(±)-Minfiensine (1) was synthesized in 10 steps in 26% overall yield with the 1,2,3,4-tetrahydro-9a,4a-iminoethanocarbazole core constructed through a [3+2] cycloaddition reaction between indole and an azaoxyallylic cation.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.jnatprod.7b00873 | DOI Listing |
Bioorg Chem
January 2025
N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences, Lavrentyev Avenue 9, Novosibirsk 630090, Russia. Electronic address:
Eudesmane-type sesquiterpene lactone isoalantolactone 1 is of great interest due to its availability, biological activity and synthetic application. Respective series of original spirocyclic (11S,5') (1,2,3-triazoline-eudesma-4,15-enolides) and (11S)-aziridine-eudesma-4,15-enolides were efficiently synthesized via a chemoselective 1,3-dipolar cycloaddition reaction of organic azides to the exocyclic double bond of the lactone ring of isoalantolactone or 13E-(aryl)isoalantolactones by heating in DMF or toluene. The thermal reactions of isoalantolactone with benzyl azide, 2-azidoethanol, or n-butyl azide in 2-methoxyethanol afforded 13-(alkyamino)isoalantolactones formed as a mixture of (Z) and (E)-isomers.
View Article and Find Full Text PDFBioorg Chem
January 2025
Department of Chemistry, Faculty of Science, Taibah University, Al-Madinah Al-Munawarah 30002 Saudi Arabia. Electronic address:
The discovery of novel anti-cancer drugs motivated us to synthesize a new series of triple 1,2,3-triazole-based arm scaffolds featuring distinct un functionalized alkyl and/or aryl side chains with possible anti-cancer action using the click chemistry approach under both conventional and green microwave irradiation (MWI) methods. The Cu(I) catalyzed cycloaddition reaction of targeted tris-alkyne with un functionalized aliphatic and aromatic azides has been adopted as an efficient approach for synthesizing the desired click adducts. Microwave irradiation improved the synthetic processes, resulting in higher yields and faster reaction times.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Organic Chemistry, Indian Institute of Science, Bangalore 560012, India.
Despite tremendous progress of dienamine catalysis along with its application in enantioselective synthesis over nearly two decades, certain limitations, especially with respect to the regioselectivity in the dienamine generation step, continue to persist. To overcome these shortcomings of classical dienamine catalysis, we now introduce the concept of alkoxy-directed dienamine catalysis and apply it to the enantioselective arene construction by desymmetrizing -enediones through [4 + 2]-cycloaddition. Catalyzed by a diphenylprolinol silyl ether, this reaction utilizes γ-alkoxy α,β-unsaturated aldehydes as the substrate and proceeds in a highly regioselective fashion through the intermediacy of δ-alkoxy dienamine.
View Article and Find Full Text PDFMolecules
December 2024
Department of Organic Chemistry, University of Valencia, Dr. Moliner 50, Burjassot, 46100 Valencia, Spain.
In this study, we investigated the [3+2] cycloaddition reaction of CFCN (TFAN) with nitrilimine (NI) to produce 1,2,4-triazole and compared the resulting isomers. We determined the preferred reaction pathway by examining the electrophilic and nucleophilic properties of the reaction substrates, performing thermodynamic calculations for the individual pathways, and comparing them with the experimental results.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Organisch-Chemisches Institut, Universität Münster, Corrensstraße 40, 48149 Münster, Germany.
Herein we report a simple BF-catalyzed cycloaddition of dihydropyridines with bicyclobutanes for the expedient synthesis of novel three-dimensional azacycle-fused bicyclo[2.1.1]hexane scaffolds.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!