Song Q, Ukani R, Dev VM
… +13 more, Kim HK, Shin J, Seo J, Stamper C, Laorenza DW, McGillicuddy RD, Calvin JJ, Moon Y, Thai C, Braun JD, Yu D, Chen G, Mason JA
J Am Chem Soc
· 2026 Jun · PMID 42347562
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The development of strategies to modulate the thermal conductivity of a solid in response to an external stimulus is critical to the creation of high-performance thermal regulators, thermal switches, and thermal diodes─d...The development of strategies to modulate the thermal conductivity of a solid in response to an external stimulus is critical to the creation of high-performance thermal regulators, thermal switches, and thermal diodes─devices which would be enabling for a wide range of emerging technologies. Here, we report a new mechanism for achieving switchable solid-state thermal conductivity through a first-order spin-crossover phase transition. Specifically, we show that single crystals of the molecular spin-crossover complex Fe(HB(tz)) [HB(tz) = hydrotris(1,2,4-triazol-1-yl)borate] exhibit a large drop in thermal conductivity, more than 4-fold, across an electronic spin transition. This thermal conductivity change is highly reversible and can be attributed to lower group velocities of heat-carrying phonons and increased phonon scattering in the high-spin phase of the compound as a result of weaker metal-ligand bonds. We further demonstrate the generalizability of this phenomenon by showing a similarly large change in thermal conductivity for another Fe(II) spin-crossover material with a different coordination environment and transition temperature. Owing to the large structural and chemical diversity of spin-crossover materials and the rich variety of stimuli that can induce electronic spin transitions, these results establish a powerful approach to manipulating thermal transport within solid materials.
J Am Chem Soc
· 2026 Jun · PMID 42345574
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Although CuO(111) is thermodynamically favorable for CO electroreduction, ethylene production is limited by insufficient Cu stabilization, leading to modest selectivity and durability. Herein, we report an interfacial en...Although CuO(111) is thermodynamically favorable for CO electroreduction, ethylene production is limited by insufficient Cu stabilization, leading to modest selectivity and durability. Herein, we report an interfacial engineering strategy to construct nanoscale-coupled CuO-ZrO heterointerfaces that stabilize Cu and promote C-C coupling. Using a zirconium-based metal-organic framework as a confined-conversion template, uniformly dispersed CuO(111)-ZrO interfaces are generated within a conductive porous carbon matrix (CuZr@C). CuZr@C delivers FE = 72.1% at = 39.0 mA cm (-1.3 V vs RHE) in an H cell with >70% retention after 120 h and = 101.6 mA cm in a flow cell. Operando X-ray absorption spectroscopy and Raman confirm Cu stabilization and high local CO coverage at the heterointerface. Density functional theory reveals a reduced free-energy barrier of 0.68 eV for the rate-determining *OCCO → *OCCHO step, establishing CuO(111)-based oxide heterointerfaces as effective platforms for durable and selective CORR to multicarbon products.
Wang Y, Dhungana BR, Trevino R
… +13 more, Sun Y, Yang W, Zhai H, Nand S, Nguyen VTB, Geng H, Sanchez JA, Huang C, Elerian R, He M, Cheng M, Larionov OV, Jin S
J Am Chem Soc
· 2026 Jun · PMID 42345279
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Regioselective introduction of functional groups at distal positions of carbonyl compounds remains a significant challenge, often necessitating inefficient stepwise routes to access synthetically and medicinally importan...Regioselective introduction of functional groups at distal positions of carbonyl compounds remains a significant challenge, often necessitating inefficient stepwise routes to access synthetically and medicinally important targets such as 1,6-aminocarbonyls. Direct radical α-functionalization of carbonyls can unlock broad scope strategies for position-specific installation of diverse functionalities and can address the inherent limitations of enolate-based approaches. However, the development of radical α-functionalization has remained underexplored due to the scarcity of catalytic systems capable of efficiently promoting both the direct generation of α-carbonyl radicals and the regioselective construction of distally functionalized frameworks. We report herein the development of a tricomponent cobalt(salen)-catalyzed α-alkylation of carbonyl compounds, providing a direct approach to 1,6-aminocarbonyl frameworks from diverse unactivated carbonyls and aromatic amines. The reaction proceeds through a cobalt(salen)-catalyzed sequence involving polar-radical crossover (PRC), which enables direct formation of α-carbonyl radicals, and radical-polar crossover (RPC), which mediates regiospecific installation of the distal amino group. The method tolerates a wide range of carbonyl substrates, including α-substituted aldehydes that are typically prone to deleterious hydrogen atom transfer from the reactive carbonyl group. Mechanistic studies reveal the roles of cobalt(salen) O- and C-enolates in the PRC step and the involvement of α-carbonyl radicals in enabling the RPC process.
