Category Ranking
98%
Total Visits
921
Avg Visit Duration
2 minutes
Citations
20
Article Abstract
A novel metal-free double-annulation cascade for the construction of unusual fused heterocyclic systems is described. This simple protocol enables the sequential assembly of two rings in one pot from two simple precursors. Acidic conditions promote the condensation and the intramolecular alkynyl Prins reaction of an enyne or arenyne alcohol with a cyclic hemiaminal to form a five-, six-, or seven-membered oxacycle followed by a seven- or eight-membered azacycle. In this transformation, chemical complexity is rapidly generated with the formation of three new bonds (one C-O, one C-C, and one C-N) in one synthetic operation. The strategy is modular and relatively general, providing access to a series of unique fused bicyclic scaffolds.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.orglett.0c01351 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Tigliane glycosides from Euphorbia tirucalli as multidrug resistance modulators.
Bioorg Chem
September 2025
State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, People's Republic of China. Electronic address:
Chemical investigation of the twigs and leaves of Euphorbia tirucalli afforded six undescribed tigliane glycosides, tirucalosides A-F (1-6), together with 12 known diterpenoids (7-18). Compound 1 represents a rare carbon skeleton bearing a 5/7/5/4-fused ring system, while compound 6 contains an unusual seco-glucoside substitution. Their structures were determined by a combination of an extensive spectroscopic analysis and acid hydrolysis experiment.
View Article and Find Full Text PDFAlterisocoumarins A-M: Isocoumarins with anti-inflammatory and anti-tuberculosis activities from a mangrove endophytic fungus Alternaria sp. HN-17.
Bioorg Chem
August 2025
School of Pharmaceutical Sciences, Anhui Medical University, Hefei 230032, China. Electronic address:
Fifteen new isocoumarin derivatives 1-3, (±)-4, (±)-5, 6-10, (+)-11, (+)-12, and 13, together with eleven known analogues (-)-11, (-)-12, and 14-22 were isolated from the mangrove endophytic fungus Alternaria sp. HN-17. Their structures were unambiguously established by 1D/2D NMR and HRESIMS spectra, and electronic circular dichroism (ECD) calculations.
View Article and Find Full Text PDFTotal Synthesis of the Nominal Structure of (+)-Talaromyolide D.
J Am Chem Soc
August 2025
Department of Chemistry, New York University, New York, New York 10003, United States.
We describe a convergent and stereoselective total synthesis of the nominal structure of (+)-talaromyolide D (), a recently isolated secondary metabolite. This meroterpenoid features a unique pentacyclic skeleton distinguished by a fused 6/6/6 dihydroisocoumarin core and an unusual pendant dimethylcyclobutanol embedded within a sequence of four contiguous stereocenters. Our synthetic strategy was enabled by a stereoretentive, nickel-catalyzed electrochemical sp-sp decarboxylative cross-coupling, a two-fold bidirectional stitching sequence comprised of an oxime-directed β-C(sp)-H arylation and SAr to establish the central ring system of the target as well as a series of two late-stage carboxylic-acid-directed C(sp)-H oxidation reactions to ultimately access the isocoumarin lactone substructure.
View Article and Find Full Text PDFFused-Linked and Spiro-Linked N-Containing Heterocycles.
Int J Mol Sci
August 2025
A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Division of the Russian Academy of Sciences, 664033 Irkutsk, Russia.
Fused and spiro nitrogen-containing heterocycles play an important role as structural motifs in numerous biologically active natural products and pharmaceuticals. The review summarizes various approaches to the synthesis of three-, four-, five-, and six-membered fused and spiro heterocycles with one or two nitrogen atoms. The assembling of the titled compounds via cycloaddition, oxidative cyclization, intramolecular ring closure, and insertion of sextet intermediates-carbenes and nitrenes-is examined on a vast number of examples.
View Article and Find Full Text PDFTotal Synthesis of (+)-Pierisketone B.
J Am Chem Soc
August 2025
Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States.
We report herein the first total synthesis of (+)-pierisketone B, a bioactive diterpene that possesses a unique tetracyclic 7/5/6/5 carbocyclic framework that is punctuated with numerous stereocenters, two of which are quaternary and five of which are contiguous. The synthesis features an unusual Pauson Khand cyclization to generate the bridged tricyclic core. Creation of the requisite -fused hydrindanone moiety was achieved by hydroxyl directed hydrogenation of an allylic alcohol, and the A-ring of the natural product was formed by a Mukaiyama aldol reaction followed by a cyclization involving addition of a vinyl anion to a proximal ketone group.
View Article and Find Full Text PDF