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1. Copper‐Catalyzed C(sp ³ )−H α‐Acetylation: Generation of Quaternary Centers

   https://doi.org/10.1002/anie.202418692  

   Okoromoba, Otome E; Chen, Ting‐An; Jang, Eun Sil; McMullin, Claire L; Cundari, Thomas R; Warren, Timothy H (January 2025, Angewandte Chemie International Edition)

   Abstract α‐substituted ketones are important chemical targets as synthetic intermediates as well as functionalities in natural products and pharmaceuticals. We report the α‐acetylation of C(sp³)−H substrates R−H with arylmethyl ketones ArC(O)Me to provide α‐alkylated ketones ArC(O)CH₂R at RT with^tBuOO^tBu as oxidant via copper(I) ‐diketiminato catalysts. Proceeding via alkyl radicals R•, this method enables α‐substitution with bulky substituents without competing elimination that occurs in more traditional alkylation reactions between enolates and alkyl electrophiles. DFT studies suggest the intermediacy of copper(II) enolates [Cu^II](CH₂C(O)Ar) that capture alkyl radicals R• to give R−CH₂C(O)Ar outcompeting dimerization of the copper(II) enolate to give the 1,4‐diketone ArC(O)CH₂CH₂C(O)Ar. 

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2. Quantification of the coupled dynamics of marine microbes and reactive oxygen species in laboratory batch culture experiments

   https://doi.org/10.1128/spectrum.00712-25  

   McCullough, Donna K; Bowden, Emily C; Calfee, Benjamin C; Gilchrist, Michael A; Zinser, Erik R; Talmy, David (June 2026, Microbiology Spectrum)

   Hom, Erik_F Y (Ed.)

   ABSTRACT Prochlorococcus, the smallest and most numerous phytoplankter of the oligotrophic surface ocean, is vulnerable to damage by the reactive oxygen species hydrogen peroxide (H₂O₂). The most harmful effects of exogenous H₂O₂are mitigated by detoxifying organisms, but even at low concentrations, the ecological and biogeochemical consequences of H₂O₂damage are not fully understood. Here, we present coupled ordinary differential equation models of the dynamics of diverse marine microbes grown in different levels of H₂O₂. We fit our model to monoculture time-series data of peroxide-sensitiveProchlorococcusand peroxide-resistantSynechococcus, picoeukaryotes, and bacteria. Our fits provide estimates of H₂O₂cell damage and detoxification rates in these ecologically important microbes. We find significant variation in rates of cell death and H₂O₂detoxification by taxonomy and H₂O₂concentration. Picoplankton (Micromonasspp. orOstreococcusspp.) and other previously investigated heterotroph helpers (Alteromonas) appear to upregulate detoxification when H₂O₂is elevated, whereasSynechococcusdetoxification rate does not vary with hydrogen peroxide concentration. As expected, elevated H₂O₂is damaging to high light-adaptedProchlorococcus, but they are capable of modest detoxification when H₂O₂concentration is relatively low. Our use of differential equation models to quantify parameters underlying microbe-H₂O₂dynamics provides a basis for ecosystem models to explore the impact of reactive oxygen species on cell mortality of different ocean microbes and computational exploration of H₂O₂impacts on microbial community composition. IMPORTANCEHydrogen peroxide produced naturally in the surface ocean is toxic to many abundant microbes that perform important ecosystem services such as carbon fixation. Much of the naturally occurring hydrogen peroxide produced in the surface ocean is detoxified by “helper” organisms. The healthy function of microbial communities may therefore depend upon the presence of different helpers. Mathematical models provide an important means to evaluate the impacts of hydrogen peroxide on ecosystem function. This study introduces a framework to evaluate the sensitivity of diverse microbes to hydrogen peroxide, in a manner that is amenable for inclusion in ecosystem models. It lays a foundation for future efforts to evaluate the impact of hydrogen peroxide on ecosystem function and microbial community composition. 

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3. 1-(Hex-5-en-1-yl)-4-{[3-methyl-2,3-dihydro-1,3-benzothiazol-2-ylidene]methyl}quinolin-1-ium iodide monohydrate

   https://doi.org/10.1107/S2414314622007970  

   Shank, Nathaniel; Stadler, Andrea L.; Barrett, Sean P.; Padgett, Clifford W. (August 2022, IUCrData)

   The title thiazole orange derivative, bearing an alkene substituent, crystallized as a monohydrate of its iodide salt, namely, (Z)-1-(hex-5-en-1-yl)-4-{[3-methyl-2,3-dihydro-1,3-benzothiazol-2-ylidene]methyl}quinolin-1-ium iodide monohydrate, C₂₄H₂₅N₂S⁺·I⁻·H₂O. The packing features aromatic π-stacking and van der Waals interactions. The water molecule of crystallization interacts with the cation and anionviaO—H...N and O—H...I hydrogen bonds, respectively. 