Guo R, Li F, Wang L
… +4 more, Ba M, Guo Z, He W, Li A
J Am Chem Soc
· 2026 Jun · PMID 42345253
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Scholarisine A () represents a structurally distinct and synthetically intriguing subfamily of the echitamine/akuammiline-type alkaloids. Inspired by its postulated biogenetic logic, we developed a radical cyclization st...Scholarisine A () represents a structurally distinct and synthetically intriguing subfamily of the echitamine/akuammiline-type alkaloids. Inspired by its postulated biogenetic logic, we developed a radical cyclization strategy that retains the key bond-forming site while replacing the aldol reaction. This reaction-altering biomimetic strategy, combined with expeditious preparation of a tetracyclic precursor, enabled a 13-step, scalable synthesis of . Moreover, facile access to its congeners, scholarisines I, T, and W (-), was achieved. Compound impairs lysosomal degradative capacity and thus inhibits late-stage autophagy in cancer cells.
Wardzala JJ, Kim Y, Khurana R
… +4 more, Mandal M, Delferro M, Liu C, Gagliardi L
J Am Chem Soc
· 2026 Jun · PMID 42345126
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Methane C-H activation at transition-metal sites often involves electronic structures that challenge conventional single-reference electronic structure descriptions. Although Kohn-Sham density functional theory (DFT) is...Methane C-H activation at transition-metal sites often involves electronic structures that challenge conventional single-reference electronic structure descriptions. Although Kohn-Sham density functional theory (DFT) is widely used to study catalytic trends, its reliability for reactions involving strongly correlated species remains uncertain. Here we present a systematic multireference investigation of methane activation at metal-organic framework (MOF) node catalysts across the 3 transition-metal series. We introduce an automated workflow for active space selection to enable consistent application of multireference methods, including multiconfiguration pair-density functional theory and -electron valence state perturbation theory, to these catalytic systems. These calculations show substantial static correlation in the C-H activation reaction step and predict activation barriers that differ from DFT by 30-70 kJ mol, with DFT often qualitatively disagreeing in barrier height trends across transition metals. Analysis of multireference wave functions shows that reactivity is governed by the electronic structure of the M-O moiety along a continuum from metal-oxo to oxyl radical and O biradical character. Increased oxygen-centered spin density and weakened M-O bonding are identified as descriptors of catalytic activity which correlate with lower activation barriers.
J Am Chem Soc
· 2026 Jun · PMID 42345084
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Ternary iron spinel oxides are promising materials for photo(electro)catalytic applications. However, like other first-row transition metal oxides, these materials have a propensity to form localized photoexcited states...Ternary iron spinel oxides are promising materials for photo(electro)catalytic applications. However, like other first-row transition metal oxides, these materials have a propensity to form localized photoexcited states known as polarons that may impact their performance. In this work, we explicitly link computed electronic and vibrational structures to experimental optical dielectric and resonance Raman spectra to establish the optical polaronic properties of three different ternary iron spinel oxides: CoFeO, NiFeO and FeNiO. Ternary iron spinel oxides are known to crystallize with a range of different distributions of cations among tetrahedral and octahedral sites. Here, we correlate heterogeneous broadening observed in resonance Raman spectra and sub-band gap charge transfer transitions observed in optical dielectric spectra to cation inversion. We use DFT computations to demonstrate the sensitivity of charge transfer transitions to changes in cation inversion in CoFeO and NiFeO. Experimentally, charge transfer transitions at the band-edge that arise from cation inversion exhibit strong phonon coupling in all three ternary iron spinel oxides, which is indicative of the formation of localized photoexcited states. We establish that, by changing the composition of the ternary iron spinel, the phonon mode that exhibits the strongest coupling to the band-edge absorption also changes, suggesting that the structure of photogenerated polarons in ternary iron spinel oxides can be controlled by tuning their composition. With a fundamental understanding of how composition influences the localization of photogenerated charge carriers, there are opportunities for rational material engineering to harness these carriers in photocatalytic applications.
