A synergistic bromide/photoredox co-catalyzed aza-(3+2) cycloaddition of aryl cyclopropanes with diazenes has been developed. This metal-free protocol enables the direct construction of structurally diverse pyrazolidines under mild conditions. The reaction features broad substrate scope, excellent functional group tolerance, and gram-scale feasibility. Mechanistic studies support a pathway involving bromine radical-induced homolytic substitution (SH2) at the cyclopropane ring followed by C-centered radical addition to the N=N bond, radical-polar crossover (RPC), and SN2 cyclization. This strategy overcomes the long-standing limitation of the use of simple aryl cyclopropanes in diamination cycloaddition reactions and provides a versatile approach to heterocyclic 1,2-diamies in a C(sp3)–C(sp3) bond difunctionalization process.

The exploration of unconventional functional group transfer reagents represents a significant advancement in the development of practical and atom-efficient synthetic methodologies. We herein report a novel bench-stable and modular N-chlorofluoroiodane-(III) reagent, CFBI, which facilitates the transfer of chlorine and fluorine atoms to diazonium compounds in a single-step reaction. This method affords medicinally relevant α,α-chlorofluoro ketones, amides, and esters in moderate to high yields with excellent chemoselectivity. CFBI, which features an N-chlorobenziodazolone framework, is readily synthesized in two steps with an overall yield of 64%. Its structure was fully characterized by NMR spectroscopy, ESI-HRMS, and X-ray crystallography. Combined experimental and computational studies reveal that this reaction follows a nonclassical mechanism. In the rate-determining step, the nucleophilic diazonium preferentially attacks the electrophilic chlorine atom instead of the iodane-(III), leading to the formation of a partially reduced iodane-(III) species E.

A formal total synthesis of 5/5/5/6 caged-like daphnenoid A was accomplished. The strategy involves a Morita-Baylis-Hillman reaction to construct a precursor for the key intramolecular Diels-Alder reaction (IMDA). Notably, the IMDA indicated opposite chemoselectivity when the configuration of stereocenter (C7) changed. Several intermediates we synthesized showed stronger anti-inflammation activities compared to daphnenoid A.

Discovery and application of reactive intermediates has prominently expedited the development of organic chemistry. In this respect, while ketene has been well recognized as a versatile intermediate for a wide range of transformations, practical application of difluoroketene remained virtually unrealized because of its highly reactive nature. Herein, we present a transition-metal-free approach for in situ generation of difluoroketene using difluorobromoacetylsilane as a precursor. The controlled release of chemically labile difluoroketene under mild conditions, achieved through desilylative β-elimination, establishes a foundation for successful development of its Belluš-Claisen rearrangement with allylic amines, Staudinger [2 + 2] cycloaddition with imines, [4 + 2] cycloaddition, as well as insertion into alcohols, amines, and thiols for their difluoroacetylation. A series of mechanistic experiments provide concrete support for the involvement of difluoroketene in these transformations.

The quinoxaline (Qx)-fused-core-based small molecular acceptors (SMAs) have garnered significant attention owing to their extremely low energy loss in organic solar cells (OSCs). However, excessive molecular stacking and poor processability limit up-scaling and operational stability. Herein, two novel SMAs, Qx2-D7F and Qx2-D10F, were synthesized by introducing multiple fluorine atoms into the Qx2 core. Theoretical and experimental results demonstrate that fluorine incorporation significantly alters local dipole moments and electrostatic potentials, thereby tuning energy levels and stacking modes. Compared with D18:Qx2 and D18:Qx2-D10F, D18:Qx2-D7F blends exhibit optimal phase separation and balanced charge mobility due to extended film-forming time and moderate donor-acceptor interactions. As a result, D18:Qx2-D7F devices reach a high PCE of 18.12%, with a VOC of 0.945 V and a low non-radiative loss of 0.197 eV. Ternary D18:L8-BO:Qx2-D7F devices yield 20.25% PCE. Fluorine substitution enhances SMAs processability, achieving 14.61% PCE in 1 cm2 large-area slot-die-coated PM6:Qx2-D7F devices, higher than PM6:Qx2 (10.45%). D18:Qx2-D7F devices also exhibit excellent thermal and photostability, with T80 lifetimes over 3500 and 2000 h. These results highlight that precise regulation of donor-acceptor intermolecular interactions with the multi-fluorination strategy enables significant improvements in the morphology and stability of OSCs.

