Chinese Journal of Chemistry最新文献

Herein, we report an efficient and practical strategy for the facile assembly of functionalizable conjugated dienes through skeletal editing of alkynyl diazoketones enabled by a traceless 2-pyridyloxy group. Conjugated dienes are important structural motifs and versatile synthetic building blocks, yet the stereodefined preparation of highly substituted dienes bearing a readily transformable functional handle remains challenging. In this protocol, alkynyl diazoketones react with 2-pyridone-derived N,N-acetals under mild Lewis-acid-promoted conditions to furnish polysubstituted conjugated dienes with useful chemo-, regio-, and stereoselectivity. The readily available 2-pyridyloxy moiety plays a dual role: it facilitates the multiple rearrangement sequence and remains in the products as a versatile handle for further diversification. The reaction exhibits broad substrate scope, tolerating alkynyl diazoketones bearing electron-donating and electron-withdrawing aryl substituents, heteroaryl and alkyl groups, and terminal alkynes, as well as N,N-acetals derived from substituted pyridones, pyrimidines, and various secondary amines. In addition, a convenient one-pot three-component protocol can be performed directly from an acetal amine, 2-pyridinone, and an alkynyl diazoketone without isolation of the intermediate N,N-acetal. The synthetic practicality of the method is further demonstrated by gram-scale preparation and diverse downstream transformations of the resulting dienes. In particular, the 2-pyridyloxy group can be replaced by sulfur, aryl, and alkenyl substituents through substitution or cross-coupling reactions, can enable installation of a complex cholesterol-derived fragment, and can also be removed reductively. The structure of representative product 3a was confirmed by single-crystal X-ray diffraction, supporting the proposed connectivity and nitrogen-initiated reaction pathway. Mechanistically, the transformation is proposed to proceed through Wolff rearrangement of the alkynyl diazoketone to an alkynyl ketene, nitrogen-initiated nucleophilic addition of the N,N-acetal, subsequent 1,5-migration to an allenamide intermediate, and a final [3,3]-sigmatropic rearrangement to generate the conjugated diene framework. Overall, this strategy provides a modular, scalable, and practical platform for accessing structurally diverse and readily functionalizable conjugated dienes.

Controlling film-formation kinetics remains a central challenge for optimizing morphology evolution and charge-generation processes in organic solar cells (OSCs). Herein, we develop a facile molecular engineering strategy to regulate film-formation kinetics through tetraphenylethylene (TPE) functionalization and design a new non-fullerene acceptor, BTP2F-TPE. The incorporation of bulky TPE units introduces pronounced steric hindrance, effectively suppressing excessive molecular aggregation and modulating intermolecular interactions during film formation. As a result, the D18:BTP2F-TPE blend exhibits a substantially higher solution-to-film transition rate (5.00 s^-1) than the D18:L8-BO counterpart (3.33 s^-1), leading to a more favorable phase-separated morphology. When incorporated as a third component into D18:L8-BO, BTP2F-TPE enables the ternary blend to achieve enhanced exciton dissociation, more efficient charge collection, and reduced non-radiative energy loss (0.210 eV). Consequently, the ternary device delivers a power conversion efficiency of 20.28%, with an open-circuit voltage of 0.907 V, a short-circuit current density of 27.72 mA·cm⁻², and a fill factor of 80.62%. Femtosecond transient absorption spectroscopy reveals accelerated hole transfer at the donor–acceptor interface, supporting the improved charge-generation dynamics observed in the ternary system. This work demonstrates that manipulating film-formation kinetics through steric side-chain engineering represents an effective strategy for optimizing active-layer morphology and advancing high-performance organic photovoltaics.

Traditional inorganic single-crystal scintillators face several adverse conditions, such as high cost, complex process and poor flexibility. To avoid these shortcomings, in this work, the low-cost benzyl bromide is used to efficiently synthesize the 0D organic-inorganic hybrid copper(I) halide compound Cu₅I₄Br₃(bz-ted)₂ (Compound Y) by the room-temperature solution method. The yields of the ligand (95%) and the scintillator (97%) are nearly 100%, and a single-batch production of 10.29 g is achieved, while the cost of the ligand raw material is drastically reduced. This material has an “all-in-one” (AIO) structure, with intramolecular π···π stacking interaction and Cu···Cu cuprophilic interactions together enhancing structural rigidity, resulting in its remarkable thermal, air, and light stability. Notably, Compound Y exhibits excellent yellow light-emitting properties with an outstanding photoluminescent quantum yield (PLQY = 90.66%) and an ultrahigh external quantum efficiency (EQY = 81.59%), which is investigated to be the emission from the self-trapped excitons (STEs). Moreover, it has favorable scintillation properties, with a low detection limit of 2.426 μGy_air·s⁻¹ and a satisfactory spatial resolution of 17.7 lp·mm⁻¹. When blended with styrene-ethylene-butene-styrene (SEBS) to fabricate the flexible scintillation screen, it can withstand 200% stretching and 0°–90° bending, with no halo distortion in imaging. This work not only promotes the commercial application of AIO-structured materials, but also provides a new approach for the large-scale fabrication of low-cost and high-performance flexible X-ray scintillators.