Zhong Z, Zhou H, Huang Z
… +4 more, Zhang Y, Wang J, Liu H, Li X
J Am Chem Soc
· 2026 Jun · PMID 42343654
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-glycosylation is one of the most ubiquitous protein post-translational modifications with both high structural diversity and critical functions in broad molecular biological processes. The effect of -glycans on high-mob...-glycosylation is one of the most ubiquitous protein post-translational modifications with both high structural diversity and critical functions in broad molecular biological processes. The effect of -glycans on high-mobility group box 1 (HMGB1) has not been clearly elucidated. Chemical protein synthesis, in combination with enzymatic transglycosylation, provides a robust approach to obtain homogeneous -glycoproteins with well-defined glycan structures on designated sites, therefore allowing the investigation of the biological effects of -glycosylation on site- and structure-specific levels. In this work, the synthetic route toward full-length fully reduced HMBG1 was established, which was adopted to the syntheses of -glycosylated HMBG1 variants bearing sialylated biantennary -glycans. The synthetic -glycoproteins were employed to investigate the effects of -glycosylation on the interactions of HMGB1 with receptors RAGE, as well as the HMGB1-stimulated cell migration and CXCL12 secretion. The potential effect of -glycans on the HMGB1/RAGE interaction was investigated via molecular dynamics simulations.
Gao Y, Li H, Wang T
… +5 more, Yang X, Sun S, Long Y, He J, Jiang JH
J Am Chem Soc
· 2026 Jun · PMID 42343537
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Cells employ lysosomal degradation to eliminate extracellular and membrane proteins, which is a process that can be exploited for therapeutic purposes. Current lysosome-targeting chimeras (LYTACs) that hijack endogenous...Cells employ lysosomal degradation to eliminate extracellular and membrane proteins, which is a process that can be exploited for therapeutic purposes. Current lysosome-targeting chimeras (LYTACs) that hijack endogenous lysosome-associated receptors (LARs) to degrade pathogenic proteins are constrained by their reliance on endogenous receptor trafficking. Here we introduce synthetic chimeric antigen lysosome-associated receptors (CALARs) that reprogram cells to effectively sort extracellular proteins to lysosomes, operating independently of native ligand competition. Encoded within circular RNA, CALARs enable sustained suppression of immune checkpoints and growth factor receptors for over 1 week. This prolonged suppression enhances immune activation and substantially reduces the tumor burden in vivo. This study introduces a modular, genetically encodable platform for modulating protein expression and advancing cell-based therapeutics.
Richter N, Regni G, Baldinelli L
… +3 more, Leutzsch M, Bistoni G, Fürstner A
J Am Chem Soc
· 2026 Jun · PMID 42342599
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A catalyst generated in situ from a bench-stable nickel stilbene complex and the axially chiral VAPOL-derived phosphoramidite ligand is capable of affecting the asymmetric reductive coupling of aldehydes with 6,6-difluo...A catalyst generated in situ from a bench-stable nickel stilbene complex and the axially chiral VAPOL-derived phosphoramidite ligand is capable of affecting the asymmetric reductive coupling of aldehydes with 6,6-difluorosorbamide or 6,6,6-trifluorosorbamide derivatives and related fluorinated compounds using EtB as the promoter. The ligand controls the regioselective course and imposes excellent levels of asymmetric induction onto the reaction that generates di(tri)fluoromethylated stereogenic centers concomitant with an adjacent secondary alcohol from the prochiral substrates. Because the resulting structural motif constitutes a fluorinated bioisostere of a common type of -configured deoxypropionate unit, the new method potentially qualifies for a "fluoride scan" of numerous bioactive (natural) products. A mechanistic study revealed that one cannot extrapolate from the nickel speciation in solution and/or accessible by crystallization to the actual site of the polarized 1,3-diene at which the reductive C-C-bond formation will take place. Moreover, the only detectable complex derived from the Ni(0) precatalyst, , and a trifluoromethylated sorbamide is off the catalytic cycle; it serves as a "reservoir", as clearly manifested in the negative nonlinear effect ((-)-NLE) between the optical purity of and that of the resulting product. A DFT study allowed these observations to be rationalized and a mechanism of the reaction to be proposed.
