The exploration of emerging photocatalysts like covalent organic frameworks (COFs) is an essential but challenging endeavor to find sustainable solutions for selective organic transformations. Anthraquinones are envisaged to construct COFs for visible light photocatalysis because their derivatives are employed industrially as oxidation catalysts or organic dyes. Herein, an anthraquinone COF, TpAQ-COF, is successfully constructed with 1,3,5-triformylphloroglucinol (Tp) and 2,6-diaminoanthraquinone (AQ). Then, the selective oxidation of amines over TpAQ-COF is implemented. Amines can be effectively converted into corresponding imines over TpAQ-COF powered with green light and oxygen, during which superoxide radical anion is discerned as the pivotal reactive oxygen species. This work suggests that COFs could inherit the advantages of molecular building blocks for selective reactions powered with broad visible light.
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http://dx.doi.org/10.1016/j.jcis.2023.04.017 | DOI Listing |
The fusion kinetics of block copolymer micelles in dilute solutions have been investigated. As a model system, 1,2-polybutadiene--poly(ethylene oxide) micelles in the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate have been studied. The ionic liquid is a selective solvent for poly(ethylene oxide), promoting the self-assembly of the block copolymer into spherical micelles.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
March 2025
Research Centre for Natural Sciences: Termeszettudomanyi Kutatokozpont, Institute of Organic Chemistry, 2 Magyar tudósok körútja, 1117, Budapest, HUNGARY.
The anti-Markovnikov hydrofunctionalization of terminal, unactivated olefins is an evergreen synthetic challenge in organic chemistry. Several direct and indirect anti-Markovnikov methods have been developed, ranging from the classical hydroboration/oxidation protocol to state-of-the-art photoredox catalytic, transition metal complex-catalyzed and enzymatic procedures. Despite the ever-expanding suite of synthetic capabilities, these methods still have limited generality in their substrate scope, especially with nucleophiles.
View Article and Find Full Text PDFNanomaterials (Basel)
March 2025
Department of Chemistry and Biochemistry, California State University Long Beach, 1250 Bellflower Blvd., Long Beach, CA 90840, USA.
The availability of water-soluble nanoparticles allows catalytic reactions to occur in highly desirable green environments. The catalytic activity and selectivity of water-soluble palladium nanoparticles capped with 6-(carboxylate)hexanethiolate (C6-PdNP) and 5-(trimethylammonio)pentanethiolate (C5-PdNP) were investigated for the reduction of 4-nitrophenol, the oxidation of α,β-conjugated aldehydes, and the C-C coupling of phenylboronic acid. The study showed that between the two PdNPs, C6-PdNP exhibits better catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol in the presence of sodium borohydride and the selective oxidation of conjugated aldehydes to conjugated carboxylic acids.
View Article and Find Full Text PDFNanomaterials (Basel)
March 2025
Advanced Laser Technology Laboratory of Anhui Province, College of Electronic Engineering, National University of Defense Technology, Hefei 230037, China.
The compatibility of low infrared emission and wideband microwave absorption has drawn extensive attention, both theoretically and practically. In this paper, an infrared-radar-compatible stealth metasurface is designed using transparent conductive materials, namely indium tin oxide (ITO) and poly methacrylimide (PMI). The designed structure is a combination of a radar-absorbing layer (RAL) and a low-infrared-emission layer (IRSL), with an overall thickness of about 1.
View Article and Find Full Text PDFCells
March 2025
Faculté de Pharmacie, Université de Montréal, Montréal, QC H3C 3J7, Canada.
Macrophage mitochondrial dysfunction, caused by oxidative stress, has been proposed as an essential event in the progression of chronic inflammation diseases, such as atherosclerosis. The cluster of differentiation-36 (CD36) and lectin-like oxLDL receptor-1 (LOX-1) scavenger receptors mediate macrophage uptake of oxidized low-density lipoprotein (oxLDL), which contributes to mitochondrial dysfunction by sustained production of mitochondrial reactive oxygen species (mtROS), as well as membrane depolarization. In the present study, the antioxidant mechanisms of action of the selective synthetic azapeptide CD36 ligand MPE-298 have been revealed.
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