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Herein, we have described a novel organocatalytic approach to access biologically important dihydropyridin-2-ones in a one-pot way with generally high yields (up to 99%) and excellent enantioselectivities (up to 99% ee). This reaction proceeded via a new dual activation mode, including in situ-generated α,β-unsaturated acylazoliums and 4-dimethylaminopyridinium salts that underwent a Michael addition/1,4-H migration/lactamization sequence. The base-triggered 4-dimethylaminopyridinium ylide formation pathway over the competing substitution reaction pathway of vicinal haloamines is noteworthy. [ABSTRACT FROM AUTHOR]

The rise of biological invasions threatens biodiversity and food security, with the vespid family, including Vespa soror, being of particular concern. Our study focused on the alarm pheromone components of V. soror. By using gas chromatography‐mass spectrometry (GC‐MS) chemical analyses, electroantennograms, and field bioassays, we identified 5 compounds—2‐pentanol, 3‐methyl‐1‐butanol, 2‐heptanol, 2‐nonanol (2‐N), and isopentyl acetate (IPA)—in hornet sting venom that elicited defensive behavior from hornets. IPA and 2‐N also serve as alarm pheromone components in multiple honey bee species that are important prey for V. soror. This shared chemical signaling may allow cross‐detection by each species on the other's alarm cues. While it should be advantageous for bees to detect V. soror alarm pheromone, the benefits to V. soror of using IPA and 2‐N are unclear. V. soror may manipulate bee behavior, potentially distracting defenders, because they mark victim bee colonies by rubbing their abdomens, which contain their sting glands, at bee hive entrances. Our findings pose new evolutionary questions about the role of manipulation in the arms races. [ABSTRACT FROM AUTHOR]

A dearomative [4 + 2] cycloaddition of 3‐nitroindoles ortho‐amino Morita−Baylis−Hillman carbonates was established under mild conditions. This method provides an efficient and practical approach for delivering tetrahydro‐5H‐indolo[2,3‐b]quinolines containing three contiguous stereocenters, two tertiary and one quaternary, in high yield (up to 95%) with excellent diastereoselectivity (all cases >25:1 dr). The potential synthetic applications of this strategy were also highlighted by the scale‐up experiment and further synthetic transformation. Moreover, the structure and relative configuration of the cycloadduct was unequivocally confirmed by single‐crystal X‐ray diffraction. [ABSTRACT FROM AUTHOR]

ABSTRACT A formal [3 + 3] cycloaddition of 4‐hydroxycoumarins with propargylicalcohols was established under mild conditions. This strategy utilizes diazonium tetrafluoroborate as the Lewis acid catalyst and provides a practical approach for delivering pyranocoumarin derivatives in moderate to high yield. The structure of the cycloadduct was unequivocally confirmed by single‐crystal x‐ray diffraction. The potential synthetic applications of this strategy were also highlighted by the scale‐up experiment and further synthetic transformation. [ABSTRACT FROM AUTHOR]

Di-(2-ethylhexyl) phthalate (DEHP) and microplastics (MPs) are emerging contaminants frequently detected in the marine environment. However, the influence of MPs on DEHP bioaccumulation and their combined effects on eco-environmental risks remain underexplored. Mytilus coruscus (M. coruscus) were exposed to DEHP (200.0 µg/L), polystyrene (PS) (0.050, 0.50, and 5.0 mg/L), and their combination at environmentally relevant concentrations for 15-day, followed by a 7-day depuration period. The amount of DEHP accumulation followed the order of digestive gland > gills > muscles > gonad, with PS dose-dependently amplifying DEHP bioaccumulation in digestive gland. The changes in antioxidant enzyme activity indicated disruptions in oxidative defense. Furthermore, metabolomic analysis revealed that PS and DEHP considerably altered the lipid, energy, and citric acid cycles in digestive gland and gonad. Post-depuration analysis showed combined exposure resulted in persistent effects. Compared with single exposures, combined exposure had a greater adverse effect on the metabolism of essential amino acids, fatty acids, and volatile compounds, potentially influencing edibility and nutritional value of M. coruscus. This study underscores cumulative eco-environmental toxicity of PS and DEHP toward M. coruscus and highlights the potential increased risks of co-pollution., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)