Qi X, Zhang B, He Z
… +3 more, Chen W, Li Q, Yan Q
J Am Chem Soc
· 2026 Jun · PMID 42342560
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Black phosphorus, featuring a distinctive layered structure and exceptional properties, has driven the exploration of scalable fabrication strategies, among which solvothermal synthesis is pursued for its mild conditions...Black phosphorus, featuring a distinctive layered structure and exceptional properties, has driven the exploration of scalable fabrication strategies, among which solvothermal synthesis is pursued for its mild conditions. However, the true identity of the resulting products remains obscured by persistent misinterpretations. In this work, we systematically revisit the purported solvothermal "black phosphorus", particularly that synthesized in ethylenediamine. In contrast to authentic black phosphorus, this material exhibits intrinsic discrepancies that challenge its conventional assignment as an elemental allotrope, thereby clarifying the origins of such confusion. Employing continuous rotation electron diffraction, we have determined the crystallographic parameters of its average structure, revealing a quasi-one-dimensional architecture with significant disorder. Multimodal characterizations redefine this material as a salt-like assembly of ethylenediammonium polyphosphides. Further structural rationale is guided by the Baudler rules of phosphorus catenation and generalized to a broader series of organic ammonium polyphosphide hybrids that feature an invariant backbone. While acknowledging the reported functional potential of these materials, this study prompts a fundamental reappraisal of the structure-property relationship, establishing an interpretive framework for the rational design of phosphorus-based materials.
Zhou Y, Song Y, Yu X
… +3 more, Zhou S, Pei W, Zhao J
J Am Chem Soc
· 2026 Jun · PMID 42342435
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Controlling the spin state of single molecules is central to the next-generation molecular electronics and spintronic architectures. Using first-principles computational methods, we systematically investigate the geometr...Controlling the spin state of single molecules is central to the next-generation molecular electronics and spintronic architectures. Using first-principles computational methods, we systematically investigate the geometrical, electronic structures, magnetic properties, and transport behaviors of the sandwich-like [Cp-(cyclo-)-Cp] ( = Sb, Bi; M = V, Ta, Nb) nanoclusters (NCs), which feature a unique "metal-ring-metal" topology. We demonstrate that mechanical perturbations─specifically the vertical translation and in-plane rotation of the central ring─ effectively modulate the localized coordination field to enable robust, reversible high-spin to low-spin (HS ↔ LS). Moreover, in specific oxidation states, these distinct spin states are coupled with unique magnetic correlations, where the HS state exhibits ferromagnetic (FM) alignment and the LS state manifests antiferromagnetic (AFM) coupling. Crucially, the rotational dynamics of the central ring realize a temperature-dependent, conformationally switchable magnetic phase, while electronic charge modulation provides a highly sensitive, orthogonal axis for gating these magnetic characteristics. These combined mechanical and electrical degrees of freedom yield highly distinctive magnetic signatures and spin-polarized electronic transport profiles. By mapping out specific candidate molecules, highlighting the antimony-based [Cp-V(cyclo-Sb)V-Cp] NCs framework as an exceptional candidate for multimode mechanical control, our findings deliver a rigorous, structure-driven blueprint for molecular spin regulation, positioning this class of nanoclusters as highly promising platforms for single-molecule memory, nanoscale spin valves, and molecular spintronic applications.
Guo GC, Ma L, Guo S
… +3 more, Zhang L, Lu TB, Zhang ZM
J Am Chem Soc
· 2026 Jun · PMID 42342361
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The development of photosensitizing materials synergizing broad-spectrum harvesting with long-lived excited states is pivotal for advancing artificial photosynthesis. Herein, we propose a precoordination-induced coassemb...The development of photosensitizing materials synergizing broad-spectrum harvesting with long-lived excited states is pivotal for advancing artificial photosynthesis. Herein, we propose a precoordination-induced coassembly strategy to integrate complementary chromophores into unsaturated Cu-MOFs (Cu-0 - Cu-123), enabling synergistic tuning of their photon absorption channels and excited states. The cosensitized Cu-123 exhibits panchromatic absorption across 200-700 nm and a prolonged excited-state lifetime of 10.2 μs via a "ping-pong" cascade energy transfer, which is over 200-fold longer than that in the pristine framework of Cu-0 (<0.05 μs). Remarkably, it achieves an outstanding yield (76.4%) in artemisinin photosynthesis and demonstrates exceptional versatility across a diverse range of organic transformations (>10 distinct reactions). Gram-scale synthesis under sunlight achieved via the construction of a continuous-flow photoreactor indicates its potential for scalable solar energy conversion. This work not only presents highly efficient photocatalysts but also establishes a general method for constructing porous photosynthesis systems with tailored photophysical properties for solar-to-chemical conversion.
