The oxidative addition of electrophiles to transition metals is a fundamental step in transition-metal-mediated cross-coupling reactions. Although the mechanism of transition-metal-enabled C–X bond cleavage has garnered significant attention due to its impact on reaction selectivity and reactivity, the preceding association step between the electrophile and metal has long been underappreciated, particularly with regard to its kinetic effects. Here, we report and validate an associative electrophile-alkene exchange (E_AA) strategy using nickel(0)-alkene complexes. This approach shifts the rate-determining step from C–X bond cleavage to electrophile-alkene exchange. By doing so, it enables selective recognition of C(sp²)-electrophiles based on their coordination kinetics rather than bond dissociation energies, thereby facilitating the selective oxidative addition of C–F bonds over more reactive C–Cl, C–Br, and C–I bonds. Mechanistic studies reveal that the selective coordination of C(sp²)-electrophiles depends on the coordination propensity of the pre-coordinated alkene and the supporting ligand on the nickel(0) complex. This strategy not only complements the traditional reactivity trends of C–X bonds in oxidative addition but also provides a foundation for the rational design of catalysts and the development of more efficient chemical processes.

Chiral 1,4-diynes serve as important synthetic building blocks; however, general and efficient catalytic asymmetric strategies for their direct assembly from readily available propargylic chlorides and alkynes remain underdeveloped. Herein, we report a copper-catalyzed enantioselective alkynylation of racemic propargyl chlorides with terminal alkynes, enabled by a Ugi's amine-based tridentate f-PNN ligand featuring planar chirality. The catalytic system under mild conditions affords a variety of enantioenriched 1,4-diynes in high yields and excellent enantioselectivities, with wide functional group tolerance. Preliminary mechanistic studies support that the reaction proceeds through a radical pathway, and density functional theory (DFT) calculations revealed the key noncovalent interactions between the ligand and substrate which are responsible for the high enantiocontrol. We have demonstrated that the enantioenriched 1,4-diynes can be converted into a variety of synthetic useful compounds, including a triazole, a terminal alkyne, a chiral compound with a tertiary chiral center bearing three all alkyl substituents, and enynes with controlled E/Z selectivity. Furthermore, we have successfully applied our method to the formal synthesis of a gonadotropin-releasing hormone (GnRH) antagonist.

Chiral organic emitters with narrowband emission are highly desirable for next-generation circularly polarized organic light-emitting diodes (CP-OLEDs), yet their simultaneous realization of high efficiency, excellent color purity, and pronounced chirality remains a significant challenge. Here, we report a pair of green multiple-resonance boron–nitrogen (MR-BN) emitters in which chirality is introduced by a simple asymmetric spiro-acridine (SA) motif. This design preserves the rigid MR framework, affording intense green emission (λ_em = 516 nm) with a narrow full width at half maximum (FWHM) of 25–26 nm and high photoluminescence quantum yields, while the bulky SA unit effectively suppresses aggregation in the solid state. The chemically fixed geometry further imparts intrinsic chirality, leading to mirror-image circular dichroism and distinct CPL signals with |g_PL| values on the order of 10^–4. When incorporated into OLEDs, both enantiomers exhibit complete host–guest energy transfer, outstanding color purity with CIE coordinates of (0.143, 0.706) and (0.147, 0.687), and external quantum efficiencies of up to 24.1% and 23.2%, among the highest reported for green chiral emitters. This work presents a simple yet powerful molecular design strategy to integrate narrowband emission and chirality in MR systems, providing a promising pathway toward efficient, high-color-purity CP-OLEDs.

