OAc)2–DCD/HPC is as high as 0.909 V vs. RHE, much better than that of commercial Pt/C catalysts (0.872 V vs. RHE). In addition, zinc‐air batteries assembled with Zn(OAc)2–DCD/HPC (Pmax=198 mW cm−2) as the cathode exhibit higher peak power density compared to Pt/C (Pmax=168 mW cm−2). This strategy might open up new opportunities for designing and developing highly active metal‐free catalysts. [ABSTRACT FROM AUTHOR]

The catalytic bis‐allylation of alkynes is an important but challenging protocol to construct all‐carbon tetra‐substituted alkenes. Particularly, the catalytic unsymmetrical bis‐allylation of alkynes remains as an underexplored task to date. We herein report an unprecedented unsymmetrical bis‐allylation by simultaneously utilizing electrophilic trifluoromethyl alkene and nucleophilic allylboronate as the allylic reagents. With the aid of robust Ni0/NHC catalysis, valuable skipped trienes can be obtained in high regio‐ and stereo‐selectivities under mild conditions. Mechanistic studies indicate that the reaction may proceed through a β‐fluorine elimination of a nickelacycle followed by a transmetalation step with allylboronate. The present method exhibits a good tolerance of various functional groups. Besides, the skipped triene products can undergo an array of elaborate transformations, which highlights the potential applications of this strategy. [ABSTRACT FROM AUTHOR]

Oxidative N‐heterocyclic carbene (NHC) organocatalysis, typically leading to the formation of acyl azolium reactive intermediates, constitutes one of the most important activation strategies for the NHC‐catalyzed chemical transformations. Here, we report an unprecedented oxidative radical NHC catalysis by using peroxyester as the external single‐electron oxidant to realize divergent difunctionalization of olefins. The key to success of this chemistry is the catalytic generation of oxygen radicals that could trigger an intermolecular hydrogen atom transfer to activate the inert C−H bonds, thereby enabling the productive radical relay process. With this protocol, commonly used general chemicals could serve as radical precursors to allow efficient synthesis of value‐added products in a straightforward and cost‐effective manner. Preliminary mechanistic investigations, including control experiments and DFT calculations, shed light on the NHC organocatalytic radical reaction mechanism. [ABSTRACT FROM AUTHOR]

The asymmetric synthesis of chiral amino acids by leucine dehydrogenases has great potential for industrialization; however, the inhibitory effect of high‐concentration substrates limits its large‐scale application. Herein, using structure‐guided genome mining based on sequence‐structure prediction of substrate tolerance and specificity, a novel leucine dehydrogenase (LaLeuDH) from Labrenzia aggregate was identified and characterized, which exhibited the highest substrate tolerance and excellent activity to trimethyl pyruvate, even at 1.5 M concentration. Moreover, based on coenzyme binding structural information and sequence alignment, directed evolution of LaLeuDH was performed to increase affinity for NADH. The obtained variant D153 N/H191 N resulted in 25‐fold improved affinity for NADH, with 50‐fold enhanced catalytic efficiency (kcat/Km) of 40464.6 mM−1 s−1. Finally, through a combination of the above two strategies, as high as 1.5 M substrate could be completely converted in 18 h without coenzyme addition, demonstrating that this engineered enzyme has promising prospects for industrialization. [ABSTRACT FROM AUTHOR]

Dehydrogenative coupling (DC) and borrowing hydrogen(ation) (BH) reactions are crucial in modern organic synthesis, offering efficient and sustainable ways to create valuable compounds. However, they often face a significant challenge: the alkoxide trap. This Concept explores the alkoxide trap in DC and BH reactions, starting with the basic mechanisms and the role of alkoxide intermediates. It then examines how the alkoxide trap leads to catalyst deactivation and reduced selectivity, influenced by thermodynamic and kinetic factors. To address this, we review recent advances in catalyst design, ligand engineering, and optimized reaction conditions, along with the use of in‐situ spectroscopy and computational modelling, to better understand the underlying processes and guide rational catalyst development. Furthermore, this Concept highlights the broad applicability of DC, and BH reactions across various substrates, underscoring the urgency of addressing the alkoxide trap issue to unlock their full synthetic potential. [ABSTRACT FROM AUTHOR]

Developing an efficient signal amplification strategy is very important to improve the sensitivity of bioanalysis. In this paper, a liposome-assisted enzyme catalysis signal amplification strategy was developed for electrochemiluminescence (ECL) immunoassay of prostate specific antigen (PSA) in a split-type mode. The sandwich immunoreaction occurred in a 96-well plate, and glucose oxidase (GOx) encapsulated and antibody-modified liposomes were used as labels. The ECL detection was carried out using a rGO-Au NP modified glassy carbon electrode (GCE). The large amount of generated H2O2, i.e. the coreactant of the luminol system, and the excellent catalytic behavior of rGO-Au NPs greatly boosted the ECL signal, resulting in the signal amplification. The developed ECL immunosensor for detecting PSA achieved a wider linear range from 1.0 × 10−13 to 1.0 × 10−8 g mL−1 and a detection limit of 1.7 × 10−14 g mL−1. The application of the proposed strategy was demonstrated by analyzing PSA in human serum samples with recoveries from 89.0% to 113.0%, and relative standard deviations (RSDs) were less than 6.6%. This work provides a new horizon to expand the application of liposomes for ECL bioanalysis. [ABSTRACT FROM AUTHOR]

