Herein, a highly enantioselective formal synthesis of (+)-Treprostinil via the interphenylene prostaglandin E₁ scaffold was described. The chiral multi-substituted cyclopentanone was constructed via a [Rh(Duanphos)SbF₆-catalyzed asymmetric enyne cycloisomerization and a copper hydride-mediated conjugate reduction. In addition, a new type of interphenylene prostaglandin scaffold was obtained via a formal Alder-ene reaction in high yield with excellent chemoselectivity.

The transition metal-catalyzed acceptorless dehydrogenative coupling of alcohols and amines is one of the attractive and important strategies for the construction of C=N bonds from the perspective of environmental friendliness and economy. Herein, we report the synthesis of four novel phosphine-free cobalt(II) complexes (Co-1—Co-4) with N,O-bidentate ligands incorporating N-oxide units and their catalytic activity in acceptorless dehydrogenative coupling of benzylic alcohols and aryl amines. X-ray diffraction analyses revealed that the central cobalt atoms in three of the cobalt complexes (Co-1, Co-2, Co-4) were six-coordinated and adopted an octahedral geometry configuration. Catalytic evaluation of cobalt complexes demonstrated that Co-4 exhibited higher activity than the other three cobalt complexes. This system could provide a series of corresponding imine products with good functional groups compatibility and high yields. Especially, the use of phosphine-free and inexpensive cobalt complexes, along with readily accessible N,O-bidentate ligands featuring N-oxide moieties, offers significant advantages for this reaction.

5-Methylcytosine (5mC) plays pivotal roles in numerous biological processes. To gain a deeper understanding of the biological functions of 5mC, it is essential to develop methods for its quantitative analysis. Herein, we engineered the repressor of silencing 1 (ROS1) protein to enhance its glycosylase/lyase activity towards 5mC, resulting in an engineered ROS1 (eROS1) protein that can effectively excise 5mC from DNA. Using eROS1, we developed a method termed engineered ROS1-mediated quantitative (eRMQ) analysis, for the locus-specific quantification of 5mC in genomic DNA. This method capitalizes on the ability of eROS1 to selectively cleave 5mC, which creates a one-nucleotide gap. The presence of this gap hinders the extension of DNA polymerase, leading to a reduction in extension products that can be evaluated using real-time quantitative PCR (qPCR). The limit of detection for the eRMQ method was as low as 1 fM. Using the eRMQ method, we achieved the quantitative analysis of 5mC at individual sites within genomic DNA and demonstrated a significant reduction in 5mC levels in lung cancer tissues compared to adjacent normal tissues. Taken together, this study introduces eRMQ method for the quantitative analysis of 5mC in DNA, offering a valuable tool for exploring epigenetic regulation in human diseases.

The cycloaddition and annulation reactions offer a powerful method toward various important substituted 3,4-dihydro-2H-pyran architectures. Nevertheless, the transformation for preparing fused-polycyclic ones still remains challenging yet highly desirable until now. Herein, we report a novel formal [3+3] cascade cyclization reaction to provide lactam-fused 4-fluoroalkylated 3,4-dihydropyran skeletons bearing three contiguous tertiary carbon centers via copper catalysis. Of note, these annulations proceeded in an exclusively diastereoselective manner through successive inert C(sp²)-Cl and C(sp³)-H functionalization, which exhibited highly site-selectivity and stereoselectivity. Additionally, evaluations on biological activities of the obtained products revealed that several products display inhibitory activity against Siha and H1975 cancer cell lines.

In this study, we successfully developed ion pair catalysts consisting of chiral bisguanidinium (BG) cations and non-chiral sulphonated phosphine-palladium complexes as counterions. These ion pairs catalyzed allylic alkylation reactions with excellent enantioselectivities. Furthermore, these reactions can be easily performed on a gram-scale, demonstrating their potential for industrial applications. We were able to obtain ¹H NMR of the ion pair catalyst and identified the ³¹P NMR of the sulphonated phosphine-palladium complex.