Cycloadditions are described as either concerted or stepwise processes, where a catalyst can influence both the mechanism and the peri-, regio- and stereoselectivity. We report experimental and DFT-computational investigations that reveal the versatile reactivities of cross-conjugated unsaturated iminium-ion intermediates. These undergo cycloadditions with cyclic and linear dienes via both stepwise and concerted pathways, respectively, providing two distinct classes of enantioenriched cycloadducts. Activation of 2-formyl-1,3-cyclohexadiene with a chiral 1,2-diaminocatalyst generates an acyclic cross-conjugated iminium-ion intermediate, which by utilizing 4π-electrons, undergoes enantioselective inverse-electron-demand [4 + 2] cycloadditions with cyclic dienes via a stepwise mechanism, as well as indene and a styrene, affording cycloadducts in high yields and up to 96% ee. In contrast, only 2π-electrons of the cross-conjugated iminium-ion intermediate are involved in the [4 + 2] cycloaddition with linear dienes, proceeding via an ambimodal asynchronous concerted pathway, yielding decalin derivatives in up to 96% ee. The generality of this catalytic enantioselective concept is expanded to also include acyclic cross-conjugated iminium-ion intermediates, which react with both cyclic and linear dienes following the same two distinct reaction pathways. In contrast, the analogous iminium-ion, generated from 1-formylcyclohexene, does not react under the same conditions.

Fluoroorganic chemistry is one of the most hectic areas of current chemical research, exerting a profound effect on the most vital industries such as medicine, pesticide, and material science. Synthesis of fluorine-containing organic molecules, particularly those that bear C(sp3)-F bonds, remains a great challenge in modern chemical synthesis. Herein, we disclose a new strategy for the construction of a carbon-fluorine quaternary center, which was accomplished with the silver(I)-catalyzed intramolecular Wagner-Meerwein rearrangement fluorination of allylic gem-disubstituted alkene derivatives by using a hypervalent monofluoroiodine(III) reagent 1 (AFBI). Interestingly, the tunable five/six-membered heterocycle selectivity is achieved by the intramolecular Wagner-Meerwein rearrangement fluorination via a judicious choice of the group R1 attached to the C-C double bond. This versatile strategy features simple starting materials, mild reaction conditions, good functional-group compatibility, high bond-forming efficiency (e.g., one C-F and one C-O bond), and excellent chemoselectivity. The proposed reaction mechanisms and the roles of the catalyst AgBF4 were understood by control experiments and density functional theory calculations. (c) 2026 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Iodoarenes constitute an indispensable class of organic compounds with extensive applications across diverse fields. As versatile synthetic building blocks, iodoarenes are crucial to developing pharmaceuticals, agrochemicals, and functional materials. Their efficient synthesis has long attracted significant attention. Herein, we report a unique reagent system comprising the two-coordinate hypervalent iodine reagent (phenyliodonio)sulfamate (PISA) and molecular iodine (I2). By modulating solvent and reagent stoichiometry, this system enables mild electrophilic iodination of arenes with diverse electronic properties. It exhibits excellent functional group compatibility for the late-stage iodination of complex molecules, including pharmaceuticals and natural products. DFT calculations reveal that PISA acts as an effective halogen bond donor, promoting I-I bond cleavage in I2. Concurrently, intramolecular hydrogen bonding and halogen bonding interactions involving the nitrogen and oxygen atoms of the sulfamate ligand stabilize key reactive intermediates.

Chemoselective functionalization of hetero-gem-dimetalloid represents an attractive strategy in terms of diversity-oriented synthesis. In particular, desilylative functionalization of gem-silylboronate esters remains a challenging task and existing solutions heavily relied on ionic reactions. Herein, we report a desilylative functionalization of allylic gem-silylboronate esters with aldehydes under synergistic photoredox and chromium(II) catalysis. With different substrates, both α- and γ-functionalization are realized with exclusive regioselectivity and diastereoselectivity, which is dictated by the chair-like transition state of predominant isomer of CrIII allyl intermediate. Moreover, γ-functionalization products bearing CF2 unit are acquired when gem-difluoroalkene-containing substrates are employed. In the presence of chiral ligand, enantioselective allylation of aldehydes is successfully accomplished, affording alkenylated 1,2-diols after oxidative workup with excellent regio-, diastereo- and enantioselectivity. The current protocol displays wide substrate generality and broad functional group compatibility. In addition, diverse post-transformations converted obtained products into a variety of valuable structures.

