Communications Chemistry最新文献

Native chemical ligation (NCL) has emerged as the most extensively employed chemoselective reaction in chemical protein synthesis (CPS). Nevertheless, the inherently low reactivity of peptide alkyl thioesters often necessitates the use of excessive nucleophilic additives in NCL to facilitate the reaction. Herein, we describe a rapid, and additive-free peptide ligation reaction between peptide thioacid and N-terminal cysteinyl peptide without epimerization in the present vinyl thianthrenium tetrafluoroborate (VTT). VTT promotes quantitative and chemoselective activation of fully unprotected C-terminal peptide thioacids into thioester intermediates, which demonstrate exceptional reactivity, facilitating rapid NCL in an additive-free manner with high yields. This additive-free strategy is fully compatible with post-ligation desulfurization, allowing for a streamlined one-pot process that enhances the overall efficiency and simplicity of CPS workflows. The effectiveness of this methodology is demonstrated by synthesizing hyalomin-3 from two fragments through a one-pot thioesterification-ligation-desulfurization protocol and ubiquitin through a one-pot C-to-N sequential three-segment condensation (six steps in one pot).

Helices are present in the most important biomolecules (i.e., RNA, DNA). Helices are formed in biology and the laboratory using subunits with information encoded based on molecular recognition. The production of abiotic helical structures is an ongoing goal in synthetic and materials chemistry and has involved the development of organic and metal-organic materials that rely on complementarity of noncovalent forces (e.g. hydrogen bonds, coordination bonds) for helix formation. Herein, we describe a series of supramolecular isomers of three hydrogen-bonded organic cocrystals involving components that self-assemble and show progression at the structural level from a zig-zag chain to a double helix and to a quadruple helix. The isomers constitute a form of trimorphism involving a binary cocrystal system and we show that the polymeric structures can be interconverted through solvent-mediated phase transformations. We demonstrate the cocrystal involving the double helix to possess components that undergo an intermolecular [2 + 2] photodimerization in the crystalline state.

Increasing nitrate (NO₃^-) concentration in water bodies due to anthropogenic activities has become a leading environmental challenge of the 21st century. Electrochemical nitrate reduction reaction (eNO₃RR) offers a sustainable solution by simultaneously removing nitrates and producing ammonia, a valuable feedstock. However, eNO₃RR possesses significant challenges, such as efficiency, competing reactions, product selectivity, catalyst stability, etc. This review article highlights the importance of eNO₃RR, its mechanistic pathway, in-situ/operando techniques to understand the mechanistic pathway, reactor design, analytical challenges in product estimation, and catalyst designing strategies. This work uniquely integrates in-situ studies, mechanistic insights, and design principles to establish clear structure-activity correlations for advancing eNO₃RR catalysts. We conclude with current challenges and prospects to guide future research toward efficient and selective catalysts for eNO₃RR-driven ammonia production.

Many hydrogenation reactions still depend on noble-metal catalysts, which limits their broader use because of high cost and supply concerns. Developing effective catalysts from abundant materials that operate under mild reaction conditions remains a significant challenge. Here, we show the preparation of a copper silicate catalyst using an ammonia evaporation method that delivers exceptional performance in converting nitroarenes to anilines. The catalyst maintains high activity and stability, providing yields above 99 percent under mild conditions. Structural and surface analyses reveal well-dispersed copper species whose combined contributions promote both hydrogen activation and substrate conversion. This behaviour enables a cost-effective and sustainable alternative to noble-metal catalysts. The material also demonstrates robust recyclability, retaining activity over repeated use, and scale-up tests confirm its practical viability. These results highlight the promise of copper-based systems for efficient and industrially relevant hydrogenation processes.

Light-driven dissipative self-assembly has garnered substantial attention due to its precise spatiotemporal controllability. However, achieving synergistic integration of spatial manipulation fidelity, architectural programmability, and dynamic reconfigurability within a free-standing platform remains a formidable challenge. Herein, we report a light-driven hierarchical dissipative self-assembly paradigm with temporally programmable fluorochromism, achieved through molecular-engineered coordination of dynamic macrocyclic host-guest interactions within sustainable cellulose matrices. Protonated vinylpyridium-derived merocyanine is designed and synthesized to construct light-controlled differential binding architectures with cucurbiturils. This system demonstrates quantitatively reversible interconversion between spiropyran and merocyanine states through alternating photoactivation (475 nm) and thermal relaxation. Structural modulation of host-guest stoichiometry between 1:2 and 1:1 induces nanoscale morphological switching between spherical and cuboid assemblies, accompanied by time-resolved fluorescence chromism. Leveraging the inherent affinity between cucurbiturils and cellulose nanofibrils, we engineered light-fueled hierarchical architectures into freestanding cellulosic papers, exhibiting self-erasing transient photowriting and multilevel anti-counterfeiting functions. The non-covalent host-guest architecture and reprocessable cellulose matrix synergistically enable material recyclability. This spatiotemporally programmed dissipative self-assembly system pioneers sustainable cellulose platforms for adaptive optoelectronics and smart sensing.

