Herein, we disclose the first report on the generation of cyanonitrone from diazoacetonitrile and nitrosoarene, and its subsequent [3+2] cycloaddition with oxabicyclic alkenes to access fused tricyclic cyanoisoxazolidines. Further, this methodology could be extended to access fused tricyclic trifluoromethylated and phosphonylated isoxazolidines. Surprisingly, the reductive ring-opening of cyanoisoxazolidines was followed by a spontaneous lactonization to produce fused tricyclic amino lactones. Moreover, the N-O bond of the obtained tricyclic trifluoromethylated isoxazolidines could be cleaved to obtain 1,3-amino alcohols.
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http://dx.doi.org/10.1039/d2cc05831f | DOI Listing |
Eur J Med Chem
January 2025
Laboratory of Medicinal Chemical Biology, Department of Medicinal Chemistry, College of Pharmaceutical Sciences, Suzhou Medical College, Soochow University, 199 Ren'ai Road, Suzhou, 215123, PR China. Electronic address:
Pleurotin (1) is a benzoquinone meroterpenoid known for its wide-spectrum antitumor and antibiotic activities, notably acting as natural inhibitors of the thioredoxin reductase (TrxR). Pleurotin (1) has been chemically synthesized, but only in milligram quantities through at least 13 longest linear steps with 0.8 % overall yield due to its complex structure such as fused hexacyclic core with 8 contiguous stereocenters.
View Article and Find Full Text PDFAntibiotics (Basel)
December 2024
Medicinal Chemistry Laboratory, Department of Chemistry, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India.
The increasing prevalence of antimicrobial resistant highlights the urgent need for the new therapeutic agents. This study aimed to design and synthesize fused tricyclic benzimidazole-thiazinone derivatives (-) through a convenient method and evaluate their antimicrobial activity against various microorganisms. A series of fused tricyclic benzimidazole-thiazinone derivatives was rationally designed and synthesized in one pot by the reaction between trans substituted acrylic acids and 1-benzo[d]imidazole-2-thiol using coupling reagent TBTU (2-(1-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate).
View Article and Find Full Text PDFNat Commun
December 2024
National Key Laboratory of Green Pesticide, International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan, P.R. China.
Skeleton editing for heteroarenes, especially pyrazoles, is challenging and remains scarce because these non-strained aromatics exhibit inert reactivities, making them relatively inactive for performing a dearomatization/cleavage sequence. Here, we disclose a cycloaddition-induced scaffold hopping of 5-hydroxypyrazoles to access the pyrazolopyridopyridazin-6-one skeleton through a single-operation protocol. By converting a five-membered aza-arene into a five-unit spine of a 6/6 fused-bicyclic, this work unlocks a ring-opening reactivity of the pyrazole core that involves a formal C = N bond cleavage while retaining the highly reactive N-N bond in the resulting product.
View Article and Find Full Text PDFJ Org Chem
January 2025
Division of Organic Chemistry, CSIR-National Chemical Laboratory, Pune 411008, India.
6/5/3-Fused tricyclic enones were obtained when 4-(alkynyloxy)cyclohexa-2,5-dienones were treated with DMSO at 150 °C. The reaction proceeded via a four-membered oxathietene intermediate. The protocol developed is atom economical, has a broad substrate scope, and is amenable to gram-scale synthesis.
View Article and Find Full Text PDFOrg Lett
January 2025
Key Laboratory of Chemical Biology (Ministry of Education), Shandong Basic Science Research Center (Pharmacy), School of Pharmaceutical Sciences, Shandong University, Jinan, Shandong 250012, China.
Metabolic blockade-based genome mining of the marine sediment-derived SCSIO 07745 led to the discovery of 11 novel aminoquinolinone alkaloids, oxazoquinolinones A-J (-), characterized by an oxazolidone[3,2-α]quinoline-5,8-dione scaffold, and oxazoquinolinone K (), featuring an unprecedented fused 6/6/6/5 tetracyclic core ring system. Additionally, 5 new biosynthetic intermediates or shunt products (-) and a known metabolite sannanine () were identified. Their structures were elucidated by extensive spectroscopic analyses and a comparison of electronic circular dichroism and single-crystal X-ray diffraction.
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