Owing to its promiscuous substrate specificity and high catalytic efficiency, the bacterial α2,6-sialyltransferase from Photobacterium damselae (Pd2,6ST) has been widely used for the synthesis of various α2,6-linked sialosides. However, Pd2,6ST is not a suitable enzyme for the regioselective α2,6-sialylation of complex acceptor substrates containing multiple galactose (Gal) and/or N-acetylgalactosamine (GalNAc) residues due to its promiscuous substrate specificity. In this study, a novel enzymatic substrate engineering strategy was developed to overcome this limitation by employing enzymatically introduced α2,6-linked ketodeoxynonulosonic acid (Kdn) as temporary “protecting group” at the unwanted sialylation sites. The Kdn “protecting group” can be selectively removed by a ketodeoxynonulosonic acid hydrolase from Aspergillus fumigatus (AfKdnase) at appropriate stage without affecting coexisting sialic acid residues, such as N-acetylneuraminic acid (Neu5Ac) or N-glycolylneuraminic acid (Neu5Gc). This strategy provides a general and practical approach for the synthesis of complex sialosides, including sialylated poly-LacNAc glycans, disialylated ganglioside glycan epitopes, and branched human milk oligosaccharides.

In recent years, the study of the photochromic behavior of phenothiazine derivatives has not only enriched the variety of color-changing materials but also provided new donor molecules for the construction of Förster Resonance Energy Transfer (FRET). This advancement broadens the application potential of photochromic materials and offers fresh perspective for FRET research. Herein, pillar[5]arene-linked biphenothiazine derivative (DPP5) was synthesized, while p-dibenzyl-linked biphenothiazine derivative (DPDB) and butyl-linked biphenothiazine derivative (DPB) were designed for comparative study. The photochromic behavior was demonstrated by UV-vis spectra, electron paramagnetic resonance (EPR) and chemical oxidation method, showing the transformation of DPP5 molecule into the radical cation DPP5^•+ and subsequently into the dication DPP5²⁺. Furthermore, a FRET system was constructed using dication species DPP5²⁺ as the energy donor and Nile red (NiR) as the energy acceptor. The introduction of guest molecules, 1,6-dibromohexane (1,6-DBH) and 1,10-dibromodecane (1,10-DBD), into the above FRET system enhanced the energy transfer efficiency by increasing the aggregation degree of FRET system by utilizing the cavity of pillar[5]arene through host-guest interaction. The application of the photochromic behavior of phenothiazine derivatives into FRET system, along with the strategy of using guest molecule to enhance FRET properties, will contribute to the development of novel photochromic materials.

This study explores the use of supramolecular RAFT polymerization for the efficient synthesis of pseudorotaxanes and functional nanosheets through the host-guest interaction between β-cyclodextrin (β-CD) and the chain transfer agent (CTA) S,S’-bis(α,α’-dimethylacetic acid) trithiocarbonate (BDAAT). The formation of the β-CD@BDAAT complex significantly improves the water solubility of the CTA, thereby increasing the polymerization rate for N,N-dimethylacrylamide (DMA) and generating well-defined pseudorotaxane structure. In the process of aqueous polymerization-induced self-assembly (PISA), this supramolecular approach enables the rapid fabrication of functional nanosheets, reducing the required time from one week to just 5 h. The non-covalent support provided by β-CD is crucial for stabilizing the layered nanosheet assembly, while host-guest competition experiments also demonstrate the tunability of the morphology of non-covalently assembled structures. This study highlights the versatility of supramolecular RAFT polymerization, offering a promising strategy for the rapid and efficient production of complex nanostructures in aqueous media.