Tan Q, Zhao Y, Zhang Y
… +5 more, Chen H, Xu Z, Pan Z, El-Khouly ME, Yuan Y
J Am Chem Soc
· 2026 Jun · PMID 42341263
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Idiopathic pulmonary fibrosis (IPF) is sustained by a self-amplifying pathological circuit involving senescence-associated epithelial injury and fibroblast activation, which together drive persistent inflammatory signali...Idiopathic pulmonary fibrosis (IPF) is sustained by a self-amplifying pathological circuit involving senescence-associated epithelial injury and fibroblast activation, which together drive persistent inflammatory signaling, excessive extracellular matrix deposition, and progressive loss of lung function. Although proteolysis-targeting chimeras (PROTACs) offer a powerful approach to eliminate disease-driving proteins, their application in fibrotic lung disease remains limited by inefficient pulmonary delivery, poor lesion retention, and insufficient intervention in multicellular profibrotic networks. Herein, we develop an inhalable enzyme-activated polymeric PROTAC nanococktail that enables concurrent degradation of two key profibrotic signaling regulators in fibrotic lungs. The nanococktail consists of GAL@SD and FAP@BD, two disease-microenvironment-responsive nanoparticles carrying distinct PROTAC cargos. GAL@SD responds to elevated senescence-associated β-galactosidase activity in fibrotic lungs and releases a stimulator of interferon genes (STING)-degrading PROTACs to suppress senescence-associated inflammatory signaling linked to impaired alveolar epithelial repair. FAP@BD is activated by fibroblast activation protein-α enriched in activated fibroblast-dominated fibrotic regions, delivering a bromodomain-containing protein 4 (BRD4)-degrading PROTAC to inhibit myofibroblast activation and extracellular matrix production. After inhalation, both nanoparticles exhibit efficient mucus penetration, improved pulmonary retention, and preferential accumulation in fibrotic lesions, enabling localized degradation of STING and BRD4. In a bleomycin-induced mouse model of pulmonary fibrosis, the combined PROTAC nanococktail achieves superior therapeutic efficacy compared with either single PROTAC nanoparticle, as demonstrated by restored lung architecture, improved respiratory function, reduced collagen deposition, and reversal of fibrosis-associated transcriptional programs. These results demonstrate an inhaled dual-PROTAC nanotherapeutic strategy for simultaneously attenuating epithelial senescence-associated inflammation and fibroblast-driven matrix remodeling.
Cai DQ, Wu H, Yang JL
… +3 more, Zhang T, Xue T, Fan HJ
J Am Chem Soc
· 2026 Jun · PMID 42341232
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Serious self-discharge due to side reactions and the shuttle effect has been formidable limits for liquid zinc-iodine batteries. Hydrogel electrolytes can reduce self-discharge in certain degree and induce new properties...Serious self-discharge due to side reactions and the shuttle effect has been formidable limits for liquid zinc-iodine batteries. Hydrogel electrolytes can reduce self-discharge in certain degree and induce new properties of biocompatibility and mechanical flexibility. However, without a proper interface, chemical welding, most hydrogel ZIBs suffer from poor interfacial robustness, particularly under deformation, compromising the battery cycle life. To mitigate this issue, we deploy an in situ integration strategy to construct chemo-mechanical dynamically adaptive interfaces to enable high-iodine-loading hydrogel batteries. On the anode side, the interfacial polycatecholamine accommodates surface evolution via robust adhesion, induces a stable hybrid interphase, and functions as an ion sieve. Simultaneously, the hydrogel permeates the dry-processed cathode, forming a low-tortuosity ion transport pathway that adapts to volume fluctuations and chemically immobilizes polyiodides. This dual-role strategy enables low self-discharge (∼20% loss after 200 h) and unlocks the potential for high areal capacity (∼12.5 mAh cm) in thick cathodes. At an areal capacity of ∼5 mAh cm (>40 mg cm iodine loading), the hydrogel battery can sustain over 2200 cycles with a negligible capacity decay of 0.0063% per cycle.
