Green Chemistry最新文献

Organic peroxidic bonds represent privileged scaffolds in both organic and medicinal chemistry. However, direct construction of peroxidic bonds (O–O) remains unreported in synthetic methodology, as conventional strategies rely on preactivated inorganic peroxo units derived from exogenous oxidants and oxygen sources, followed by their assembly onto organic molecules—approaches exhibiting inherent limitations in compatibility and safety. Herein, we present the utilization of low-cost and easily accessible oximes and enamides as paired oxygen donors. Under electrochemical oxidation, these substances directly generate oxygen species that are amenable to coupling, thereby enabling the formation of novel endoperoxides, specifically five-membered aza-peroxide rings, under mild and environmentally friendly catalytic conditions.

L,L-Lactide, the important precursor of biodegradable polylactic acid, has attracted significant attention. The one-step synthesis based on nanoconfinement primarily utilizes a porous catalyst to induce the directional cyclization of L-lactic acid dimers into L,L-lactide; however, the reported porous catalysts suffer from complex fabrication methods and high costs. We have developed a new Si-doped γ-Al₂O₃ catalyst via solid-phase grinding (SPG-Si-Al₂O₃), where the incorporation of trace Si precisely modulated the pore size to create an optimal spatial confinement environment for directing L-lactic acid conversion to L,L-lactide. After a 3 h 170 °C reaction of 0.5 g of 90 wt% L-lactic acid and 0.25 g of catalyst in 10 mL of o-xylene, L,L-lactide was obtained with a yield of 77.9% (determined using an HPLC external standard method), purity of 79.4% (determined by ¹H NMR), and 100% optical selectivity (analyzed by chiral GC). By increasing the amount of catalyst to 0.30 g, 82% yield and purity can be achieved; by prolonging the reaction time to 5 h, 92% yield and 83.3% purity were achieved. Furthermore, after mild leaching regeneration, the catalyst maintains an L,L-lactide yield of around 80% over 5 cycles. The proposed catalyst is simply synthesized and low-cost, and this work provides a simple, low-energy, and low-cost approach for L,L-lactide production.

The harmful effects of daily plastic use are increasingly evident, with most waste burned or landfilled, leading to the formation of microplastics that pollute the environment and the food chain. While the full impact remains unclear, photoreforming of plastics has emerged as a promising sustainable abatement method. This study demonstrates the commercial potential of P25 TiO₂ towards photocatalytic upcycling of polyethylene terephthalate (PET) microplastics by systematic exploration of the effect of co-catalysts, reaction temperature and oxygen presence on the generation of solar fuels and high-value liquid products. We demonstrate that while neat P25 yields minimal H₂ evolution, increasing the reaction temperature enhances its production significantly, and the addition of Pt further boosts H₂ generation by four orders of magnitude, resulting in 15.35 µmol h⁻¹ of H₂ and apparent quantum yield (AQY) values up to 0.45%. On par with H₂, we observe the generation of CH₄ from the reaction mixture, which we conclude to originate directly from PET rather than hydrogenation reactions. Liquid-phase analysis reveals diverse photoreforming products, including acetic acid, oxalic acid, formic acid and ethanol, with selectivity influenced by catalyst composition and reaction conditions. The feasibility of large-scale application of the process is further validated through prolonged irradiation tests using solar-simulated light and an upscaled setup, which demonstrate remarkable AQYs reaching 0.84%. These findings suggest PET photoreforming as a promising route for producing solar fuels and valuable chemicals, paving the way for sustainable plastic processing and upcycling.

Herein, we report an innovative metal-free catalytic electrochemical defluorination method for constructing C–S, C–Se, C–D, C–H, and C–C bonds. This approach offers excellent versatility, starting from simple trifluoroarylbenzene as a starting material and enabling coupling with disulfides, diselenides, thiols, silyl thioethers, and sulfonyl thioethers, which greatly extends the substrate range compared to conventional methods. Furthermore, variation of the solvent allows for controlled defluorofunctionalization, enabling hydrodefluorination (ArCF₂H), deuterodefluorination (ArCF₂D), complete hydrogenation (ArCH₃), and complete deuteration (ArCD₃). The deuterodefluorination proceeds with a high deuterium incorporation ratio. By employing a continuous flow reactor system, we have succeeded in expanding the reaction process while halving the reaction time, increasing productivity and practical applicability. This green synthetic protocol features multiple advantages including catalyst-free conditions, ambient temperature operation, and high atom economy, effectively avoiding the environmental concerns associated with transition metal catalysts. Particularly noteworthy is its excellent functional group tolerance and chemoselectivity, which enables precise molecular editing of fluorinated compounds.

Aluminum–graphite dual-ion batteries (AGDIBs) are emerging as a promising alternative in electrochemical energy storage due to aluminum's abundance, low cost, intrinsic safety, high power density, and excellent performance across a wide range of temperatures. Unlike single-ion rocking-chair batteries, AGDIBs operate via a dual-ion mechanism: Al plating/stripping at the Al anode and AlCl₄⁻ anions intercalation/deintercalation in the graphitic carbon cathode. Recent years have witnessed significant progress in the development of AGDIBs, particularly in anode interface engineering, graphite cathode optimization, and the formulation of novel electrolytes. Despite these advancements, critical challenges persist, including the low specific capacity of the graphitic carbon cathode and severe electrolyte-induced corrosion. This review offers a comprehensive and up-to-date analysis of recent advancements and persistent challenges in the development of AGDIBs. It systematically examines innovations across all components—including anodes, cathodes, electrolytes, and others—highlighting breakthroughs in materials design and performance optimization. Beyond summarizing progress, the review critically identifies unresolved issues and knowledge gaps, offering forward-looking insights to guide future research efforts.