Photocatalytic synthesis of hydrogen peroxide (H₂O₂) from air and water presents a sustainable and efficient alternative to the traditional anthraquinone method. Therefore, the design and synthesis of efficient photocatalysts for H₂O₂ production are important. In this work, we apply a nitrogen-site engineering strategy to achieve high-performance photocatalysts by synthesizing three imine- linked oligo(phenylenevinylene)-based covalent organic frameworks (OPV-COFs) doped with different numbers of nitrogen atoms (denoted as COF-920-nN, n = 0, 1, 3). Comprehensive characterization confirmed the high crystallinity and porosity of the COFs, critical for efficient photocatalysis. Each OPV-COF exhibited the ability to rapidly synthesize H₂O₂ using air and water, with COF-920-1N achieving the highest rate of 4288 μmol·g^–1·h^–1 under visible light, higher than those of most of other reported COFs. Mechanism studies demonstrated that the introduction of pyridine nitrogen atoms at the junction changes the electronic structure and electron transfer path within the COFs, enhancing the photogenerated electron mobility and reducing the rate of electron-hole recombination. This study not only pioneers the class of OPV-COFs for photocatalytic synthesis of H₂O₂, but also sets a foundational strategy for the rational design of COFs in photocatalytic applications.

We developed single-component nonchemically-amplified resists (n-CARs) based on calixarene derivatives for high-resolution nanopatterning with electron beam lithography (EBL) and extreme ultraviolet lithography (EUVL). The calixarene derivatives decorated with 2 and 4 photosensitive sulfonium groups (C2S and C4S, respectively) were synthesized and characterized. Both derivatives exhibit excellent thermal stability and film-forming properties, making them suitable as resist materials. A comparative EBL study reveals that C2S resist exhibits superior lithographic performance. The presence of hydrogen bonds between C2S molecules enhances the mechanical strength and the Young's modulus of the resist film, effectively mitigating pattern collapse. The C2S resist achieved an 18 nm line/space (L/S) pattern and a 14 nm L/2S semi-dense pattern with EBL. Performance studies with EUVL yielded an impressive 14 nm half-pitch (HP) pattern with a remarkably low line-edge roughness (LER) of 1.7 nm. Extensive studies of the EUV exposure mechanism, conducted using in-situ quadrupole mass spectrometry (QMS) and X-ray photoelectron spectroscopy (XPS), demonstrated that the solubility switch of the resist material depends on the decomposition of the sulfonium groups and triflate anions.

The reaction site of aryl diazonium salt was restricted in the position of diazonium moiety, due to the intrinsic electrophilicity of diazonium moiety. Herein, we described an unprecedented chemoselective alkylation of Csp²-H of aryl diazonium salts with 1-iodo-3-pentafluorosulfanylbicyclo[1,1,1]pentane (SF₅-BCP-I). This novel alkylation of aryl diazonium salts provided an efficient access to various SF₅-BCP substituted aromatics that might have great potential application in the drug discovery. Mechanistic experiments and theoretical studies revealed that the intrinsic electrophilic SF₅-BCP radical resulted in the thermodynamic favorable radical addition on Csp²-H site rather than diazonium moiety of aryl diazonium salt.

A practical photocatalytic annulation-biselenylation strategy has been developed for the efficient synthesis of biselenium-substituted 1-indanones (38 examples in total) with generally good yields (up to 95%) and excellent stereoselectivity (>19 : 1 Z/E ratio) by employing enynones and diaryl selenides as starting materials under photosensitizer-free conditions. The reaction mechanism involves a cascade process comprising homolytic cleavage, radical addition, 5-exo-dig cyclization, and radical capture, enabling sequential formation of multiple bonds, such as C(sp³)-Se, C(sp³)-C(sp²), and C(sp²)-Se bonds, to rapidly construct molecular complexity. Notably, this approach demonstrates wide substrate compatibility and excellent tolerability towards various functional groups. It is further characterized by its remarkable efficiency in creating chemical bonds and achieving high atomic utilization of 100%.

The divergent synthesis of 2-quinolinones and indolin-3-ones through unprecedented Mo-catalyzed controllable carbonyl deoxygenative coupling and formal deoxygenative N—H insertion reactions was reported. By simply changing the molybdenum catalytic conditions, both product categories were produced in generally good yields and with high chemoselectivities from the same starting materials. This strategy was robust, convenient and ready for the rapid construction of diverse product libraries.

The reactions of potassium diazaphospholidinyl diazomethylide with phenylacetylene, acetonitrile, adamantyl phosphaalkyne, and styrene promptly form pyrazolide, triazolide, diazaphospholide, and pyrazolinide, respectively. The reaction mechanisms have been studied using DFT calculations. While the reactions with phenylacetylene and styrene proceed via stepwise pathways, those with acetonitrile and adamantyl phosphaalkyne follow concerted pathways. Additionally, the pyrazolide product readily undergoes N-functionalization, yielding methyl pyrazole, germanyl pyrazole, and copper pyrazolide complexes.

