This study presents the synthesis of novel naphthofurano-iminosugars () using 2,3--isopropylidene D-ribose tosylate (), anilines (), and 1,4-benzoquinone () as starting materials through key iminium ion/enamine intermediates via [3 + 2] cyclization reactions at room temperature. The reaction has unique regioselectivity and stereoselectivity with moderate to excellent yields. The adaptability of this method has been demonstrated using various substituted anilines, on which both electron-donating and electron-withdrawing groups were well employed in the reactions. Notably, the treatment of the fused multicyclic iminosugar with TFA efficiently leads to an interesting unexpected pyridinium salt (), possible via four sequential steps: deprotection of the 2,3--isopropylidene group, furan ring opening, dehydration condensation of the OH groups, and elimination of water.
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http://dx.doi.org/10.1021/acs.joc.4c01360 | DOI Listing |
Molecules
December 2024
Key Laboratory of Chemical Biology of Hebei Province, College of Chemistry and Material Science, Hebei University, Baoding 071002, China.
An efficient and convenient strategy has been successfully developed for the preparation of novel hydroxylated alkaloid derivatives (also called fused multicyclic iminosugars) from -toluenesulfonylated sugars through a Pictet-Spengler-type mechanism. This method is highly stereoselective, does not require metal catalysts, and capable of conducting gram level reactions (with a 53% yield). Some of such iminosugars had an intermediate antiproliferative effect on HCT116 tumor cells.
View Article and Find Full Text PDFMolecules
November 2024
State Key Laboratory of Environmental Chemistry and Eco-Toxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
A divergent total synthesis of bioactive, naturally occurring decanolides, pinolidoxin and bellidisin C, was accomplished by taking advantage of chiral templates -ribose and -malic acid. In particular, bellidisin C, which is the first total synthesis so far, was achieved through a cascade reaction of reductive elimination and nucleophilic addition in a one-pot process and a sodium-alkoxide-promoted intramolecular lactonization as the key steps.
View Article and Find Full Text PDFOrg Lett
December 2024
Department of Chemistry, Indian Institute of Technology, Kharagpur, West Bengal 721302, India.
Development of metal-free conversion of naturally abundant phenols and anilines to the corresponding olefins remains a formidable challenge. The current state of the art relies on the TM-catalyzed Heck coupling of activated phenols (triflates, tosylates, and more) with the olefins. While these advancements are promising, the reaction suffers from branch vs linear selectivity and requires an expensive TM-ligand combination, hazardous organotin reagents, and very high reaction temperature.
View Article and Find Full Text PDFChem Asian J
November 2024
Department of Chemistry and Biochemistry, National Chung Cheng University, Chiayi, 621301, Taiwan.
Most of chemical sialylation reactions are conducted at extremely low temperatures to achieve the formation of challenging sialic acid linkages with high stereoselectivities. Performing chemical sialylation at room temperature independent of enzymatic methods represents an effective approach, particularly significant in biological and biochemical research. Our study aims to develop a convenient method of providing α-sialyl glycosides.
View Article and Find Full Text PDFChem Asian J
November 2024
Department of Chemistry, Institute of Science, Banaras Hindu University, Varanasi, Uttar Pradesh, 221005, INDIA.
The documented work highlighted the synthesis of bis(benzotriazol-1-yl) methane derivatives using silicomolybdic acid (SMA) and successfully implemented in the stereoselective synthesis of diverse pyrrolo[3,4-b]pyridin-5-one and pyridyl isoindolinones derivatives in one-pot. The pyridinamide precursor with diverse alkynes furnished Z-selectivity of pyrrolo[3,4-b]pyridin-5-one across exocyclic C=C bond while the various benzamides on treating with 2-ethynyl pyridine afforded (E)-pyridylisoindoline-1-ones as a major isomer. The single-crystal X-ray diffraction provides strong evidence in favor of the existence and orientation of developed compounds.
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