Bowers NK, Gonzalez BI, Müller N
… +4 more, Ngo V, Teoh YS, Claggett TA, Krische MJ
J Am Chem Soc
· 2026 Jun · PMID 42341225
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Metal-catalyzed -heteroaryl C-H functionalizations to form quaternary heterobenzylic carbon centers are described. Exposure of 1,1-disubstituted allenes to the ruthenium catalyst derived from RuHCl(CO)(PPh) and Cy-BIPHEP...Metal-catalyzed -heteroaryl C-H functionalizations to form quaternary heterobenzylic carbon centers are described. Exposure of 1,1-disubstituted allenes to the ruthenium catalyst derived from RuHCl(CO)(PPh) and Cy-BIPHEP results in generation of allylruthenium nucleophiles that engage in azine or azole C═N addition to deliver transient dearomatized homoallylic amidoruthenium complexes, which upon β-hydride elimination release products bearing quaternary -heterobenzylic carbon centers with regeneration of the starting ruthenium hydride. The dearomative addition-β-hydride elimination pathway is corroborated by deuterium-labeling experiments and interception of the dearomatized amidoruthenium intermediate through its protonolytic cleavage by 2-propanol and conversion to the methanesulfonamide. Comparison of RuCl(η-CH)(CO)(Cy-BIPHEP) vs RuCl(η-CH)(CO)(BIPHEP), including single crystal X-ray diffraction and IR data, provides insight into the superior performance of the Cy-BIPHEP-modified catalyst.
Chen H, Zhao T, Li W
… +18 more, He L, Guo J, Yao ZF, Ma C, Fan Y, Jiang B, Zhang L, Zhang H, Liu S, Zhang Z, Sun L, Yang L, Brozek CK, Zheng YQ, Li J, Chen T, Sun J, Dou JH
J Am Chem Soc
· 2026 Jun · PMID 42341214
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Conductive metal-organic frameworks (c-MOFs) are promising functional materials, yet their atomic-level clarity remains obscured by the limited size of available single crystals (typically <10 μm). We demonstrate that th...Conductive metal-organic frameworks (c-MOFs) are promising functional materials, yet their atomic-level clarity remains obscured by the limited size of available single crystals (typically <10 μm). We demonstrate that the kinetic mismatch between redox-coordination processes and crystal growth is the underlying obstacle, and propose a general strategy to reduce this mismatch by balancing the ligand acid-base equilibrium to control the redox-coordination kinetics. This kinetic aligning strategy enables the growth of single crystals up to over 1 mm in seven c-MOFs, and reveals three new crystal structures with distinct electronic properties. Single-crystal devices demonstrate record-high intrinsic electron-proton dual conductivity among porous MOFs. This work establishes both a fundamental framework and a practical strategy for growing c-MOF single crystals and designing materials that integrate electronic and protonic transport.
Dong H, Chen N, He X
… +3 more, Cui W, Lei A, Yi H
J Am Chem Soc
· 2026 Jun · PMID 42340870
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Sulfur anions have emerged as promising photosensitizers for light-driven single-electron transfer (SET) chemistry. Established mechanistic pictures typically invoke substrate preassociation, either through electron dono...Sulfur anions have emerged as promising photosensitizers for light-driven single-electron transfer (SET) chemistry. Established mechanistic pictures typically invoke substrate preassociation, either through electron donor-acceptor (EDA) complexation or via covalent adduct formation. Recent reports, however, describe sulfur-anion systems that operate efficiently in the apparent absence of these canonical pathways, highlighting an unresolved role for the intrinsic excited-state properties of sulfur anions. Here, we map the photochemical cycle of a representative sulfur-anion, , photosensitizer by combining optical and magnetic spectroscopies. We show that its absorption originates from intramolecular charge-transfer (ICT) transitions and can be shifted into the visible region through π-system extension. Time-resolved measurements indicate that static and dynamic electron-transfer pathways can coexist, with the dominant route depending on substrate identity. In particular, polycyclic aromatic substrates favor static quenching, correlating with markedly faster reactions. In the investigation of light-induced reductive dehalogenation functionalization reactions, demonstrated higher catalytic efficiency, in which TON up to 248 with 0.4 mol % loading. The data are consistent with non-covalent pre-association that leaves the sensitizer's intrinsic energy-level landscape largely unchanged, raising the possibility of anti-Kasha reactivity. Together, these findings provide spectroscopic constraints on bimolecular charge-transfer mechanisms of sulfur-anion photosensitizers and offer design principles for more efficient photocatalytic SET processes.