We report an efficient strategy for constructing indole-fused eight-membered heterocycles via a rhodium(III)-catalyzed NH-indole-directed C–H activation/[5+3] annulation of readily available 7-phenylindoles with methyleneoxetanones. This method provides direct access to benzo[4,5]azocino[3,2,1-hi]indole scaffolds, a structural motif of high relevance in natural products and bioactive molecules, yet synthetically underdeveloped. The reaction proceeds under optimized conditions using [Cp*RhCl₂]₂ (2.5 mol%) as the catalyst in methanol at 60 °C, delivering the disubstituted acrylic acid intermediates in good yields. A subsequent intramolecular amidation, mediated by TsCl/DMAP at room temperature, furnishes the eight-membered lactams in moderate to excellent yields. Salient features of this work include: (1) the use of the NH-indole group as an intrinsic directing group for chemoselective C–H activation; (2) the streamlined assembly of 1,7-fused eight-membered heterocyclic systems, expanding the toolkit for accessing medium-sized N-heterocycle; (3) broad substrate scope, tolerating diverse functional groups (e.g., CF₃, OMe, Cl, CN, CO₂Me, NPh₂, SiMe₃); (4) demonstrable synthetic utility through a gram-scale synthesis (up to 5 mmol) and a one-pot procedure without isolation of disubstituted acrylic acid intermediates; (5) Isolation and crystallographic characterization of two key rhodacyclic intermediates (a six-membered C–H/N–H cleaved species and an eight-membered alkene-insertion intermediate), confirming their role in the catalytic cycle; and (6) density functional theory (DFT) calculations that provide mechanistic insights, revealing that the transformation proceeds via a kinetically and thermodynamically favored β-oxygen elimination pathway, while the competitive β-hydride elimination is energetically disfavored.

Meeting the growing demand for clean and sustainable energy requires the development of efficient light-driven catalytic technologies capable of converting solar energy into chemical value. Photocatalysis represents a particularly attractive strategy. However, the rational design of photocatalysts that combine cost-effectiveness, long-term stability, and high activity remains a major challenge. Many existing systems suffer from limited visible-light absorption or inefficient separation of photoinduced charges, which restricts their practical applicability. In this work, we reported an integrated catalytic system (complex 1) in which a novel triphenylamine (TPA) group was introduced into a copper-based cyclic trinuclear complex (CTC). The introduction of the strong electron-donating TPA unit markedly enhanced visible-light absorption and promoted efficient charge separation within this collaborative system. These features lead to a stable photocurrent response and reduced electrochemical impedance, indicating improved charge transport and suppressed recombination. As a heterogeneous photocatalyst, complex 1 exhibits exceptional performance in cross-dehydrogenative coupling (CDC) amination reactions between the phenol derivatives and phenothiazine derivatives. These reactions proceeded under mild reaction conditions, using natural light irradiation without the need for strong base and high temperature. The catalyst 1 showed broad applicability, delivering consistently high yields (up to 97%) across more than twenty different substrates. In addition to its high activity, complex 1 exhibits good recyclability and durability, retaining its catalytic activity and structural integrity over at least five cycles. Mechanistic investigations reveal that, under light irradiation, complex 1 efficiently generates superoxide radical anion. These reactive species play a crucial role in activating the reactants to form key radical intermediates, which subsequently couple to afford the desired amination products. Overall, this work demonstrates that integrating a photoactive organic unit into a copper-based framework is an effective strategy for creating durable and efficient photocatalysts, highlighting the promise of TPA-modified copper complexes for sustainable, solar-driven organic transformations.

Dihydropyrrolo[1,2-a]quinoxalines are important structural motifs widely present in natural products and biologically active molecules. Despite various well-developed racemic protocols, the enantioselective synthesis of optically active dihydropyrrolo[1,2-a]quinoxalines via asymmetric catalysis has been relatively less studied. In this work, a borane-catalyzed hydrogenation of pyrrolo[1,2-a]quinoxalines and a chiral phosphoric acid-catalyzed oxidative kinetic resolution of the resulting racemic dihydropyrrolo[1,2-a]quinoxalines via transfer hydrogenation have been successfully integrated into a one-pot process. A variety of optically active dihydropyrroquinoxalines and dihydrobenzoxazinones were obtained simultaneously with high levels of yields and ee's. Notably, this sequential process provides a straightforward method for synthesizing enantioenriched dihydropyrrolo[1,2-a]quinoxaline derivative, which acts as potent agricultural fungicides. The present work combines frustrated Lewis pair-catalyzed hydrogenation and chiral phosphoric acid-catalyzed transfer hydrogenation, providing a facile and efficient method for the simultaneous synthesis of two distinct classes of optically active nitrogen-containing heterocycles.