This work presents a visual growth strategy based on water-induced phase transitions, which enables real-time tracking and structural regulation of Cs₄PbBr₆-to-CsPbBr₃ microcrystal transformation under ambient conditions without the need for high-energy beams or vacuum. Driven by the difference in the dissolution rates of CsBr and PbBr₂ in water, the slow progression of the reaction interface allows clear observation of crystal morphology evolution under a conventional fluorescence microscope. The microcrystals obtained through strategy possess highly regular structural morphology and superior optical properties. In the experiments, micron-scale-wire exhibiting size-dependent polarized emission and bulk-microcrystals supporting multimode lasing emission were successfully constructed. Further analysis revealed the significant influence of crystal size on excited-state dynamics, cavity mode selectivity, and emission characteristics, thereby establishing a direct link between structural visual regulation and functional photon output. This work delivers mechanistic insights and experimental evidence for controllable fabrication of low-threshold lasers and polarized light-emitting devices.

The use of weak, inexpensive bases in the assembly of late-transition metal NHC complexes represents a most promising synthetic strategy. We now disclose the use of gaseous and aqueous ammonia as bases for the continuous-flow synthesis of these complexes with Au, Pd, and Cu metal centers. The fully homogeneous system enables reactions to proceed under milder, faster, and more concentrated conditions than state-of-the-art methods.

Metal-organic frameworks (MOFs) are porous crystalline materials whose adjustable structures make them increasingly attractive for biomedical engineering. Yet, developing sustainable routes to control their pore features remains a challenge. In this study, we explored how synthesis time can act as a simple and eco-friendly lever for pore engineering in MIL-125(Ti). By varying only the reaction duration, we created a series of MOF variants with distinct morphologies, pore sizes, and surface areas, each optimized for drug delivery and gene-editing applications. Detailed analyses using BET, XRD, and FESEM, supported by mathematical modeling, showed that synthesis time directly shapes crystallinity, porosity, and biocompatibility. Notably, the 24-hour sample displayed the highest surface area and pore volume, suitable for sustained drug release, while shorter synthesis times yielded frameworks favorable for other therapeutic uses. Overall, our findings introduce the concept of a sustainable pore size as a practical approach to designing high-performance biomedical materials.

Arenes play a crucial role in various fields of chemistry. Since Kekulé proposed the molecular structure of benzene in 1865, chemists have been working to develop methods for preparing functionalized arenes. Most of these methods focus on introducing functional groups through substitution reactions (electrophilic aromatic substitution, cross-coupling, C-H activation) using aromatic starting materials. In contrast, the formal [2 + 2 + 2] cycloaddition of three different alkyne moieties allows for the introduction of functional groups before synthesizing the aromatic core. Although straightforward, this strategy faces challenges, including the inherent reactivity of heteroatom-substituted alkynes, restrictions on the substitution patterns of the alkynes, and the use of noble metal-based catalysts. Herein, we report an iron-catalyzed cyclotrimerization of internal and terminal alkynes to provide densely functionalized aromatic products. The method accommodates alkoxy-, amido-, and even boryl alkynes, yielding the corresponding aryl ethers, amides, or boronic acids in up to quantitative yields at moderate temperatures within minutes.

Achieving molecular chirality with enantiostability in purely π-conjugated foldamers remains a substantial challenge due to inherently weak π-π stacking interactions and facile racemization. Herein, we introduce a novel design strategy employing synergistic intramolecular 3D π-π stacking networks within a 1,8-diarylnaphthalene framework, enabling foldamers to exhibit extraordinary configurational stability. A systematic series of quinoxaline- and phenazine-based foldamers incorporating carbazole (CZ) and diphenylamine (DPA) donors were synthesized, with chiral configurations stabilized through complementary face-to-face and laterally offset π-π stacking interactions. Single-crystal X-ray analyses and computational studies confirmed the formation of complex intramolecular π-networks, providing exceptional racemization barriers (ΔG^‡ up to 26.06 kcal mol^-1), exceeding conventional atropisomers. Additionally, the modular donor-acceptor design facilitates full-color circularly polarized luminescence (469-684 nm), maintaining high dissymmetry factors (|g_lum | > 10^-3) across solution and solid-state environments. This work establishes a generalizable principle for constructing chiral foldamers with enantiostability and tunable optical properties through tailored 3D aromatic interactions, offering significant advances in chiral optoelectronics and responsive materials.