Aminocarbonylative heteroannulation of unsaturated hydrocarbons with amines and CO has become a key transformation in organic synthesis to build N-heterocycles. In this report, a new palladium-catalyzed aminocarbonylative [3+2+1]/[4+2] heteroannulation of allylamines with CO and 4-en-1-yn-3-yl acetates for the synthesis of 1,7,8,8a-tetrahydroisoquinolin-3(2H)-ones has been developed. The method enables the construction of two new six-membered rings in a single reaction step leading to the formation of the isoquinolinone scaffolds, featuring excellent selectivity, good functional group compatibility and broad substrate scope. A possible mechanism involving Pd-catalyzed isomerization to form the allenyl-Pd intermediate, aminocarbonylation and cycloaddition was proposed.

Nitrofuran antibiotics threaten human health and the environment due to their toxicity and persistence. Their detection is challenging due to low concentrations and interference, while fluorescence sensing offers superior sensitivity and selectivity for effective monitoring. In this work, a novel halogen-bonded organic framework, XOF-TPEM, was introduced, constructed using an imidazole-based ligand AIE molecule, TPEM. The framework was successfully characterized by various techniques, including ¹H NMR, PXRD, XPS, FT-IR, HRTEM, SAED, SEM and EDS, confirming its excellent crystalline structure. As TPEM is an electron-donating AIE fluorophore, the fluorescent XOF-TPEM demonstrates potential as a selective sensor for electron-deficient nitrofuran antibiotics. Experimental results show that it exhibits high sensitivity and selectivity for detecting nitrofurans such as NFT, FZD, FLD, and NFZ, with LODs of 9.7 ppb, 11.0 ppb, 19.7 ppb, and 236.1 ppb, respectively. Mechanistic studies indicate that the outstanding fluorescence detection performance is attributed to the inner-filter effect occurring between XOF-TPEM and the nitrofuran antibiotics. Through comparison with the sensing performance of a pyridine-based XOF, the superiority of imidazole ligands in constructing XOFs is demonstrated. This study presents a novel luminescent halogen-bonded organic framework and highlights the superiority of imidazole-based halogen-bonded organic frameworks, underscoring their significant potential for expanding their functional applications.

The [2+1] cycloaddition of alkynes with fluoroalkyl carbenes represents the most straightforward approach for constructing fluoroalkylated cyclopropenes. However, until now, this strategy has not been applicable to difluoromethyl carbene, as its precursor, difluoromethyl diazomethane, tends to undergo [3+2] cycloaddition with alkynes to form pyrazoles. This study presents the first example of copper-catalyzed cyclopropenation of alkynes with difluoromethyl carbene, employing difluoroacetaldehyde triftosylhydrazone as the carbene precursor. A wide range of internal and terminal alkynes, featuring diverse functional groups, were efficiently converted into the corresponding difluoromethyl cyclopropenes in good to high yields. Mechanistic investigations, supported by DFT calculations, revealed that the bulky Tp^Br3Cu(NCMe) catalyst plays a pivotal role in facilitating the cyclopropenation of alkynes with difluoromethyl carbenes via a concerted pathway.

More modifiable sites on the nucleoside motif may need to be explored for developing novel (p)ppGpp molecular tools. Herein, we report for the first time that the C7-substituted deazapurine nucleoside triphosphates bearing small modifications as substrates could be effectively accepted by Rel_Seq^NTD protein to react with ATP to give pppGpp derivatives with 65%—89% yields. Further structural derivatization via metal-coupling reaction was performed to produce C7-substituted GTP derivatives with larger bulkiness, and those GTP derivatives were also proven to be good substrates of Rel_Seq^NTD protein. Alkynyl modified pppGpp could be coupled with probes by click reactions as the potential molecular tools for fishing proteins in biological research. We further explored whether the C7-alkynyl-pppGpp (pppG^Epp) could be recognized by pppGpp interaction proteins. A micromolar level binding affinity (with a K_D value of less than 10 μM) between pppGpp(pppG^Epp) and its binding proteins was obtained from the Isothermal Titration Curve (ITC). All those illustrate that these easily accessible functionalized C7-substituted pppGpp derivatives were suitable tools for further exploring the molecular interaction between pppGpp and its binding proteins.