An unprecedented nitrene-induced skeletal editing of benzodithiol-3-ones is demonstrated herein, which constitutes the first example of S-to-N atom swap of benzodithiol-3-ones. The Pd/C catalyst demonstrated outstanding catalytic performance in this transformation by utilizing azides as the nitrene precursors to enable efficient desulfurization and nitrogen insertion of benzodithiol-3-ones. The proposed reaction mechanism for this Pd-catalyzed skeletal remodeling of benzodithiol-3-ones is further supported by density functional theory (DFT) calculations. The current Pd-catalyzed S-to-N atom exchange reaction proceeds under mild conditions with operational simplicity, eliminating the need for inert gas protection, which endows the streamline assembly of diverse benzo[d]isothiazol-3(2H)- ones with excellent functional group compatibility in decent yields. Moreover, this nitrene-induced skeletal editing strategy is amenable to late-stage functionalization of complex azides, thereby facilitating access to benzo[d]isothiazol-3(2H)-ones decorated with pharmacologically relevant scaffolds.

Chemical N-glycosylation is a crucial step in the synthesis of complex N-glycosides, particularly nucleosides. However, traditional carbohydrate chemistry often relies heavily on protecting groups, which can lead to cumbersome, time-consuming substrate preparation. Herein, we present a protecting-group-free glycosylation strategy that utilizes unprotected sugars as glycosyl donors through an N-bromosuccinimide (NBS)-mediated Mitsunobu reaction. This protocol features elimination of protection-deprotection manipulations, a broad substrate scope (compatible with a variety of unprotected monosaccharides, including ribose, arabinose, mannose, fructose, rhamnose, lyxose, xylose, galactose, glucose, and fucose), and excellent 1,2-trans-stereoselectivity. Importantly, this method has been successfully used for monosaccharide composition analysis of polysaccharides in traditional Chinese medicine (TCM).

Semi-transparent organic photovoltaics (ST-OPVs) suffer from an inherent trade-off between power conversion efficiency (PCE) and average visible transmittance (AVT). Here, we report a synergistic solution-processed strategy that concurrently optimizes the active layer composition and transparent electrode architecture to achieve a record solution-processed light utilization efficiency (LUE). Reducing the donor content in bulk heterojunctions represents an effective strategy to enhance the AVT, yet inevitably incurs severe efficiency penalties arising from disrupted charge transport and enhanced recombination. By incorporating a tert-butyl-functionalized 4-PACz derivative (tB-4P) into a donor-diluted bulk heterojunction, we suppress trap-assisted recombination and rebalance charge transport, recovering both the fill factor and short-circuit current density. Complementarily, a sandwich-structured ZnO/AgNW/ZnO composite electrode—employing optimized long aspect-ratio silver nanowires—is integrated with a solution-processed PMMA optical coupling layer and an anti-reflection coating to enhance photon harvesting and transparency. The resulting donor-diluted ST-OPV device delivers a PCE of 10.41% and an AVT of 48.0%, yielding a record LUE of 5.00% among solution-processed ST-OPVs reported to date. This work establishes a scalable pathway toward high-performance photovoltaic windows and building-integrated photovoltaics.

Acenaphtho[1,2-b]quinoxaline imide (AQI)-based shamrock-shaped non-fullerene acceptors (NFAs) have garnered significant attention in the field of organic solar cells (OSCs) due to their high open-circuit voltage (V_OC) exceeding 0.95 V. Improving the short-circuit current density (J_SC) and fill factor (FF), while maintaining a high V_OC, remains a pivotal challenge for this kind of emerging materials. Herein, three A'–DAD–A” type NFAs with asymmetric end-group architecture, AQI13, AQI13-b, and AQI13-c, were developed, where IC-2F was used as A' unit, and IC-1F, NC-1F and NC-2F were utilized as A” units, respectively. The intermolecular packing mode is regulated through this end-group modification strategy, thereby improving the J_SC and FF. Meanwhile, a balance in the trade-off relationship between J_SC and V_OC was established by modulating the intramolecular charge transfer (ICT) effect through asymmetric design. Consequently, the D18/AQI13, D18/AQI13-b and D18/AQI13-c layer-by-layer (LBL) devices demonstrate high PCEs of 17.78%, 17.95% and 19.07% with high V_OC of 0.986 V, 0.973 V and 0.958 V, respectively. In addition, D18:L8-BO:AQI13-c-based ternary OSCs realized an improved PCE of 20.20% in comparison with the binary device (PCE = 19.37%). This work offers a viable strategy for designing shamrock-shaped NFAs for high-voltage and high-performance binary and ternary OSCs.