New chiral guanidine catalysts having axial chirality containing a methoxy group were synthesized. Subsequently, their catalytic ability was examined by applying the silylative kinetic resolution of racemic alcohols using chlorosilanes. Based on an X-ray crystallographic analysis of the catalysts, the functional role of the methoxy group was predicted, and the plausible reaction pathways and a transition state were described. It was also revealed that the existence of hydrogen bonding between the methoxy group on the catalyst and hydrogen atom at C-1 position of the substrates was of great importance for attaining high selectivity and reactivity. The proposed method is applicable to various acyclic aryl, heteroaryl, and normal-alkyl alcohols exhibiting medium to high s-values (s = 15–96, 15 examples).

Recycling polyolefin and other plastic mixtures encounters significant obstacles due to the intricate nature and economic inefficiencies of physically separating vast streams of mixed waste. Incorporating compatibilizers emerges as a viable strategy to diminish interfacial energy and bolster compatibility, ultimately yielding homogeneous products. In this contribution, polar polyolefins featuring metal dynamic cross-linking networks were synthesized by tandem polymerizing ionic cluster type polar monomers and olefins. Subsequent treatment with HCl aqueous solution and esterification with polyester precursors yields high-performance grafted polar polyolefins for mixed polymer compatibilizing. For PP/PC melting blends, adding 5 wt% of graft-modified polyolefin results in tougher blends that surpass the performance of corresponding virgin iPP in elongation at break (εb). Polar polyolefins containing sodium carboxylate groups play a dual role in compatibilizing PET/HDPE blends, acting both as compatibilizers and nucleating agents. Moreover, this strategy enables the production of grafted polyolefins comprising ternary polymers, which can be employed in compatibilizing ternary blends.

In recent years, significant breakthroughs in the enhancement of energy barriers (U_eff) and blocking temperatures (T_B) of lanthanide single-ion magnets (Ln^III-SIMs) have made high-density information storage and high-speed data processing at the molecular level increasingly feasible. As research on Ln^III-SIMs deepens, scholars are reevaluating polynuclear complexes to enhance their multifunctionality. Cyano bridge has emerged as a commonly used strategy for constructing polynuclear complexes. Notably, Ln^III-SMMs based on octacyanometallates exhibit diverse topological structures and magnetic interactions, providing new perspectives for developing ordered supramolecular assemblies and high-dimensional frameworks. Our review provides an exhaustive exploration of octacyanometallate-bridged {Ln^IIIM^IV/V} SMMs (M = Mo, W, and Re). We first systematically analyze existing knowledge of Ln^III-SMM bridging systems to establish a foundation for understanding their structure-property relationship. Subsequently, we categorize these complexes based on their ancillary ligands, offering insights into their functionality and the role of cyano bridges in mediating magnetic interactions between metal ions. Finally, we discuss potential strategies aimed at optimizing structures to further enhance SMM performance and functionality. We anticipate that a deeper comprehension of the magnetic characteristics of cyano-bridged lanthanide complexes will foster the development of functional and application-driven cyano-bridged Ln^III-based molecular systems.

The prevalence and spread of viral infectious diseases pose a grave threat to global public health, particularly resulting in a significant number of casualties. To curb the spread of infectious diseases, virus testing is one of the efficient and economical means, among which nucleic acid detection has the advantage of detecting viral infections at an early stage, even before symptoms appear. Rolling circle replication is a representative of enzyme-mediated nucleic acid isothermal amplification technology, which is characterized by its mild reaction conditions, no need for temperature control equipment, and high efficiency. This review provides a conceptual overview of the latest advances of rolling circle replication (RCR) and their applications in viral detection, focusing on the molecular design principles in different application scenarios. The first part briefly describes the significance and advantages of RCR in virus detection. The second part elaborates on the design principle and preparation strategy of RCR and its derivative technologies. The third part focuses on the various application scenarios in virus detection. In the end, we provide a perspective on the innovation of RCR in improving the accuracy and specificity of virus detection to cope with the challenges of infectious diseases that may arise in the future.