Visible-light photoredox-catalyzed sulfidation reactions with elemental sulfur have emerged as a mild and attractive strategy to construct sulfur-containing compounds in organic synthetic chemistry. Herein, visible-light-induced pyridylphosphination of alkenes with 4-cyanopyridines, secondary phosphines, and elemental sulfur leading to β-pyridylalkylated phosphine sulfides has been developed. The present photocatalytic pyridylphosphination reaction can incorporate both pyridine and phosphine sulfide structural units into the same molecular framework under mild conditions by using elemental sulfur as sulfur source, in which P=S, C–P, and C–C bonds were successfully constructed in a single operation. A preliminary mechanistic investigation shows that diphenylphosphine sulfide might be the key intermediate and a photocatalytic phosphonyl radical-participated process was involved in this transformation. This visible-light-promoted protocol has the advantages of clean energy source, mild condition, broad substrate scope and good compatibility of functional groups.

Precise control over the active layer morphology is critical for achieving high-performance all-polymer solar cells (all-PSCs). In this study, we introduce a fully “chemically homologous” strategy, in which a series of tailored solid additives, polymer donor, and polymer acceptor are constructed from the same bithiophene imide (BTI) building block. Among them, the B3 additive, which shares an identical side chain with the donor, guides the formation of an optimal fibrillar network morphology with enhanced structural order. This optimized microstructure facilitates efficient exciton dissociation and charge transport, yielding a remarkable power conversion efficiency (PCE) of 18.52%—significantly surpassing those of additive-free (14.54%) and non-homologous reference devices (<17%). Furthermore, this chemically coherent approach promotes ordered molecular packing, simultaneously suppressing molecular disorder and non-radiative energy loss, achieving a low energy loss (E_loss) of 0.509 eV and a high open-circuit voltage (V_OC) of 0.943 V. The B3-processed device also retains outstanding stability, maintaining over 97% of its initial PCE after 1240 h in a nitrogen atmosphere at room temperature. The chemically homologous paradigm demonstrated here provides crucial insights into morphology control and charge transport dynamics in all-polymer blends, offering a promising pathway toward highly efficient and stable organic photovoltaics.

The selective recognition of nitrotoluene isomers remains a considerable challenge in environmental monitoring and chemical sensing. Herein, we report the selective recognition behavior toward nitrotoluene isomers exhibited by a metal-organic pillar (MOP) during its crystallization. A binuclear MOP 1, constructed via coordination-driven self-assembly of a bidentate organic ligand and Zn^II cations, exhibits distinct host–guest behavior toward different nitrotoluene isomers. Single-crystal X-ray diffraction analysis reveals that m-nitrotoluene and p-nitrotoluene form well-defined host-guest inclusion complexes within the cavity of MOP 1 via multiple CH···π and OH···O interactions between the guests and the host. In contrast, o-nitrotoluene undergoes mere mechanical co-crystallization without specific cavity inclusion. Crystallographic studies and DFT calculations establish the recognition order: mNT ≈ pNT > oNT. This study merges MOP synthesis and selective recognition into a single crystallization step, offering an efficient and conceptually novel strategy for the recognition of nitrotoluene isomers.

