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Aziridination of olefins using nonprotected primary amines as nitrogen donors under oxidative conditions is highly desirable but poses challenges due to the incompatibility of nonprotected amines with oxidants. To address this issue, a strategy to leverage an internal oxidant is proposed. This method enables nucleophilic α- and β-additions of amines to conjugated hydroxamates, allowing for the assembly of complex aziridines from simple and safe building blocks. Benefiting from this internal oxidant concept, electron-rich anilines are directly employed to access -aryl aziridines. Beyond aziridination, olefin 1,2-diamination can also be achieved when secondary amines are used. Mechanistic studies suggest that an α-lactam intermediate is involved in this aziridination to enable the redox-transposition. In a broader context, this transformation represents a novel type of nucleophilic α-addition, which is rare compared to the more common β-addition (the Michael addition).
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http://dx.doi.org/10.1021/jacs.5c04286 | DOI Listing |
Nat Commun
August 2025
State Key Laboratory of Quantitative Synthetic Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
The clinical efficacy of the antidiabetic drug acarbose is hampered by degradation by the acarbose-preferred glucosidase (Apg) from K. grimontii TD1. Understanding the catalytic mechanism of Apg can aid the design of next-generation hypoglycemic pharmaceuticals acarbose analogs.
View Article and Find Full Text PDFBiosci Rep
August 2025
Institute of Bioinformatics and Structural Biology, College of Life Sciences and Medicine, National Tsing Hua University, Hsinchu, 30013, Taiwan.
Phosphopantetheine adenylyltransferase (PPAT) (PPAT; EC 2.7.3.
View Article and Find Full Text PDFCarbohydr Res
November 2025
Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, China. Electronic address:
Selenium, an essential micronutrient for human health, has garnered significant interest owing to its multifaceted biological activities including antioxidant, anti-inflammatory, and antitumor properties. In this study, 14 novel chitosan derivatives bearing selenourea groups were synthesized by incorporating selenium into chitosan via nucleophilic substitution reactions. Structural confirmation was achieved through FTIR, H NMR, and ICP-MS analyses, confirming successful selenium incorporation.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2025
Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry & Materials Science, Northwest University, Xi'an, 710069, P.R. China.
Heterocyclic replacements are crucial tools in medicinal chemistry, enhancing the physicochemical properties of lead compounds. Pyridine, a core structural motif in numerous drug candidates, often serves as a key heterocyclic scaffold. Nonetheless, a universally applicable synthetic strategy for the direct conversion of pyridines into a diverse array of other heterocycles has yet to be established.
View Article and Find Full Text PDFJ Am Chem Soc
August 2025
Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695 United States.
The biosynthesis of neuroexcitatory kainoids requires radical-mediated cyclization of -isoprenylated derivatives of l-glutamate catalyzed by nonheme iron and 2-oxoglutarate-dependent enzymes. While KabC and DabC from species of red algae catalyze this reaction during the biosynthesis of kainic acid and domoic acid, respectively, KabC can also produce a bicyclic lactone as an alternative reaction product. Herein, the radical-mediated catalytic pathways of KabC and DabC with the substrate -dimethylallyl l-glutamate are fully mapped demonstrating as many as three different product determining steps and competing processes of hydroxylation, C-C bond formation, intramolecular nucleophilic addition, desaturation and C-C bond cleavage leading to four different products including kainic acid, a bicyclic lactone, a hydroxylated product and oxidative rearrangement concomitant with elimination of formaldehyde.
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