The article titled "Retraction Note: A New Porous Metal–Organic Framework Constructed from 2, 5-Thiophenedicarboxylate and Melamine Ligands: Catalysis Dye Degradation and Anti-tumor Activity in Myocardioma" has been retracted by the Editor-in-Chief and the Publisher of the Journal of Cluster Science. The retraction was prompted by evidence of systematic manipulation of the publication process, including issues with citations, phrasing, figures, and ethics approval statements. The authors have not responded to correspondence regarding the retraction. Springer Nature, the publisher, remains neutral in regards to jurisdictional claims and institutional affiliations. [Extracted from the article]

3D covalent organic frameworks (COFs) with well‐defined porous channels are shown to be capable of inducing chiral molecular catalysts from non‐enantioselective to highly enantioselective in catalyzing organic transformations. By condensations of a tetrahedral tetraamine and two linear dialdehydes derived from enantiopure 1,1′‐binaphthol (BINOL), two chiral 3D COFs with a 9‐fold or 11‐fold interpenetrated diamondoid framework are prepared. Enhanced Brønsted acidity was observed for the chiral BINOL units that are uniformly distributed within the tubular channels compared to the non‐immobilized acids. This facilitates the Brønsted acid catalysis of cyclocondensation of aldehydes and anthranilamides to produce 2,3‐dihydroquinazolinones. DFT calculations show the COF catalyst provides preferential secondary interactions between the substrate and framework to induce enantioselectivities that are not achievable in homogeneous systems. [ABSTRACT FROM AUTHOR]

Herein, the first allylsilane reagent‐controlled divergent asymmetric Hosomi–Sakurai conjugate allylation and hetero‐Diels–Alder (HDA) with 2‐naphthoquinone‐1‐methide (2‐Nap‐Q‐1‐M) under the catalysis of ScIII/Feng ligand complex is reported. With these methods, a variety of uniquely substituted chiral allyl‐functionalized diaryl compounds and naphthopyran products were obtained in a straightforward and highly stereoselective (up to 96.5:3.5 e.r.) manner under mild conditions. Moreover, it is demonstrated that 2‐Nap‐Q‐1‐M can serve as an efficient diene for a side asymmetric Diels–Alder (D‐A) reaction. This principle can provide a straightforward access to hydrophenalene in an optically active form, which represents a structural core of various natural products and bioactive molecules. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) are constructed using reticular chemistry with the building blocks being connected via covalent bonds and have emerged as a new series of porous materials for multitudinous applications. Most COFs reported to date are achiral, and only a small fraction of COFs with chiral nature are reported. This review covers the recent advances in the field of chiral COFs (CCOFs), including their design principles and synthetic strategies, structural studies, and potential applications in asymmetric catalysis, enantioselective separation, and chiral recognition. Finally, we illustrate the remaining challenges and future opportunities in this field. [ABSTRACT FROM AUTHOR]

A type of optically pure secondary‐amino aromatic Tf‐amide organocatalysts can be easily prepared from commercially available L‐hydroxyproline. The chemical behavior of these organocatalysts was investigated by the application to asymmetric aldol reactions. Among these, catalyst 2 a efficiently catalyzed direct asymmetric aldol reactions of cycloalkanones and substituted benzaldehydes, which afforded the corresponding aldol adducts in good yield with good to excellent anti‐diastereo and enantioselectivity. [ABSTRACT FROM AUTHOR]

A new three-dimensional transition Co(II)–organic framework {[Co2L2MA]·(DMA)(MeOH)}n (MA = melamine, H2L = 2,5-thiophenedicarboxylic acid) bearing the rigid S-containing organic ligand 2,5-thiophenedicarboxylic acid and the N-rich organic linker melamine has been synthesized and structurally characterized. The presence of abundant micropores in the resulting activated 1a has been confirmed via the N2 sorption experiments at 77 K, which reflects a BET surface area of 925 m2/g and a pore size distribution of 7.4 Å. Furthermore, the catalytic activities of complex 1 for the degradation of methyl orange in a Fenton-like process have also investigated, which reveals that complex 1 could behave as effective as heterogeneous catalyst to activate persulfate anions and to degrade methyl orange. To evaluate the inhibitory effect of compound 1 on H9C2 myocardioma cells, the viability of cells after compound treatment was detected by CCK-8 assay, and the proliferation of cells were observed by colony formation assay. Next, the detail mechanism of compound 1 was further explored, the western blot was performed to determine the relative expression of apoptotic protein Blc-2 and Bax. [ABSTRACT FROM AUTHOR]

