Science China Chemistry最新文献

As important catalysts for C–C coupling, copper-based materials have great potential for electrocatalytic reduction of CO₂ to C₂₊ products. In this work, Cu₂O catalysts modified with different lanthanide hydroxides were successfully synthesized and used for CO₂ electroreduction. The results showed that compared with Cu₂O/Gd(OH)₃ and Cu₂O/Yb(OH)₃ catalysts, Cu₂O/La(OH)₃ exhibited the highest electrocatalytic performance for CO₂ reduction. This catalyst was able to maintain a high Faraday efficiency for C₂₊ products (({rm FE}_{{rm C}_{2+}})) of about 60% within the current density range of 400–800 mA cm⁻². The highest ({rm FE}_{{rm C}_{2+}}) reached 66% at 600 mA cm⁻² and the partial current density for C₂₊ products reached a maximum of 488 mA cm⁻². Meanwhile, the catalyst could run stably for 40 h with a remained ({rm FE}_{{rm C}_{2+}}) of about 60%. Multiple characterizations reveal that the introduction of La(OH)₃ promotes the formation of *CO intermediates, and also helps to stabilize the Cu(I) species in Cu₂O under cathodic potentials, thus facilitating the C–C coupling for C₂₊ production. This work provides a new strategy to enhance the C₂₊ production via stabilizing Cu(I).

Defect engineering is regarded as an effective strategy for enhancing gas-sensing performance in metal-organic frameworks (MOFs). However, precise control over defect types and their specific impact on gas-sensing properties remains a significant challenge. Herein, we propose a representative water-treatment approach to induce and regulate different defect types in various MOFs. Comparative structural analysis of ZIF-8 and ZIF-67, differing in metal centers, before and after water treatment, reveals that water molecules disrupt metal-ligand bonds, leading to metal defects in ZIF-8 via metal detachment and ligand defects in ZIF-67 through partial ligand loss. Gas-sensing results demonstrate that defect concentrations and gas-sensing capabilities in MOFs can be effectively modulated by controlling water treatment time. Notably, the presence of metal defects enhances the NO₂ response of ZIF-8 (20 ppm) by 2.63 times, while ligand defects improve the C₂H₄ response of ZIF-67 (25 ppm) by 3.96 times. Additionally, metal defect formation in MOF-74 is evidenced by a 2.97-fold enhancement in its response to 100 ppm acetone. Density functional theory calculations confirm that the defect sites enhance gas adsorption and sensing performance. This study offers new insights into defect engineering in MOFs, expanding the potential of defect-engineered MOFs for diverse applications.

Development of efficient and versatile methods for functional group transformations is one major objective in modern organic synthetic chemistry. α-Ketophosphonates are a class of bifunctional compounds playing a prominent role in organic and medicinal chemistry. However, their broader applicability has been hampered by lacking of direct and convenient synthetic methods from stable and abundant starting materials. Direct transformation of readily available and robust amides into labile α-ketophosphonates is thus highly desirable but remains a formidable challenge, as such a reaction is both kinetically and thermo-dynamically unfavorable, and there exists a chemoselective issue for the known bisphosphonylation. Herein, we report unprecedented versatile synthesis of α-ketophosphonates, α-hydroxyphosphonates and α,α-difluorophosphonates from either secondary or tertiary amides. The reactions are enabled by in situ electrophilic activation with trifluoromethanesulfonic anhydride (Tf₂O). The method features high efficiency, good chemoselectivity, wide substrate scope, excellent functional group tolerance, and easy scalability. The practicality of this methodology is highlighted by the late-stage functionalization of drug molecules and concise formal synthesis of an FBPase inhibitor.

The oxide-zeolite (OXZEO) bifunctional catalysts have gained significant attention as an effective strategy to address the selectivity challenges in direct syngas conversion beyond Fischer-Tropsch synthesis (FTS). In OXZEO catalysis, the metal oxide component is mainly responsible for activating CO and H₂, therefore determining the overall activity and product selectivity. Recent advances in sophisticated in-situ and quasi-in situ characterization techniques have shed light on the active sites of metal oxides and CO activation and its hydrogenation mechanism. This review focuses on these fundamental understandings, discussing the challenges and future directions.

