Saturated bridged bicyclic frameworks, such as bicyclo[1.1.1]pentanes (BCPs), bicyclo[2.1.1]hexanes (BCHs), and bicyclo[3.1.1]heptanes (BCHeps) can replace planar benzene rings with the concept of escape from flatland, which can enhance the pharmacokinetic and physicochemical properties of drug candidates and have attracted more and more research interest in recent years. Several outstanding studies have been reported on the diastereoselective dearomative [2n+2a] cycloadditions of indoles with bicyclobutanes to form fused BCHs. Here, we report a unique approach for synthesizing chiral indoline-fused BCHs from 3-nitroindoles and bicyclo[1.1.0]butanes (BCBs) in the presence of a palladium catalyst. The palladium-catalyzed asymmetric [2n+2a] cycloadditions were achieved through a key zwitterionic n-allyl-Pd intermediate under mild conditions, affording the products in good yields up to 99% with excellent enantiomeric ratio (er) values up to 99:1. The reaction mechanism and the origin of stereoselectivity were investigated by DFT calculations.

Unlike the widely reported fluorophore-biomacromolecule systems in nucleic acid testing and immunoassay, organic afterglow luminophore-biomacromolecule conjugates and complexes remain rarely explored. Here we report the observation of organic afterglow from aqueous solutions of luminophore-protein conjugates and complexes at freezing temperature, named as afterglow ice for abbreviation. Reliable N-hydroxysuccinimide ester protocol, as well as beta-diketone chemistry, are applied for protein labeling to form luminophore-protein conjugates, which exhibit intriguing afterglow at freezing temperature. Control experiments reveal that hydrophobic interaction and covalent linkage between luminophore and protein can protect organic triplet excited states from quenching. In the case of luminophore-protein complex, we observe the switching-on of organic afterglow after specific recognition of streptavidin by biotinylated luminophore, which is the example of specific recognition and sensing of biomacromolecules by organic afterglow emitters. Although it is not yet a mature technology for biomedical applications, this study represents the initial step of organic afterglow materials towards bio-labeling and bioassay fields, as well as expanding the application scenarios of bioactive products.

A hypervalent iodine-mediated C-H azidation is reported that enables direct, regioselective installation of azido groups onto diverse arenes. The method tolerates a wide range of functionalities and operates under mild conditions. Its value is demonstrated through late-stage azidation of drug intermediates and functional molecules, providing versatile azidoarenes that undergo efficient downstream transformations, including reduction and click conjugation. This concise and scalable strategy offers a practical platform for arene modification and rapid molecular diversification.

Organic afterglow materials hold great promise for applications in bioimaging, sensing, and information encryption, yet the construction of advanced nanostructures like vesicles with long-lived luminescence remains a formidable challenge. We pioneer the construction of organic afterglow vesicles via polymerization-induced self-assembly (PISA), integrating a thermally activated delayed fluorescence (TADF)-type organic afterglow emitter into block copolymer nanostructures. The resulting vesicles exhibit well-defined hollow morphologies, uniform size distribution, and high solid content up to 20%. They display significant room-temperature afterglow with an emission lifetime exceeding 200 ms and a photoluminescence quantum yield (PLQY) of 20.8%. The afterglow mechanism is attributed to efficient TADF with a moderate intersystem crossing rate, where the triplet excited states are excellently protected by the rigid glassy vesicle walls. Moreover, the vesicles show rapid, reversible, and repeatable oxygen-responsive behavior, making them promising for reusable oxygen sensing. This work establishes a versatile and scalable strategy for designing functional organic afterglow nanostructures with potential applications in bioimaging, sensing, and environmental monitoring.

A highly efficient, iron(III)-BPsalan complex-catalyzed asymmetric 1,3-dipolar cycloaddition of nitrones and alpha,beta-unsaturated acyl imidazoles has been developed to afford isoxazolidine (31 examples) and isoxazoline derivatives (13 examples) in moderate to excellent yields (up to 99%) and excellent stereoselectivity (up to 99% ee and >20:1 dr). The reaction proceeds readily in acetone under air conditions, maintaining high efficiency and selectivity.

The development of a biocompatible antidote that can efficiently neutralize the anticoagulation activity of both unfractionated heparin (UFH) and low-molecular-weight heparins (LMWHs) represents an unmet medical need. Here, we report that a piperazine-derived tetracationic macrocycle can efficiently neutralize both UFH and LMWHs, including dalteparin, enoxaparin, and nadroparin. In vitro and in vivo assays reveal that the compound outperforms protamine, exhibiting significantly improved neutralization activity, a broad therapeutic window for all heparins, and high biocompatibility, which is confirmed by its very low coagulation and hemolysis effect, as well as a high therapeutic index (20.5), defined as the ratio of the maximum tolerated dose to the effective therapeutic dose. Molecular dynamics simulations indicate that binding may occur through interlocked threading and direct contact patterns, which are stabilized by intermolecular hydrogen bonding and ion-pair electrostatic attraction.