Chiral phosphoric acids are incorporated into indium‐based metal–organic frameworks (In‐MOFs) by sterically preventing them from coordination. This concept leads to the synthesis of three chiral porous 3D In‐MOFs with different network topologies constructed from three enantiopure 1,1′‐biphenol‐phosphoric acid derived tetracarboxylate linkers. More importantly, all the uncoordinated phosphoric acid groups are periodically aligned within the channels and display significantly enhanced acidity compared to the non‐immobilized acids. This facilitates the Brønsted acid catalysis of asymmetric condensation/amine addition and imine reduction. The enantioselectivities can be tuned (up to >99 % ee) by varying the substituents to achieve a nearly linear correlation with the concentrations of steric bulky groups in the MOFs. DFT calculations suggest that the framework provides a chiral confined microenvironment that dictates both selectivity and reactivity of chiral MOFs. [ABSTRACT FROM AUTHOR]

Inspired by the high efficiency and specificity of enzymes in living systems, the development of artificial catalysts intrinsic to the key features of enzyme has emerged as an active field. Recent advances in supramolecular chemistry have shown that supramolecular coordination cages, built from non‐covalent coordination bonds, offer a diverse platform for enzyme mimics. Their inherent confined cavity, analogous to the binding pocket of an enzyme, and the facile tunability of building blocks are essential for substrate recognition, transition‐state stabilization, and product release. In particular, the combination of chirality with supramolecular coordination cages will undoubtedly create an asymmetric microenvironment for promoting enantioselective transformation, thus providing not only a way to make synthetically useful asymmetric catalysts, but also a model to gain a better understanding for the fundamental principles of enzymatic catalysis in a chiral environment. The focus here is on recent progress of supramolecular coordination cages for asymmetric catalysis, and based on how supramolecular coordination cages function as reaction vessels, three approaches have been demonstrated. The aim of this review is to offer researchers general guidance and insight into the rational design of sophisticated cage containers for asymmetric catalysis. Trapped in confined spaces: Supramolecular coordination cages feature an inherent confined cavity analogous to the binding pocket of enzymes. Coupled with chirality, supramolecular coordination cages provide a way to prepare synthetically useful asymmetric catalysts. Based on how supramolecular coordination cages function as reaction vessels, several approaches are demonstrated. [ABSTRACT FROM AUTHOR]

Abstract: A strategy for the synthesis of quinazolinones via Ru‐catalyzed redox isomerization/acceptorless dehydrogenation was proposed and accomplished. In the presence of a commercially available [(p‐cymene)Cl2]2, a range of desirable products were obtained with o‐aminobenzamides and allylic alcohols as starting materials in moderate to high yields. This strategy is attractive due to high atom efficiency, and minimal consumption of chemicals and energy. [ABSTRACT FROM AUTHOR]

Abstract: “Unprotected” Pt nanocrystals were modified with triphenylphosphine (PPh3), octadecylamine (ODA), poly(vinylpyrrolidone) (PVP), poly(vinyl alcohol) (PVA), and dodecanethiol (DT) to investigate the effect of protective agents on the intrinsic catalytic property of Pt nanocrystals. By evaluating the catalytic performance of these model catalysts for the hydrogenation of para‐chloronitrobenzene (p‐CNB), it was found that direct or indirect interaction between nanocrystals and protective agents imposed a great impact on the catalytic performance of the nanocrystals. Protective agents with different electron‐donating ability (PPh3, ODA, PVP, and PVA) directly altered surface electronic state of Pt nanocrystals to bring the surface Pt atoms into an electron‐rich state, which would exert influence on the hydrogenation course by changing the adsorption and the reactivity of reactant, intermediates, and products. In contrast, DT exerted an indirect influence on the Pt nanocrystals. The coordinated Pt atoms were oxidized by DT to generate cationic Pt species on the surface of nanocrystals, and the cationic species would simultaneously improve the hydrogenation rate and selectivity to para‐chloroaniline by polarizing the N=O bond in the −NO2 group of p‐CNB and altering the electronic state of Pt nanocrystals, respectively. This work provided further insights into nanocatalysis, which is helpful for further design and application of highly efficient nanocrystal catalysts. [ABSTRACT FROM AUTHOR]

The purpose of present study was to investigate the interfacial behaviors of the peroxidase-catalyzed intermolecular conjugates of corn fiber gum (CFG) and bovine serum albumin (BSA) (gum and protein weight ratio of 4:1). CFG-BSA conjugate stabilized emulsion remained stable with low flocculation and coalescence degree during storage in comparison to single BSA or CFG emulsion, attributing to its higher amount of adsorbed protein and polysaccharide. As shown by SDS-sulfate polyacrylamide gel electrophoresis, the adsorbed protein at the surface of oil droplets stabilized by CFG-BSA conjugate was partly crosslinked with CFG, forming an entangled emulsion network with increased apparent viscosity. Adsorbed CFG-BSA conjugates distributed loosely around the droplet interfaces as revealed by images of confocal laser scanning microscopy. Their interfacial layer thickness was estimated to be 85.1 nm using a monodisperse polystyrene latex particle model, which was not only larger than the adsorbed layer thickness of single CFG (71 nm) or BSA (6.9 nm) but also their combined layer thickness. To our knowledge, it is the first time that the interfacial properties of enzymatically-crosslinked polysaccharide and protein have been studied. [ABSTRACT FROM AUTHOR]