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In this study, a Cu‐supported amine‐functionalized Fe3O4 nanocatalyst (Fe3O4‐NH2‐Cu) has been synthesized for A3 (amine, aldehyde, and alkyne) coupling reactions. The synthesized nanocatalyst was characterized by PXRD, FT‐IR, FESEM‐EDX, XPS, and VSM analysis. The catalytic action of the synthesized Fe3O4‐NH2‐Cu nanocatalyst was evaluated for A3 coupling reactions, with an excellent product yield of 97% in propargylamine synthesis and 98% in indolizines synthesis, respectively. The substrate scope of the catalyst was validated for various amines, substituted aryl aldehydes, and phenyl acetylene. The uniqueness of the synthesized nanocatalyst is effective performance of the catalyst under solvent‐free conditions and less reaction time for the aforementioned application. With the aid of an external magnet, the catalyst can be easily recovered from the reaction mixture and reused at least for five times without significant loss in catalytic activity, and its structural stability was confirmed by XRD, FT‐IR, and FESEM‐EDX analysis of the recovered catalyst. Overall, it is a green approach to synthesize simple Fe3O4‐NH2‐Cu catalytic system with magnetic recoverability, reusability, and recyclability for A3 coupling reactions under solvent‐free conditions with broad substrate scope. The proposed plausible mechanism is supported by DFT studies. [ABSTRACT FROM AUTHOR]

In this work, we present a facile method for accessing phenols through the ipsohydroxylation of arylboronic acid using delafossite silver ferrite (AgFeO2) functionalized with chitosan-derived nanodots (CDs) as a reusable catalyst (AgFeO2@CD). The catalyst, synthesized via the wet impregnation method, was characterized by Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and Brunauer–Emmett–Teller (BET) techniques. The ipsohydroxylation reaction conditions were optimized to achieve high catalytic efficiency, yielding up to 99% of the product at room temperature in an aqueous medium with hydrogen peroxide as a mild and environmentally friendly oxidant. The process generates water as the only by-product, ensuring cleanliness. The catalyst, recoverable with a simple external magnet, demonstrated no significant structural changes or loss in catalytic activity after five cycles, highlighting its reusability and recyclability. Furthermore, we investigated the potent antibacterial activity of AgFeO2@CD against Bacillus cereus, Escherichia coli, and Pseudomonas aeruginosa. The presence of Ag and CDs in the catalyst contributed to a significant reduction in pathogen growth, establishing it as an effective antibacterial agent. This multifunctional catalyst shows great promise in both catalysis and antibacterial applications, with its magnetic retrievability making it particularly valuable for ipsohydroxylation reactions.Graphical Abstract: In this work, we present a facile method for accessing phenols through the ipsohydroxylation of arylboronic acid using delafossite silver ferrite (AgFeO2) functionalized with chitosan-derived nanodots (CDs) as a reusable catalyst (AgFeO2@CD). The catalyst, synthesized via the wet impregnation method, was characterized by Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and Brunauer–Emmett–Teller (BET) techniques. The ipsohydroxylation reaction conditions were optimized to achieve high catalytic efficiency, yielding up to 99% of the product at room temperature in an aqueous medium with hydrogen peroxide as a mild and environmentally friendly oxidant. The process generates water as the only by-product, ensuring cleanliness. The catalyst, recoverable with a simple external magnet, demonstrated no significant structural changes or loss in catalytic activity after five cycles, highlighting its reusability and recyclability. Furthermore, we investigated the potent antibacterial activity of AgFeO2@CD against Bacillus cereus, Escherichia coli, and Pseudomonas aeruginosa. The presence of Ag and CDs in the catalyst contributed to a significant reduction in pathogen growth, establishing it as an effective antibacterial agent. This multifunctional catalyst shows great promise in both catalysis and antibacterial applications, with its magnetic retrievability making it particularly valuable for ipsohydroxylation reactions. [ABSTRACT FROM AUTHOR]

Motion dazzle markings comprise patterns such as stripes and zig-zags that are postulated to protect moving prey by making predators misjudge the prey's speed or trajectory. Recent experiments have provided conflicting results on their effect on speed perception and attack success. We focus on motion dazzle stripes and investigate the influence of four parameters—stripe orientation, stripe contrast, target size, and target speed—on perceived speed and attack success using a common experimental paradigm involving human "predators" attacking virtual moving targets on a computer touchscreen. We found that high-contrast stripes running parallel or perpendicular to the direction of motion reduce attack success compared to conspicuous uniform targets. Surprisingly, parallel stripes induced underestimation of speed, while perpendicular stripes induced overestimation of speed in relation to uniform black, suggesting that misjudgment of speed per se is sufficient to reduce attack accuracy. Across all the experiments, we found some support for parallel stripes inducing underestimation of target speed but these stripes reduced attack success only when targets were small, moved at an intermediate speed, and had high internal contrast. We suggest that prey features (e.g., size or speed) are an important determinant of capture success and that distortion of speed perception by a color pattern does not necessarily translate to reduced capture success of the prey. Overall, our results support the idea that striped patterns in prey animals can reduce capture in motion but are effective under a limited set of conditions. [ABSTRACT FROM AUTHOR]