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4. Substrate-induced charge transfer and optical quenching in monolayer semiconducting TMDCs

   https://doi.org/10.1007/s41127-026-00113-8  

   Jaiswal, Suman; Tang, Chunli; Wang, Xinwei; Kuroda, Marcelo A; Jin, Wencan; Mahjouri-Samani, Masoud (August 2026, Graphene and 2D Materials)

   Abstract The optical and electronic properties of a two-dimensional (2D) material are profoundly influenced by the nature of its underlying substrate, thereby making the substrate-material interactions a vital factor for both fundamental studies and technological applications. These interactions can significantly modify the electronic structure and optical response of the 2D system, providing a powerful means to tailor and optimize their properties. In this study, we employ optical spectroscopy, including Raman and photoluminescence (PL) measurements, to probe the effects of the substrate on monolayer transition metal dichalcogenides (TMDCs): tungsten disulfide (WS₂) and tungsten diselenide (WSe₂). The films were synthesized by the laser-assisted synthesis technique (LAST) on silicon/silicon dioxide (Si/SiO₂) substrates and subsequently transferred onto interdigitated Si–Si/SiO₂platforms to study the effects of bare Si and Si/SiO₂surfaces on these materials. The optical response of the 2D single crystals on bare Si and Si/SiO₂substrates reveals pronounced substrate-induced modifications, underscoring the critical influence of the supporting surface. Portions of the monolayers of WS₂and WSe₂on the Si/SiO₂areas of the interdigitated substrate showed strong Raman and PL signals, while on the bare Si regions, these signals were relatively weaker or strongly suppressed. Additionally, strong PL quenching, approximately 10-fold for WS₂and 13-fold for WSe₂, was evident. A slight shift in the PL peak was also observed, which was more pronounced in WSe₂. We rationalize these observations via first-principles calculations identifying band alignments and surface interactions as the mechanisms producing the PL quenching in TMDCs on Si substrates. Our findings highlight the potential of substrate engineering to tune the optoelectronic performance of 2D materials for advanced device applications, thereby opening new perspectives in microelectronics. 

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5. Chloroplast Stress Signals Orchestrate Epidermis‐Specific Remodeling of Mitochondria and ER Under High Light

   https://doi.org/10.1002/advs.202514970  

   Angelos, Evan R; Choi, Hee‐Seung; Guo, Jingzhe; Zanini, Andrea A; Burch‐Smith, Tessa M; Snyder, Emily; Part, Matthew; van_de_Ven, Wilhelmina; Hur, Manhoi; Balcke, Gerd Ulrich; et al (January 2026, Advanced Science)

   ABSTRACT Environmental stress demands precise coordination among organelles to maintain cellular homeostasis. InArabidopsis, high light (HL) exposure triggers chloroplast‐dependent remodeling of mitochondrial and endoplasmic reticulum (ER) morphology specifically in adaxial and abaxial epidermal cells, but not in mesophyll cells. Live‐cell imaging reveals that HL rapidly suppresses mitochondrial motility, followed by fusion‐driven elongation and ER cisternal expansion. Inhibition of photosynthetic, but not mitochondrial, electron transport abolishes these changes, confirming chloroplast activity as the upstream trigger. Pharmacological analyses show that exogenous H₂O₂induces mitochondrial elongation, whereas calcium chelation blocks both H₂O₂‐ and HL‐induced responses, demonstrating that chloroplast‐derived H₂O₂activates a Ca²⁺flux essential for remodeling. Proteomic and functional studies identify the Ca²⁺‐binding GTPase MIRO1 as a central integrator of this pathway. MIRO1 overexpression mimics HL‐induced morphodynamics, while mutations disrupting its Ca²⁺‐binding or acetylation motifs abolish the response, establishing Ca²⁺‐dependent MIRO1 activity as a prerequisite for remodeling. Together, these findings reveal an epidermis‐specific, light‐responsive network in which chloroplast‐derived H₂O₂initiates Ca²⁺signaling through MIRO1 to coordinate mitochondrial and ER remodeling—a spatially restricted mechanism of organellar communication and stress adaptation at the plant–environment interface. 

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