Proteolysis-targeting chimeras (PROTACs) achieve therapeutic effects by degrading disease-related proteins but face limitations due to off-target toxicity caused by poor spatial control. To address this, we developed a near-infrared (NIR)-activated photocaged PROTAC platform that enables precise molecular spatiotemporal control over protein degradation. Two degraders targeting oncology-relevant proteins, breakpoint cluster region gene-abelson gene (BCR-ABL) and bromodomain-containing protein 4 (BRD4), showed light-dependent activation. NIR irradiation induced efficient target degradation (>70%) in cancer models, considerably improving therapeutic outcomes and reducing metastatic behavior. In animal studies, NIR-activated degraders demonstrated strong tumor suppression without detectable toxicity, outperforming light-restricted controls. Overall, this platform provides spatiotemporally controlled protein degradation with enhanced tissue penetration, offering a promising approach to reduce off-target effects in precision oncology.

Chirality is a fundamental geometric property that manifests across molecular and nanoscale systems, profoundly influencing physical, chemical, and biological processes. At the intersection of chiral chemistry and nanoscience, chiral nanomaterials have emerged as a transformative class of materials, exhibiting unique spin-dependent properties governed by the chiral-induced spin selectivity (CISS) effect. This quantum phenomenon, rooted in spin-orbit coupling and spin filtering mechanisms, enables precise modulation of electron spin polarization, unlocking new opportunities in catalysis, spintronics, and energy conversion. This review provides a comprehensive overview of the CISS effect in chiral nanomaterials, elucidating its underlying mechanisms—including spin-orbit interactions, spin filtering, and spin blockade—and surveying advanced techniques for characterizing both structural chirality and spin polarization. We further highlight emerging applications in electrocatalysis, photocatalysis, and spintronic device engineering. Despite significant progress, key challenges remain in unraveling the fundamental physics, achieving accurate spin characterization, and translating these phenomena into robust, scalable technologies. Continued interdisciplinary research into the rational design and functionalization of chiral nanomaterials is poised to drive breakthroughs in sustainable energy, next-generation catalysis, and quantum information technologies.

Zeolites, as one of the most important inorganic materials, have been widely applied in petrochemical and fine chemical industries for a long time, and one of the major topics in the field of zeolite synthesis is to control zeolite morphology with increased external surface areas, aiming to minimize mass transfer limitations and thus maximize access to micropores. Currently, it has been successfully synthesized zeolites with various morphologies such as nanoparticles, nanosheets, and nanoneedles. Herein, we briefly review recent progress for morphological control of zeolite crystals from organic templates including typically industrial zeolites of MFI, *BEA, MOR, FER, FAU, TON, MTW, and AEI structures as well as potentially important applications of zeolite such as UWY structure, which should be important for rational design of efficient zeolite-based catalysts in the future.

Transition metal-catalyzed allylic substitution is a key reaction for forming carbon-carbon and carbon-heteroatom bonds, with broad applications in organic synthesis. While most methods rely on “soft” stabilized nucleophiles, the use of “hard” unstabilized derivatives has been less explored due to their high reactivity and challenges associated with controlling regio- and stereoselectivity. This review highlights advances in catalytic allylic substitution with unstabilized organometallic nucleophiles, focusing on aryl, alkyl, allyl, alkenyl, alkynyl, benzyl, and allenyl reagents and their direct cross-coupling with acyclic and cyclic allylic substrates. Key developments are categorized by reaction type, including achiral, racemic, stereoselective, and stereospecific processes. These advancements provide deeper insight into the reaction progress, challenges, and limitations. We anticipate a better understanding of the underlying mechanistic intricacies will further broaden their applicability in target-directed synthesis.