Polycyclic nucleosides have broad applications in medicinal chemistry and fluorescence-based bioimaging. Therefore, developing efficient synthetic strategies for the rapid construction of novel polycyclic nucleoside frameworks is of significant importance. Herein, we report a novel and practical TEMPO-mediated electrochemical oxidative cyclization/rearrangement, which provides efficient and versatile access to otherwise inaccessible sterically hindered or enantiopure N-alkyl [1,2,4]-triazolone-fused purine nucleosides and related heterocycles with moderate to excellent yields. By combining electrochemical anodic oxidation with aminoxyl catalysis, this protocol enables tandem N–H dehydrogenation, intramolecular cyclization, and 1,2-carbon migration at low potential under mild, metal- and oxidant-free conditions. The synthetic value of this methodology is demonstrated by its broad substrate scope (80 examples, yields up to 99%), excellent functional group tolerance, readily available starting materials (including various N-heteroarenes and primary, secondary, and tertiary alkyl carboxylic acids), and the ability for late-stage functionalization of pharmaceutical compounds and natural products. The protocol has been further applied to the gram-scale preparation of chiral triazolopurinone, maintaining complete stereochemical retention. Detailed mechanistic studies, including radical trapping and crossover experiments, cyclic voltammetry studies, and density functional theory (DFT) calculations, provide evidence supporting a concerted mechanism for C–N bond formation and C–C bond migration. This scalable and sustainable electrochemical rearrangement offers a powerful complementary strategy for the efficient synthesis of structurally diverse 1,2,4-triazolone-fused heterocycles, which may have broad applications in synthetic, biological, and pharmaceutical chemistry.

Planar perovskite solar cells (PSCs) have attracted significant attention in recent years due to their promising applications in renewable energy. However, their practical application is hindered by interface defects, energy level mismatch with the hole transport layer (HTL), and degradation induced by moisture and oxygen. To address these challenges, this study investigates the incorporation of the organic polymer PBDB-T to modify the perovskite/HTL interface. Our findings demonstrate that PBDB-T effectively induces p-type doping at the perovskite surface, leading to an increased work function and improved defect passivation. Furthermore, the synergistic combination of PBDB-T with IT-4F, based on our prior research, creates an internal encapsulation that effectively mitigates moisture and oxygen ingress. As a result, the optimized PSCs achieved a high open-circuit voltage (V_OC) of 1.18 V and a power conversion efficiency (PCE) of 25.14%. Notably, these devices exhibited excellent long-term stability, retaining 84% of their initial efficiency after 4200 h of storage under a nitrogen atmosphere.

The active layer of organic solar cells (OSCs), which processed from volatile and toxic solvents, poses significant challenges for the spontaneous formation of an optimal morphology during the film-forming process. Herein, a non-halogenated solid additive, diphenyl disulfide (DPDS), is employed to enhance the exciton dynamics and photovoltaic performance of OSCs through a two-step aggregation process. Detailed characterization reveals that intermolecular interactions between DPDS and the structural units of L8-BO lead to more pronounced fibrillation of acceptor, a reduced π-π stacking distance, and an extended exciton diffusion length. The ternary OSCs incorporating DPDS additive achieve a power conversion efficiency (PCE) of 19.3% and a fill factor of 80.3%, significantly outperforming the control devices. Notably, the ternary devices processed from both non-halogenated solvent and additive demonstrate no significant loss compared to its halogenated counterparts. This study provides new insights into additive-directed morphology control and offers a promising strategy for the development of high-performance OSCs.

Understanding the solution-state aggregation of conjugated polymers is essential for controlling their film microstructure and improving optoelectronic device performance. However, resolving aggregate structures in donor:acceptor blends remains challenging due to limited contrast and the multicomponent nature of these systems. Here, we selectively deuterate the side chains of poly(3-hexylthiophene) (P3HT) to produce P3HT-D, substantially increasing its neutron scattering length density (SLD). This isotopic modification enables high-contrast small-angle neutron scattering (SANS) analysis of polymer aggregation in solutions of polymer:nonfullerene acceptor (NFA) blends. The enhanced contrast overcomes the deficiencies of conventional X-ray scattering and microscopy, allowing for unambiguous determination of chain conformation and aggregate structure. Photodiodes incorporating P3HT-D show improved responsivity and achieve a high specific detectivity of 5.67 × 10¹³ Jones. These improvements are attributed to refined film morphology, improved miscibility, and reduced nonradiative recombination facilitated by isotopic substitution. Our findings demonstrate that side-chain deuteration provides a dual benefit: (i) enabling precise structural characterization and (ii) tuning intermolecular interactions to improve device performance. This study establishes side-chain deuteration as a versatile strategy for structural analysis, microstructure engineering, and performance optimization in conjugated polymer–based organic photodiodes.

