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An efficient, highly atom economic synthesis of hitherto unknown spirocyclic pyrazolidines in a one-pot process was developed. The gold-catalyzed three-component coupling of alkynols, hydrazines and aldehydes or ketones likely proceeds via cycloisomerization of the alkynol to an exocyclic enol ether and subsequent [3 + 2]-cycloaddition of an azomethine ylide. A library of 29 derivatives with a wide range of functional groups was synthesized in up to 97% yield. With this new method, every position in the final product can be substituted which renders the method ideal for applications in combinatorial or medicinal chemistry.
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http://dx.doi.org/10.1039/c5ob02453f | DOI Listing |
J Org Chem
September 2025
Saint Petersburg State University, Universitetskaya Nab. 7/9, 199034 Saint Petersburg, Russian Federation.
A highly regioselective gold-catalyzed single oxygen transfer reaction, involving internal trifluoromethylated alkynes, pyridine -oxides, and nitriles, has been developed. The alkyne-attached CF-moiety functions through an inductive mechanism to direct -nucleophilic attack specifically to the β-alkyne position. This three-component transformation yields a diverse array of valuable 4-trifluoromethylated oxazoles in high yields (30 examples; up to 96%) under relatively mild gold-catalyzed conditions, demonstrating significant tolerance for various functional groups.
View Article and Find Full Text PDFJ Org Chem
May 2025
Key Laboratory of Chemical Biology of Hebei Province, College of Chemistry and Material Science, Hebei University, Baoding, Hebei 071002, P. R. China.
In the presence of Hantzsch ester and with JohnPhosAuCl/AgOMs as catalysts, a series of indole-fused iminosugars were obtained in good yields by the intramolecular reductive coupling reaction of iminosugar -glycoside, in which the terminal alkyne could be coupled with indole and further reduced to methyl. The substrates of iminosugar -glycosides were conveniently prepared by a three-component reaction of tosylated/mesylated sugar, propargylamine, and indole derivatives. The advantages of this protocol are its simplicity and efficiency in constructing the complex indole-fused iminosugars.
View Article and Find Full Text PDFJ Org Chem
July 2024
Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Ciudad de México 04510, México.
We describe herein a gold-catalyzed three-component reaction of -alkynylbenzaldehydes, aryldiazonium salts, and trimethoxybenzene. This process enables the one-pot formation of valuable isoindoles and 1,2-dihydrophathalazines. The regioselectivity of the reaction is dictated by the nature of the aryldiazonium salt.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2023
State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, China.
Activated alkyl halides have been extensively explored to generate alkyl radicals with Ru- and Ir- photocatalysts for 1,2-difunctionalization of alkenes, but unactivated alkyl bromides remain challenging substrates due to their strong reduction potential. Here we report a three-component 1,2-difunctionalization reaction of alkenes, unactivated alkyl bromides and nucleophiles (e.g.
View Article and Find Full Text PDFOrg Lett
January 2023
School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, Guangdong 510006, China.
A gold-catalyzed oxidative three-component reaction of terminal alkynes with alcohols and quinone monoimines has been disclosed, affording α-ketoacetals in good to excellent yields. By using quinone monoimines as electrophiles for the interception of the generated gold enolate intermediate, this one-pot process provides an unprecedented method for the polyfunctionalization of terminal alkynes through an oxidation-oxyalkylation-aryloxylation sequence, installing three oxygen atoms on the C-C triple bond.
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