A copper-catalyzed regioselective [3+2] annulation of malonate-tethered acyl oximes with isatins was developed, affording valuable 2,3-dihydrooxazole-spirooxindoles in moderate to good yields with excellent diastereoselectivity. The reaction sequence involves Cu(i) initiated N-O bond cleavage, 1,5-HAT and C-N bond formation. The protocol features mild reaction conditions and broad substrate scope. DFT calculations demonstrated that the [3+2] annulation pathway is more energetically favourable in both kinetics and thermodynamics.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1039/d0cc07995b | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
4-Alkyl-4-thieno[2',3':4,5]pyrrolo[2,3-]quinoxaline Derivatives as New Heterocyclic Analogues of Indolo[2,3-]quinoxalines: Synthesis and Antitubercular Activity.
Int J Mol Sci
January 2025
Postovsky Institute of Organic Synthesis, Ural Branch of the Russian Academy of Sciences, S. Kovalevskoy Street, 22, Ekaterinburg 620137, Russia.
The synthetic approach based on a sequence of Buchwald-Hartwig cross-coupling and annulation through intramolecular oxidative cyclodehydrogenation has been used for the construction of novel 4-alkyl-4-thieno[2',3':4,5]pyrrolo[2,3-]quinoxaline derivatives. For the first time, these polycyclic compounds were evaluated for antimycobacterial activity, including extensively drug-resistant strains. A reasonable bacteriostatic effect against HRv was demonstrated.
View Article and Find Full Text PDFRh(III)-Catalyzed Double Annulation of 3-Phenyl-1,2,4-oxadiazoles with 2-Diazo-1,3-diketones: Access to Pyran-Fused Isoquinolines.
Molecules
January 2025
School of Chemistry and Materials Engineering, Huainan Normal University, Huainan 232038, China.
Efficient access to pyranoisoquinoline derivatives via rhodium-catalyzed double C-H functionalization of phenyl oxadiazoles and diazo compounds has been developed. Two C-C bonds and one C-O and C-N bond formation was realized by this tandem reaction, along with the formation of two heterocycles, affording diversified pyran-fused isoquinolines in moderate to good yields with broad functional group tolerance under mild reaction conditions.
View Article and Find Full Text PDFCopper-Catalyzed Domino Annulation of Isoselenocyanates: A Pathway to Structurally Diverse , Se-Bis-Heterocyclic, and Fused Heterocyclic Compounds.
J Org Chem
January 2025
College of Chemistry and Chemical Engineering, Jishou University, Jishou 416000, People's Republic of China.
A copper-catalyzed domino addition/cyclization reaction was developed to synthesize novel benzoselenazole-linked 1,2,3-triazole and tetracyclic fused 12-benzo[4,5]selenazole[2,3-]quinazolin-12-one derivatives from isoselenocyanates. This domino reaction efficiently constructed multiple new chemical bonds in a single step, forming either four (one C-Se and three C-) or three (one C-Se and two C-) bonds. The reaction offers several key advantages, including mild conditions, broad substrate compatibility, and straightforward and safe operation.
View Article and Find Full Text PDFElectrochemistry-enabled Ir-catalyzed C-H/N-N bond activation facilitates [3+2] annulation of phenidones with propiolates.
Chem Commun (Camb)
January 2025
Institute of Medicine and Materials Applied Technologies, College of Chemistry and Chemical Engineering, Qufu Normal University, Qufu, Shandong 273165, China.
A mild and efficient [3+2] annulation of phenidones with propiolates has been developed to access -substituted indole alkylamides, enabled by merging electrochemistry with iridium catalysis using an undivided cell at room temperature. The mechanistic studies have confirmed that the electrochemically mediated catalytic cycle of Ir-Ir-Ir exhibits enhanced efficiency, mild reaction conditions, and unconventional selectivity.
View Article and Find Full Text PDFA Facile Approach to Tetracyclic Indolines: Highly Diastereoselective [4+2] Annulation of Indoles with Bicyclic N-Substituted Cyclobutanes.
J Org Chem
January 2025
Chang-Kung Chuang Institute, Shanghai Frontiers Science Center of Molecule Intelligent Syntheses, College of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China.
A new stereoselective [4+2] annulation method for constructing tetracyclic indolines by reacting indoles with bicyclic N-substituted cyclobutanes has been developed. Using Sc(OTf) as a catalyst, a series of tetracyclic indolines with four continued stereogenic carbon centers have been obtained in ≤86% yields as single diastereomers. This reaction offers an accessible way for the rapid construction of the core structures of biologically active natural products like paucidirinine, deethylibophyllidine, and ibophyllidine.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!