The hydrosilylation of internal alkynes is an important protocol for the synthesis of trisubstitued alkenyl silanes, which are very useful building blocks in synthetic chemistry and materials science. However, the hydrosilylation of inactivated internal diaryl alkynes with (aryl)(vinyl)silanes or diphenylsilane faces challenges of the lack of active catalyst and difficulty in controlling stereoselectivity. Herein, the bridged pincer homodinuclear rare-earth metal complexes [μ-η²-{κ³_OCO-1-(2-C₄H₇OCH₂)-3-(Ph₂P(O)CH)C₈H₄N}RE(CH₂SiMe₃)]₂ (RE = Lu(1a), Yb(1b), Er(1c), Y(1d), Dy(1e), Gd(1f)), [μ-η²-{κ³_OCO-1-MeOCH₂CH₂-3-(Ph₂P(O)CH)C₈H₄N}RE(CH₂SiMe₃)]₂ (RE = Lu(2a), Y(2b)) and [μ-η²-{κ³_OCN-1-(2-C₅H₄N)-3-(Ph₂P(O)CH)C₈H₄N}RE(CH₂SiMe₃)]₂ (RE = Lu(3a), Yb(3b), Er(3c)) were synthesized. Meanwhile, the pincer mononuclear complexes κ³_OCO-[1-(2-C₄H₇OCH₂)-3-(Ph₂P(O)CH₂)C₈H₄N]Lu(CH₂SiMe₃)₂ (1a'), and κ³_OCO-[1-MeOCH₂CH₂-3- (Ph₂P(O)CH₂)C₈H₄N]Lu(CH₂SiMe₃)₂ (2a') were prepared for comparison of their catalytic activities with the homodinuclear complexes. These homodinuclear complexes displayed high catalytic activity in the hydrosilylation of inactivated internal diaryl alkynes with RSiH₃ (R = C₆H₅-, 4-CH₃C₆H₄-, C₈H₁₇-, C₆H₁₃-), (aryl)(vinyl)silanes and diphenylsilane, affording the vinylsilane products in moderate to high yields with excellent stereoselectivity. Among the complexes surveyed, the homodinuclear complex 1d exhibited the highest activity. Moreover, the bis-hydrosilylation of two different internal alkynes with RSiH₃ was also developed. Control experiments evidence supports that the synergistic interaction between the bimetallic centers in these complexes played a crucial role in their high efficiency demonstrated in the reaction.

Two-dimensional (2D) covalent organic frameworks (COFs) are known for their semiconducting features, which stem from the extended conjugated backbones within their stacked layers. These attributes render 2D COFs highly suitable for photocatalysis, with electron transfer facilitated by their conjugated lattices. A common strategy to enhance photocatalytic performance has been to design topologies that elevate π-column density using geometrically appropriate building blocks. However, this often leads to hydrophobic microporous channels, impeding efficient mass transfer. Herein, we introduce a novel methodology by employing six-connected HFPTP, three-connected TPB, and V-shaped two-connected m-TPDA as building blocks. By adjusting the TPB to m-TPDA molar ratio, we have successfully integrated regular defects into the kgd lattice, resulting in modified kgd COFs with rhombic and hexagonal star-shaped pores. This design diverges from the conventional kgd topology, which typically yields small micropores, to one that incorporates mesopores through the strategic placement of defects within the skeletons. The resulting defect-mediated 2D HP-COF, with its optimized aperture ratio and energy levels, along with enhanced mass transfer, demonstrates a significantly improved photocatalytic hydrogen peroxide production rate of 7433 μmol·g⁻¹·h⁻¹. This performance surpasses that of non-defect-based counterparts, underscoring the pivotal role of structural defect engineering in advancing the photocatalytic efficiency.

