Flavin has long been known to function as a single electron reductant in biological settings, but this reactivity has rarely been observed with flavoproteins used in organic synthesis. Here we describe the discovery of an enantioselective radical dehalogenation pathway for α-bromoesters using flavin-dependent 'ene'-reductases. Mechanistic experiments support the role of flavin hydroquinone as a single electron reductant, flavin semiquinone as the hydrogen atom source, and the enzyme as the source of chirality.
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http://dx.doi.org/10.1021/jacs.7b05468 | DOI Listing |
ACS Nano
January 2025
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
Transition-metal dichalcogenides (TMDs), such as molybdenum disulfide (MoS), have emerged as a generation of nonprecious catalysts for the hydrogen evolution reaction (HER), largely due to their theoretical hydrogen adsorption energy close to that of platinum. However, efforts to activate the basal planes of TMDs have primarily centered around strategies such as introducing numerous atomic vacancies, creating vacancy-heteroatom complexes, or applying significant strain, especially for acidic media. These approaches, while potentially effective, present substantial challenges in practical large-scale deployment.
View Article and Find Full Text PDFOrg Lett
January 2025
Department of Chemistry, Xihua University, Chengdu 610039, P. R. China.
A novel approach for the synthesis of pyrone and indanone derivatives utilizing Fe(III)-catalyzed reductive radical ring expansion of olefins and cyclopropenone has been proposed. The preliminary mechanism study shows that the alkyl radical is formed by hydrogen atom transfer, which can open the tension ring and then generate the intermediate. There are two paths for the intermediate: when there is a hydroxyl group at the β-position of the olefin, the reaction produces pyrones, and otherwise 1-indanone is generated.
View Article and Find Full Text PDFInt J Mol Sci
January 2025
Institute for Information Technologies Kragujevac, Department of Science, University of Kragujevac, Jovana Cvijića bb, 34000 Kragujevac, Serbia.
In this study, the antioxidant and prooxidant potency of protocatechuic aldehyde (PCA) was evaluated using density functional theory (DFT). The potency of direct scavenging of hydroperoxyl (HOO) and lipid peroxyl radicals (modeled by vinyl peroxyl, HC=CHOO) involved in lipid peroxidation was estimated. The repair of oxidative damage in biomolecules (lipids, proteins and nucleic acids) and the prooxidant ability of PCA phenoxyl radicals were considered.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Centro de Investigación en Ciencias-IICBA, Universidad Autónoma del Estado de Morelos, Cuernavaca 62209, Mexico.
The energy positions and wave function shapes of the ground and excited states of impurities, including resonance states, are studied using the expansion of the impurity wave function in basis functions. The structures under study are rectangular GaAs/AlGaAs quantum wells with four different widths. In all cases, the impurity binding energy (relative to the corresponding sub-band) has a maximum at or near the center of the quantum well, decreases as the heterointerface is approached, and apparently has a limit of 0 if the impurity moves deeper into the barrier.
View Article and Find Full Text PDFMolecules
January 2025
Dipartimento di Chimica, Sapienza Università di Roma, P.le Aldo Moro 5, 00185 Rome, Italy.
The main categories of transition metal-mercury heterometallic compounds are briefly summarized. The attention is focused on complexes and clusters where the {Hg-Y} fragment, where Y represents a halide atom, interacts with transition metals. Most of the structurally characterized derivatives are organometallic compounds where the transition metals belong to the Groups 6, 8, 9 and 10.
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