Science China Chemistry最新文献

Two-dimensional transition metal oxides (2D TMOs) have drawn broad interest owing to their great potential for catalysis and energy storage applications, but suffered restacking and poor conductivity. Porous and conductive nanosheets are highly required, while suffering from inefficient synthesis. Here, we demonstrate interface-confined etching to synthesize mesoporous 2D metal oxides. Ultrathin porous MoO_3−x nanosheets are successfully synthesized with 2–3 nm thickness and abundant 3–5 nm diameter mesopores, ensuring high specific surface area and 10⁹-time improved conductivity when compared to the pristine sample. Consequently, 2D MoO_3−x delivers ultrahigh volumetric specific capacitance of 2003.2 F cm⁻³ and energy density of 94.1 Wh L⁻¹ at high power density of 1120 W L⁻¹, demonstrating great promise for energy storage. This work provides a promising way to synthesize 2D materials for high-performance energy storage.

Direct coupling of C–H bonds with organometallic reagents is a cornerstone of synthetic organic chemistry. However, achieving the direct coupling of C(sp³)–Si bonds with C–H bonds remains significantly challenging. In this study, we developed a ligand-assisted, silver-mediated intramolecular oxidative coupling strategy between unactivated organosilane (C(sp³)–Si) reagents and C(sp²)–H bonds. This method exhibits broad substrate tolerance, accommodating both electron-donating and electron-withdrawing substituents. It provides a straightforward and efficient approach to access a diverse range of tetrahydronaphthalene and tetrahydroquinoline scaffolds.

Despite notable advances, the acyclic alkyl iminium ion intermediates have not yet been tamed in the asymmetric aza-Friedel-Crafts reaction, owing to the paucity of efficient catalytic strategies to address the enantiodiscrimination challenge. Herein, a novel strategy to leverage asymmetric counteranion-directed Lewis acid catalysis with a silver phosphate is established. The intractable acyclic alkyl iminium ion intermediates are generated from bench-stable acyclic aliphatic N,O-aminals via α-fragmentation, which are stabilized by the chiral phosphate counteranion through the formation of a hydrogen-bonded ion pair. A variety of indoles have been employed in this catalytic strategy with the catalyst loading as low as 2 mol%, furnishing 3-indolyl methanamines with potential antiproliferative activities (IC₅₀ = 65.25 µM against 4T1 breast cancer cells) and versatile synthetic utilities. Density functional theory (DFT) calculations revealed that the enantioselectivity originates from the kinetically and thermodynamically favorable Re-face attack of indole on the Re-face of the iminium ion, assisted by C–H⋯π interactions within the hydrogen-bonded ion pair transition state. Beyond indoles, precise stereochemical control has also been achieved when smaller-sized pyrroles react with resonance-stabilized aryl iminium ion intermediates.

α-Aminonitriles and α-cyano amides are valuable structural motifs and versatile precursors with broad applications in medicinal and synthetic chemistry. Despite substantial progress, the development of general, mild, and highly selective methods for the synthesis of α-aminonitriles and α-cyanoamides via catalytic C–H cyanation remains challenging. Herein, we report a photoinduced, mild, and general strategy for α-C(sp³)–H cyanation of both cyclic and acyclic aliphatic amines under transition-metal-free and redox-neutral conditions. Furthermore, by integrating photoredox with copper catalysis, we establish an efficient approach to α-cyano amides, with the copper complex functioning as both photosensitizer and cross-coupling catalyst. These protocols exhibit excellent chemo-, regio-, and diastereoselectivity, broad substrate scope, and high functional group tolerance. Their versatility is further demonstrated through late-stage modification of bioactive molecules, underscoring the potential of these strategies for streamlined access to structurally complex cyano-containing compounds.

Electron transfer process (ETP) represents an efficient and robust pathway in peroxymonosulfate (PMS) activation, yet its practical application is limited by sluggish kinetics, inefficient electron transport, and constrained catalyst suitability. Herein, we design a roselike Ce-doped Co₃O₄ catalyst (RL Ce-Co₃O₄) with electron-deficient Co sites to enable efficient PMS activation by a selective ETP pathway in spinel oxide. Atomic-level Ce incorporation in Co₃O₄ induces electron delocalization of octahedral cobalt (Co_Oh) via 3d-2p-4f coupling orbital, constructing electron-deficient Co_Oh active sites with depopulated 3d orbitals. The roselike architecture improves the accessibility of active sites to further promote the reaction kinetics. Mechanistic insight reveals that the electron-deficient Co_Oh sites enhance the adsorption and stabilization towards both PMS and bisphenol A (BPA) by intensified Co-O covalent interactions. Meanwhile, Ce doping improves the electrical conductivity of Co₃O₄, promoting rapid electron transfer from BPA to PMS* via a catalyst bridge, thereby disrupting the conventional Co²⁺/Co³⁺ redox cycling and establishing a catalyst-mediated ETP pathway. Synergistically, RL Ce-Co₃O₄ exhibits superior performance, achieving 99.9% BPA degradation within 3 min with a first-order knetic constant (k_obs) of 1.61 min⁻¹, and ultra-long-term stability (106 h) in a scaled-up reactor system. This work provides an innovative concept to unlock a selective, accelerated ETP pathway in spinel oxides.

The development of innovative theranostic platforms that enable advanced therapies is crucial for advancing cancer treatment. Herein, we propose a molecular design integrating a π-conjugated luminogen with a boron cluster to create a hybrid agent for the combined and enhanced application of photothermal therapy (PTT) and boron neutron capture therapy (BNCT). As a proof of concept, we covalently anchored a nido-carborane cluster to a cyanine dye, constructing IRbiotin-nCB. Studies reveal the nido-carborane acts as an efficient photo-induced electron transfer (PET) donor, quenching fluorescence and enhancing the photothermal conversion efficiency to 33.9%—a significant improvement over the 23.9% efficiency of the parent cyanine. Furthermore, when evaluated as a boron delivery agent in vivo, IRbiotin-nCB demonstrated exceptional performance. At a low dose of 15 mg/kg, it achieved high tumor boron accumulation of 32.66 ± 0.85 µg/g, with superior selectivity evidenced by a tumor-to-blood ratio of 14.71 and tumor-to-normal tissue ratios consistently greater than 3. These values surpass the requisite thresholds for effective BNCT. By integrating optical activity for PTT and neutron capture capacity for BNCT within a single molecule, this hybrid platform enables a powerful synergistic therapy leading to complete tumor ablation, presenting a promising strategy for future cancer theranostics.