PEDOT:PSS has been extensively employed as a hole transport layer in solution-processed organic solar cells. However, its imperfect interfacial contact and energy level mismatch with the active layer restrict charge extraction and limit device performance. Herein, we demonstrate a novel interfacial engineering strategy by depositing an ultrathin D18-Cl interlayer atop the conventional PEDOT:PSS hole transport layer. This strategy significantly improves the contact between the hole transport layer and the active layer, thereby forming a more favorable energy level alignment, thus enhancing charge extraction and reducing recombination losses. As a result, the optimized devices exhibit improved charge extraction, suppressed dark current density, and reduced charge recombination. Therefore, the binary OSCs based on PM6:Y6, PM6:BTP-eC9, and PM6:L8-BO treated with D18-Cl, achieved power conversion efficiencies of 18.93%, 19.35%, and 19.92%, respectively. In summary, this study provides a practical approach to boosting OSC performance via rational interfacial design, paving the way for high-efficiency photovoltaic technologies.

The importance of Si-stereogenic silanes has been recognized in many fields of chemical science. Consequently, numerous catalytic enantioselective methods for their synthesis have been developed. Despite these advances, such methods have traditionally relied on transition-metal catalysts, predominantly rhodium and palladium. Recently, Brønsted acid catalysts have emerged as powerful alternatives to transition-metal catalysts. In particular, imidodiphosphorimidate (IDPi) and chiral phosphoric acid (CPA) catalysts have enabled access to structurally diverse Si-stereogenic silanes, including silyl ethers, silacycles, and disiloxanes, that were not previously attainable. In this review, we describe the recent advances made in Brønsted acid catalysis for the synthesis of Si-stereogenic silanes. We also discuss the relevant background and reaction mechanisms. We hope that this review will suggest future research directions in this emerging area.

The fast increase in atmospheric carbon dioxide (CO₂) concentration has become a pressing issue that requires immediate attention to mitigate the significant global warming and the associated environmental crisis. Although the ongoing development of renewable technologies provides long-term solutions to reduce CO₂ emissions, the current global aim to cut emissions and reach near-zero emissions by 2050 requires more effective complementary methods to achieve the goals. Sorbent-based CO₂ capture offers a promising approach to realize massive carbon capture and storage due to its low cost. Central to the advantages of this method are porous solids, and an efficient capture process requires the materials to have high CO₂ capacity, fast kinetics, good selectivity, and long-term stability under operating conditions. Guided by reticular chemistry, which enables the linking of molecular building blocks into crystalline frameworks through strong bonds, covalent organic frameworks (COFs) emerge as a new class of crystalline functional polymers and have demonstrated great potential as efficient CO₂ adsorbents due to their high porosity, tailor-made pore environment, and excellent stability. The CO₂ uptake capacity of COF-based sorbent exhibits a high value up to 6 mmol·g^–1 at 273 K and 1 bar. Considering the impressive progress in this field, a timely review summarizing the past structural design strategies of COFs for CO₂ sorption and revealing the underlying structure-function relationship can pave the way for developing the next-generation COF-based sorbents for practical CO₂ capture. This review provides the fundamental design principles of COFs and summarizes the recent de novo and post-synthetic modification methods for designing suitable COFs toward CO₂ capture. The important role of the building units, the linkages, and the topologies of COFs that elucidate the basic structural properties of COFs during the formation of the crystalline frameworks and the CO₂ capture process is highlighted. Finally, the challenges and possible future development of this field are discussed.