A one-pot transformation of aliphatic and aromatic tertiary amines to novel fluorinated enaminones has been developed, utilizing perfluoroalkyl ether carboxylates (PFECA salts) featuring “–CF₂O–” units as the fluorine-containing reagents. Carbonyl fluoride, acyl fluorides and anhydrides by thermal decomposition of these PFECA salts were proposed to act as key active species that trigger the tandem oxidation–acylation process of tertiary amines, through enamine intermediates.

Research into controlling the self-assembly of discrete porous organic cages (POCs) with specific geometries and functions is difficult, but important for understanding their structure-property relationship, as well as self-assembly behavior in supramolecular chemistry. Herein, we report the self-assembly of two POCs based on the same tetraformyl-functionalized calix[4]resorcinarene (C4RACHO) and 2,4-diaminophenol dihydrochloride (DAP) organic building blocks, including a [3+6] triangular prism (CPOC-201-OH) and a [4+8] square prism (CPOC-401-OH), as determined by single X-ray crystallographic analysis. Both POCs exhibit large intrinsic cavities, rich oxygen sites, and high porosity with Brunauer–Emmett–Teller (BET) specific surface areas up to 966 m²·g^–1. Owing to such virtues, both cages can effectively capture iodine in aqueous media with removal rate > 99% within 2 min.

Chiral γ-amino acids are among the most valuable and ubiquitous structural units in natural products, pharmaceuticals and many physiologically active compounds. Herein, we demonstrate a convenient synthetic approach to chiral γ-amino acid structures via an asymmetric aryl-aminoalkylation of alkenes enabled by a dual photoredox/nickel catalysis. Taking advantage of the mild and redox-neutral condition, high levels of enantiocontrol of α-carbonyl benzylic stereocenters are obtained. Experimental and computational mechanistic studies were performed to gain insights into the mechanism and origin of enantioselectivity. The results reveal that the reaction follows a Ni(0)/Ni(I)/Ni(III)/Ni(I) catalytic cycle and C–X bond oxidative addition is the enantiodetermining step.

The development of high-performance cathode materials through rational heterointerface engineering remains pivotal for advancing hybrid supercapacitors (HSCs) technologies. Here, we construct a three-dimensional ternary heterostructure composite Ni(OH)₂/NiAl LDH/rGO (N-OH/NA/rG) by sequential integration of metal-organic frameworks (MOF)-derived Ni(OH)₂, NiAl LDH and reduced graphene oxide (rGO). The covalent anchoring of NiAl LDH nanosheets on oxygen-functionalized rGO substrates mitigates restacking issues, establishing a conductive network with enhanced charge transfer kinetics. The alkaline etching of Ni-MOF precursors preserves their hierarchical porosity while converting to pseudocapacitive Ni(OH)₂. Synergistic effects among components yield increased active site density, dual charge storage mechanisms, and optimized ion diffusion pathways. The optimized composite achieves a high specific capacitance of 1481.7 F/g at 1A/g, along with excellent rate capability and cycle performance, establishing a new paradigm for designing multi-component heterostructure electrodes through MOF-derived interface engineering. Furthermore, the N-OH/NA/rG//AC HSC device demonstrates a high power density and energy density, coupled with long-term cycle stability, underscoring the substantial potential of N-OH/NA/rG as a cathode material for HSCs.

RNA modifications greatly expand the functional diversity of RNA molecules, impacting RNA's stability, folding, and interactions with other biomolecules. These modifications play critical roles in cellular processes and are increasingly linked to disease states. Developments in mass spectrometry (MS), nuclear magnetic resonance (NMR), and chemical probing techniques have provided insights into the mechanisms and functions of RNA modifications. Combining these experimental approaches allows researchers to explore the complexities of RNA modifications and their effects on RNA structure and dynamics. This review highlights recent progresses in the field and examines how the integration of MS, NMR, and complementary techniques is advancing our understanding of RNA modifications and their biological significance.