A domino protocol for the concise preparation of functionalized quinolinone-fused pyrrolo[2,1-a]isoquinoline derivatives from formyl-phenylpropiolamides using tetrahydroisoquinolines was developed without using any catalyst or additive. This green strategy involved cascade intermolecular aldehyde-amine condensation/intramolecular [3 + 2] cycloaddition. Under benign conditions, a diverse range of favorable compounds were smoothly synthesized in good to high yields with diverse functional group compatibility and broad substrate scope.

High-speed data transmission requires the formation of fine and smooth Cu wiring, which inevitably causes a decline of interfacial bonding strength between Cu and the insulating dielectric layer. In this work, 4-aminothiophenol (4-ATP) is used as a bifunctional promoter for the interfacial adhesion between a Cu foil and a widely used Ajinomoto build-up film (ABF) without coarsening the Cu surface. It is found that the introduction of ascorbic acid (AA) accelerates the self-assembly process of 4-ATP on Cu surface, as monitored by in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS) and examined by cyclic voltammetry (CV). Peel strength tests and morphology analyses reveal that the AA-assisted 4-ATP SAM significantly enhances the interfacial adhesion between Cu and ABF, which is of practical significance in advanced packaging.

Compliant joints are widely used in precision positioning stages due to their nearly zero friction. A two-dimensional rigid-flexible coupling positioning stage (2D-RFCPS) containing multiple compliant joints is proposed to compensate for positioning errors caused by nonlinear friction, achieving long-stroke ultra-precision positioning. The kinetic and strain energies of the moving stages in the 2D-RFCPS are calculated based on the floating frame approach and the finite element method, respectively. These are used to establish the dynamic model of the 2D-RFCPS using the Lagrangian equation, revealing vibration coupling effects between the moving stages across six spatial directions. The accuracy of the dynamic model is validated through two comparative experiments. First, simulations under constant and harmonic forces are conducted using MATLAB and ADAMS, with the maximum root-mean-square error (RMSE) between the MATLAB and ADAMS results in displacement and velocity are 6.86E-4m and 2.9E-3m/s, respectively. Second, active disturbance rejection control (ADRC) algorithm is applied for point-to-point motion simulations and physical experiments, resulting in RMSE values of 8.80E-6m and 1.74E-4m/s in displacement and velocity, respectively. Additionally, the effectiveness of the dynamic model is demonstrated through vibration coupling analysis between the X-Tab and Y-Tab across six spatial directions. Notably, the Y-Tab rotation around the Z-axis is significantly influenced by the eccentric inertial torque, with the rotation amplitude increasing by 177.7

The thio-Belluš-Claisen rearrangement with difluoroketene is reported herein. By resorting to fluoride-initiated desilylative β-elimination of difluorobromoacetylsilane, a new protocol that enables controlled release of the unstable difluoroketene and its efficient capture by allyl thioether for the ensuing rearrangement is successfully developed. The presence of an electron-withdrawing group on the internal alkene site of allyl thioether is proven to be vital for this reaction by promoting the rearrangement through charge stabilization in the transition state.

The 1,3-difunctionalization of alkenes represents a pivotal transformation in organic synthesis. Herein, we report an innovative electrochemical strategy for the 1,3-difunctionalization of alkenes with aldehydes to access 1,4-diketones via convergent paired electrolysis. This methodology demonstrates remarkable versatility and successfully applies to a wide variety of aryl aldehydes, as well as structurally diverse allylbenzenes, while exhibiting exceptional efficiency, selectivity, and functional group compatibility, thereby underscoring its extensive applicability.

A novel approach to α-fluoroamides bearing a C–F quaternary stereocenter is reported herein. With sulfone installed as the activating group, an alkyl group as well as a fluorine atom was introduced successively under mild conditions. Subsequently, heterolytic fission of the C–S bond occurred smoothly under photoredox conditions to afford a tertiary radical, which then engaged in varied intramolecular cyclizations depending on substrate structure and condition applied, rendering sulfone an overall traceless activating group.