The biochemical properties, functional characterization and substrate specificities of five recombinant glycosyltransferases – β-1,3-N-acetylglucosaminyltransferase (Cps1aI), β-1,4-galactosyltransferase (Cps1aJ), β-1,3-galactosyltransferase (Cps1bJ), and α-2,3-sialyltransferases (Cps1aK and Cps1bK) – involved in the biosynthesis of pentasaccharide repeating units of Group B Streptococcus (GBS) serotypes Ia and Ib capsular polysaccharides (CPSs) were systematically investigated. These recombinant enzymes were subsequently employed for a one-pot multi-enzyme cascade system to synthesize the pentasaccharide repeating units of GBS serotypes Ia and Ib CPSs, as well as their oligosaccharide derivatives. Using chemically synthesized Lacα-PP-(CH₂)₁₁-OPh as the initial substrate, the one-pot multi-enzymatic synthesis achieved satisfactory product yields ranging from 70 to 84%.

A series of novel aliphatic polysuccinates was synthesized from dimethyl succinate and various linear diols, with methylene chain lengths (n_CH2) ranging from 2 to 12 in their repeating units. The synthesis used an innovative and sustainable bulk polymerization method, greatly reducing solvent use and incorporating low-toxicity catalysts. This approach has enabled the production of a diverse array of polysuccinates for the first time, as evidenced by nuclear magnetic resonance. The crystallization behavior of these materials was systematically analyzed through a combination of Differential Scanning Calorimetry—encompassing non-isothermal, isothermal, self-nucleation (SN), and successive self-nucleation and annealing experiments—as well as in situ synchrotron Fourier–Transform Infrared Spectroscopy (FT-IR), Wide- and Small-Angle X-ray Scattering (WAXS/SAXS), and Polarized Light Optical Microscopy (PLOM). An intriguing even–odd effect was discovered across the entire range of n_CH2, with samples containing even chain lengths exhibiting superior property values compared to their odd counterparts. In the n_CH2 < 5 region, the even–odd effect is stronger, reflected in marked differences in thermal transitions and crystallization kinetics, attributable to variations in intermolecular interactions and unit cell structures, e.g., orthorhombic versus monoclinic. For n_CH2 > 5, the even–odd effect becomes less pronounced but does not reach saturation, presenting differences in thermal transitions, crystallization kinetics, and interplanar distance within the same unit cell. Remarkably, this study reports for the first time an even–odd effect in SN experiments, suggesting that the even–odd pattern in this series of polysuccinates lacks saturation, highlighting the complexity of these materials and their potential for further exploration in sustainable polymer chemistry.

The development of environmentally benign photocatalytic methodologies for [2 + 2] cycloadditions is of significant interest, given their utility in accessing cyclobutane motifs found in natural products and pharmaceuticals. Conventional approaches often rely on noble metal photocatalysts, harsh conditions, or organic dyes, limiting sustainability and scalability. Herein, we report a visible-light-driven, metal-free [2 + 2] photocycloaddition of chalcone and styrene derivatives using heterogeneous graphitic carbon nitride (g-CN). Mechanistic and DFT studies reveal an energy transfer (EnT) pathway rather than redox activation. This strategy demonstrates the potential of g-CN to expand beyond redox transformations toward sustainable energy-transfer-driven photocatalysis, offering a green and versatile route to cyclobutane frameworks.

Correction for ‘NAD(H) self-recycling whole-cell biocatalysis for the production of furoic acid and 2,5-furandicarboxylic acid from furfural via CO₂ fixation’ by Mingzhe Ma et al., Green Chem., 2025, 27, 10969–10973, https://doi.org/10.1039/D5GC03156G.

Poly(lactic acid) (PLA), a bioplastic currently with the highest production capacity, represents a promising alternative to traditional petroleum-based plastics. However, its slow degradation in natural environments and limited recycling options restrict its large-scale application. We recently discovered that diphenyl phosphate (DPP) can serve as a catalyst for PLA hydrolysis. Herein, to screen a more potent catalyst for PLA hydrolysis, various DPP derivatives are synthesized. We reveal that the catalytic degradation of PLA follows a dual activation mechanism, and the catalytic activity of these derivatives correlates positively with the electron deficiency of aromatic substituents. p-Bis-nitrophenyl phosphate (p-BNPP) with the strongest electron-withdrawing groups demonstrates the highest catalytic performance for PLA hydrolysis reported to date. Using just 3.5 wt% p-BNPP and a small amount of water, commercial PLA pellets/products are efficiently hydrolyzed into oligo(lactic acid) (OLA) with the average degree of polymerization below 4 within 30 min at 160 °C, without external pressure or organic solvents. p-BNPP can be reused at least 10 times and works well for other biodegradable polyester/polycarbonate hydrolysis. The resulting OLA can either be repurposed for producing high-quality PLA or transformed into a concentrated lactic acid solution. Additionally, this recycling flowsheet is successfully implemented in a kilogram-scale batch reactor.