J Am Chem Soc
· 2026 Jun · PMID 42340860
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The selective chemical modification of lysine residues beyond its ε-amino group remains a long-standing challenge in peptide synthesis due to the conformational flexibility of the residue, the nucleophilicity of the amin...The selective chemical modification of lysine residues beyond its ε-amino group remains a long-standing challenge in peptide synthesis due to the conformational flexibility of the residue, the nucleophilicity of the amine group, and the inert C(sp)-H bonds of the aliphatic side chain. Herein we report a photoredox-catalyzed reaction for site-selective C(sp)-H functionalization of lysine and other primary amine residues through α-amino radical intermediates generated from trifluoroacetamide protecting groups. This transformation proceeds under mild conditions and exhibits broad tolerance to residue identity and alkene coupling partners. The technology is compatible with standard Fmoc-solid phase peptide synthesis and direct on-resin modification. The method facilitates both intermolecular alkylation and intramolecular macrocyclization, providing access to a diverse array of unnatural amino acid motifs and peptide architectures. Collectively, this work establishes redox-active amide protecting groups as versatile handles for radical generation in complex molecular settings and expands the toolbox for late-stage peptide diversification.
J Am Chem Soc
· 2026 Jun · PMID 42340360
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The borderline rotational barrier of class 2 atropisomeric quinones makes their enantioselective synthesis challenging. Herein we report the first catalytic atroposelective formal C(sp)-H methylation and alkenylation of...The borderline rotational barrier of class 2 atropisomeric quinones makes their enantioselective synthesis challenging. Herein we report the first catalytic atroposelective formal C(sp)-H methylation and alkenylation of atropisomerically labile 2-aryl (naphtho)quinones. Employing nitroalkanes as alk(en)ylating agents, these reactions are catalyzed by a bifunctional tertiary aminourea derivative and proceed via dynamic kinetic resolution (DKR). The resulting 2-aryl 3-alk(en)yl quinones exhibit rotational barriers characteristic of class 2 atropisomers and are isolated in good to excellent yields with generally exclusive ()-selectivity and high enantioselectivity. The synthetic utility of 2-aryl 3-alk(en)yl quinones is showcased through several stereospecific downstream transformations. Mechanistic studies reveal that the byproduct nitrite acts as the terminal oxidant in the alkenylation pathway. To the best of our knowledge, this is the first time nitroalkanes have been shown to function as alkenylating agents, at least in an enantioselective transformation.
Hori Y, Seki R, Mandai R
… +5 more, Furuta A, Iwasaki T, Nakajin K, Okuno Y, Nozaki K
J Am Chem Soc
· 2026 Jun · PMID 42340250
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Palladium-catalyzed oxidative functionalization of ethylene, exemplified by Wacker oxidation, has been fundamental in organic chemistry. Despite the potentially versatile reactivity of Pd-alkyl intermediates formed after...Palladium-catalyzed oxidative functionalization of ethylene, exemplified by Wacker oxidation, has been fundamental in organic chemistry. Despite the potentially versatile reactivity of Pd-alkyl intermediates formed after oxypalladation of ethylene, explorations of their subsequent reactions are limited due to the rapid β-H elimination. Here we found that the palladium acetate complex bearing a phosphine-sulfonate ligand containing a 2,5-dichlorothiophene-3,4-diyl backbone enables multiple ethylene insertion into the Pd-OAc bond by suppressing the competing β-H elimination. This reactivity provides access to heterotelechelic polyethylene and facilitates the copolymerization of ethylene with vinyl acetate or allyl acetate.