The mechanical flexibility and high conductivity of hydrogel electrolytes are crucial for their application in supercapacitors. In this study, we developed hydrogel electrolyte based on lignocellulose nanofibers (LCNFs) through nanofibrillation and self-catalytic gelation in a glycerinum/choline chloride/aluminum chloride hexahydrate (Gly/ChCl/AlCl3·6H2O) metal-based neutral deep eutectic solvent (DES) system. The lignin-Al3+ self-catalytic mechanism offered an eco-friendly and sustainable method for synthesizing hydrogel electrolytes, while enhancing their ionic conductivity. The high aspect ratio of LCNFs significantly improved the mechanical strength of the hydrogel electrolyte by facilitating the intertwining of LCNFs with acrylamide molecules. The resulting hydrogel electrolyte demonstrated exceptional mechanical strength (485 kPa), high ionic conductivity (26.1 ms/cm), strong adhesion (225 kPa), and excellent environmental stability (up to -80 °C). A supercapacitor assembled with this hydrogel showed a remarkable specific capacitance (200 F/g) and exhibited high sensitivity in electrical signal applications. This work demonstrates the transformation of wood fiber into functional lignocellulose-based materials, highlighting the high-value utilization of lignocellulose resources for energy storage and other applications.

Interface engineering of metal oxide/alloy/carbon composites could enhance NH3 dehydrogenation while weakening *N binding on Pt. In this work, we synthesized PtCoOx/C catalysts via a facile method, leveraging the synergistic effects of dual-interfaces - specifically, the "metal oxide-alloy" (PtCo-CoOx) and "alloy-carbon" (PtCo-C) interfaces. Both PtCo-CoOx and PtCo-C could synergistically modulate Pt's electronic structure, promoting the ammonia oxidation reaction (AOR). The electrochemical results reveal that PtCoOx/C achieves a remarkable current density of 18.4 mA cm-2 and exhibits superior stability compared to both PtCo/C and PtCo SS/C. The results highlight the critical role of dual-interface effects in enhancing the AOR.

Benziodazole-triflate, as a novel heterocyclic hypervalent iodine(III) reagent, was prepared from the reaction of hypervalent chloroiodine(III) with silver triflate under mild conditions. The structure of this new reagent was elucidated by NMR spectroscopy and X-ray crystallography, and its reactions with diverse α-electron withdrawing group substituted carbonyl compounds were investigated. The results implied that benziodazole-triflate could be selectively used as both a 2-iodobenzamido-transfer reagent for the synthesis of oxazole compounds, and a triflate-transfer reagent for the triflation of β-keto-sulfones. Ionic mechanistic pathways, supported by Density Functional Theory (DFT) calculations, were proposed to account for the divergent selectivities of the transformations.

Aflatoxin B1 (AFB1) and its metabolite aflatoxin M1 (AFM1) are stable and carcinogenic mycotoxins that are commonly found in dairy products, posing serious food safety concerns. However, conventional degradation methods face limited degradation efficiency and high energy demand. Here, we develop an innovative polyvinylidene fluoride (PVDF) composite membrane incorporating Fe/Co-based metal-organic frameworks (MOF) (Named Fe/Co-MIL-88B(NH2)) and CaO2 for targeted aflatoxin removal from milk. This system integrates two synergistic mechanisms: (1) hierarchical porous MOF structures enabling superior aflatoxin adsorption capacity and peroxidase-like catalytic activity, and (2) CaO2 acts as a controllable-release H2O2 donor, supplying a steady flux of reactive oxygen species without the addition of exogenous H2O2. Moreover, the PVDF membrane with mechanical stability offers uniform immobilization of active components, which prevents the aggregation of nanozymes. As a result, the integrated membrane achieves high degradation efficiency for AFB1 and AFM1, exceeding 95% within 60 min. By eliminating external oxidant addition and minimizing collateral nutrient damage, the technology demonstrates remarkable operational stability (>10 cycles) and milk quality preservation capability. This breakthrough establishes an efficient and reusable detoxification method, providing new opportunities for mycotoxin mitigation in dairy products through spatiotemporal control of reactive oxygen species.

Perfluoroalkyl alkenyl iodides (PFAIs) are emerging as highly reactive, storage-stable, and multifunctional fluoroalkyl-bearing reagents, facilitating the manufacture of value-added organofluorides through multi-halo-functionalization. Herein, we developed a water-involved 1,3-aminoxylation of PFAIs with sulfonamides for the chemo-, regio-, and Z-stereoselective synthesis of valuable β-fluoroacyl vinylamines. This reaction proceeded via a sequential deiodoamination and defluoroxylation process under transition-metal-free conditions, featuring a broad substrate scope and good functional group tolerance. Compared to reported methods, some drawbacks, such as multistep manipulation, harsh reaction conditions, the need for expensive catalysts, and the use of toxic/sensitive reagents, could be eliminated. Furthermore, the synthetic potential of this method was demonstrated through scale-up synthesis, postfunctionalization of complex molecules, and ready transformation of the products.