In 2009, Yaghi and co-workers reported the first experimental study of CO₂ adsorption in COFs, opening the following works on applying COFs to CO₂ adsorption and advancing the development of this field over the past two decades. In 2015, Jiang and co-workers developed several post-synthetic modification methods to modify COFs toward CO₂ adsorption. The pore environment of COFs could be modified by the famous click reactions and the well-developed ring-opening reaction, thus enhancing the CO₂ capture performance of these COFs. In addition to post-synthetic modification methods, Loh (2018), Lotsch (2019), and their co-workers constructed several 2D COFs with unreacted functional groups for CO₂ adsorption through direct synthesis. Besides 2D COFs, Wang, Fang, and co-workers designed a series of 3D COFs and applied them to CO₂ adsorption between 2016 and 2021. In 2023, Zhao and co-workers reported a post-synthetic modification method to modify the pore properties of COFs. They doped the COFs with metal salts and achieved an impressive enhancement of their CO₂ adsorption performance. In 2024, Yaghi and co-workers reached a milestone by introducing the polyamine species into COFs. These new COF-based CO₂ adsorbents could achieve direct CO₂ capture from the air with exceptional uptake capacity, high cyclic stability, and fast kinetics.

Organic photovoltaic (OPV) cells are a key part of next-generation flexible optoelectronic technologies, offering lightweight, environmentally friendly, and printable energy solutions based on renewable resources. With the development of new donor–acceptor materials and advances in device design, the power conversion efficiency of OPV cells has now surpassed 21% (the highest certified value of 20.80%). However, optimizing these complex, multi-component active layers using traditional experimental approaches is slow and inefficient due to the enormous chemical space and the need to balance both morphological and electronic properties. In this context, machine learning (ML) has emerged as a powerful tool for handling complex data and modeling nonlinear relationships in OPV research. This review provides a concise overview of recent ML applications in the OPV field. We focus on its role in accelerating material discovery by rapidly screening large material libraries and identifying promising donor–acceptor combinations with suitable energy level alignment. We also highlight ML-based performance prediction, which enables the estimation of device efficiency and stability before synthesis and fabrication. In addition, the integration of ML with automated experimental platforms is discussed, enabling high-throughput optimization of processing conditions and supporting future large-scale production. Although challenges such as limited data and model interpretability remain, the continued integration of machine learning with advanced experimental techniques is expected to significantly accelerate OPV development and promote the transition of organic photovoltaics from laboratory research to practical applications.

Transition-metal-catalyzed carbene transfer reactions have emerged as a robust and versatile strategy in organic synthesis. Conventional carbene transfer processes primarily encompass C–H bond insertion, cyclopropanation, and ylide formation, which have found extensive applications both in academic research and industrial settings. A prominent example includes the Rh(II)-catalyzed intramolecular N–H insertion employed in the synthesis of β-lactam antibiotics such as thienamycin, as well as asymmetric cyclopropanation utilized in the production of chrysanthemate-based insecticides. Over the past decade, a novel class of transition-metal-catalyzed transformations involving carbene precursors has gained significant attention. In these reactions, diazo compounds—or their precursors such as N-tosylhydrazones—serve as cross-coupling partners for the construction of C–C single or C=C double bonds. The transformations developed thus far in this field are summarized in the accompanying figure. These processes typically proceed via metal–carbene intermediates followed by migratory insertion steps, enabling efficient bond formation under either redox-neutral or oxidative conditions. The broad compatibility of various carbene precursors and coupling partners has greatly enhanced the synthetic utility of this approach. This carbene-based coupling strategy has demonstrated wide applicability, with numerous transition metals—including Pd, Cu, Rh, Ni, Co, and Ir—proving effective as catalysts. Moreover, the substrate scope has expanded beyond diazo compounds to include other carbene sources, and diverse cascade processes have been designed based on carbene migratory insertion. In addition, this methodology has been integrated with C–H functionalization, fluorine chemistry, and more recently, metal-hydride-mediated transformations. Its utility extends from the synthesis of complex molecules to the development of functional polymeric materials. Concurrently, asymmetric versions of carbene cross-coupling reactions are being actively explored, although considerable challenges remain in this area. This review summarizes the historical development and recent advances in transition-metal-catalyzed carbene transfer reactions, with a focus on emerging coupling strategies and their synthetic applications.