Phosphorylated nitroso alkenes react with cyclic dienes such as cyclopentadiene or cyclohexadiene to afford hetero Diels-Alder-type cycloadducts where the nitroso alkene participates as dienophile component and the cyclic olefin acts as the 4π-electron (diene) system. Subsequent aza-Cope rearrangement affords highly functionalized 5,6-dihydro-4H-1,2-oxazines. Conversely, the reaction of TMS-substituted cyclopentadiene (dienophile) with nitroso alkenes as heterodienes leads directly to bicyclic 1,2-oxazines. Theoretical studies are in agreement with the experimental results and with the new aza-Cope rearrangement proposed.
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http://dx.doi.org/10.1021/jo201116u | DOI Listing |
Org Lett
December 2024
State Key Laboratory of Anti-Infective Drug Discovery and Development, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China.
A DNA-compatible three-component reaction is disclosed for the synthesis of on-DNA polysubstituted isoxazolidines that serve as privileged core scaffolds in numerous natural products and bioactive molecules. This one-pot approach involves the 1,3-dipolar cycloaddition of DNA-tagged styrenes with diazo compounds and nitrosoarenes in an aqueous solution of KOAc. The reaction demonstrates excellent functional group compatibility, providing a conventional protocol for the construction of a DNA-labeled isoxazolidine library.
View Article and Find Full Text PDFNeuropharmacology
March 2025
Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA; Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA; Functional Electrical Stimulation Center, Case Western Reserve University, Cleveland, OH, USA.
The primary objective of the present study is to provide further evidence that the endogenous S-nitrosothiol, S-nitroso-L-cysteine (L-CSNO), plays an essential role in signaling the hypoxic ventilatory response (HVR) in rodents. Key findings were that (1) injection of L-CSNO (50 nmol/kg, IV) caused a pronounced increase in frequency of breathing (Freq), tidal volume (TV) and minute ventilation (MV) in naïve C57BL/6 mice, whereas injection of D-CSNO (50 nmol/kg, IV) elicited minimal responses; (2) L-CSNO elicited minor responses in (a) C57BL/6 mice with bilateral carotid sinus nerve transection (CSNX), (b) C57BL/6 mice treated neonatally with capsaicin (CAP) to eliminate small-diameter C-fibers, and (c) C57BL/6 mice receiving continuous infusion of L-CSNO receptor antagonists, S-methyl-L-cysteine and S-ethyl-L-cysteine (L-SMC + L-SEC, both at 5 μmol/kg/min, IV); and (3) injection of S-nitroso-L-glutathione (L-GSNO, 50 nmol/kg, IV) elicited pronounced ventilatory responses that were not inhibited by L-SMC + L-SEC. Subsequent exposure of naïve C57BL/6 mice to a hypoxic gas challenge (HXC; 10% O, 90% N) elicited pronounced increases in Freq, TV and MV that were subject to roll-off.
View Article and Find Full Text PDFFuture Microbiol
November 2024
College of Pharmacy, Pusan National University, Busandaehak-ro 63 beon-gil 2, Geumjeong-gu, Busan, 46241, Republic of Korea.
Bacterial infections and the formation of biofilms are currently key factors in the delay of wound healing. S-Nitroso glutathione (GSNO) is recognized as a nitric oxide (NO) donor that exhibits potent antibacterial and antibiofilm activities. However, some of the stability limitations of NO require it to be prepared pharmaceutically.
View Article and Find Full Text PDFChem Commun (Camb)
August 2024
Department of Chemistry, Indian Institute of Technology Guwahati, Assam 781039, India.
An unprecedented example of a nitroso-azomethine(ene) reaction is reported. Nitroso-azomethine(ene) reaction-mediated unprecedented annulation of nitrosoarenes, azomethines, and alkenes to furnish arylquinolines arene functionalization of nitrosoarene has been developed. DFT studies provided mechanistic insights into the newly developed nitroso-azomethine(ene) reaction.
View Article and Find Full Text PDFJ Am Chem Soc
July 2024
Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
We report on the use of a simple, bench-stable [Fe(salen)]-μ-oxo precatalyst in the reduction of nitro compounds. The reaction proceeds at room temperature across a range of substrates, including nitro aromatics and aliphatics. By changing the reducing agent from pinacol borane (HBpin) to phenyl silane (HSiPh), we can chemoselectively reduce nitro compounds while retaining carbonyl functionality.
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