98%
921
2 minutes
20
The convergent synthesis of bicyclo[2.2.2]diazaoctane structures using an intermolecular Diels-Alder cycloaddition between a pyrazinone and commercially available fumarate or maleate precursors is reported. High reactivity and stereoselection is observed with both dienophile substrates. Structure validation was achieved by conversion of cycloadducts into known [2.2.2]diazabicyclic compounds or into crystalline derivatives suitable for X-ray analysis. The cycloadduct derived from reaction of pyrazinone and maleic anhydride underwent selective anhydride ring opening and intersected an established precursor in the synthesis of brevianamide B.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6613383 | PMC |
http://dx.doi.org/10.1021/acs.joc.7b02403 | DOI Listing |
Int J Mol Sci
August 2025
Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, Av. Ferrocarril San Rafael Atlixco 186, Col. Leyes de Reforma 1A Sección, Iztapalapa, Ciudad de México C.P. 09310, Mexico.
A one-pot synthetic methodology that combines an Ugi-Zhu three-component reaction (UZ-3CR) with a cascade sequence (intermolecular Diels-Alder cycloaddition/intramolecular -acylation/decarboxylation/dehydration) using microwave-heating conditions, ytterbium (III) triflate (Yb(OTf)) as the catalyst, and chlorobenzene (for the first time in a multi-component reaction (MCR)) as the solvent, was developed to synthesize twelve new fluorinated-pyrrolo[3,4-]pyridin-5-ones containing a 4-amino-7-chloroquinoline moiety, yielding 50-77% in 95 min per product, with associated atom economies around 88%, also per product. Additionally, by in vitro tests, compounds and were found to effectively stop early SARS-CoV-2 replication, IC = 6.74 µM and 5.
View Article and Find Full Text PDFJ Phys Chem A
June 2025
Department of Chemistry, University of Rochester, Rochester, New York 14627, United States.
Coupling molecules to a quantized radiation field inside an optical cavity has shown great promise in modifying chemical reactivity. Using the parametrized quantum electrodynamic (pQED) polariton chemistry approach, we theoretically demonstrate that the ground state selectivity of a Diels-Alder (DA) reaction can be fundamentally changed by strongly coupling this reaction to the cavity, generating preferential Endo or Exo isomers which are formed with equal probability for the same reaction outside the cavity. The numerical performance of pQED is in good agreement with the high-level self-consistent QED coupled cluster approach due to the exact light-matter interaction term used in pQED.
View Article and Find Full Text PDFChem Commun (Camb)
July 2025
School of Chemistry and Chemical Engineering, Nanchang University, Nanchang 330031, China.
A highly diastereoselective Pd-catalyzed sequential reaction of -iodophenyl-ynones, propargylic ethers and maleimides is developed for efficient synthesis of tetracyclic succinimide derivatives containing three contiguous stereocenters and one exocyclic double bond. The reaction proceeds through Pd-catalyzed cross-coupling and propargyl Alder-ene reactions to generate a reactive indenone-allene intermediate, which undergoes an intermolecular Diels-Alder cycloaddition with maleimide to deliver a densely functionalized product. In addition, a formal four-component reaction was observed for generating polycyclic products bearing two succinimide motifs.
View Article and Find Full Text PDFOrg Biomol Chem
June 2025
Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi 712100, China.
A synthesis of the 6-5-5 tricyclic skeleton of the diterpenoid aberrarone is reported. The synthesis strategically features an intermolecular Diels-Alder reaction to construct the -hydrindane moiety and a cross-coupling-isomerization-intramolecular Alder-ene cyclization cascade to efficiently assemble the 6-5-5 tricyclic skeleton of aberrarone.
View Article and Find Full Text PDFMolecules
May 2025
Facultad de Ciencias, Universidad San Sebastián, Campus Ciudad Universitaria, Av. del Condor 720, Ciudad Empresarial, Huechuraba, Santiago 8580704, Chile.
The intramolecular Diels-Alder (IMDA) reactions of four substituted deca-1,3,9-trienes and one N-methyleneocta-5,7-dien-1-aminium with different electrophilic/nucleophilic activations have been studied within the Molecular Electron Density Theory (MEDT) and compared to their intermolecular processes. The topological analysis of the electron density and DFT-based reactivity indices reveal that substitution does not modify neither the electronic structure nor the reactivity of the reagents relative to those involved in the intermolecular processes. The analysis of the relative energies establishes that the accelerations found in the polar IMDA reactions follow the same trend as those found in the intermolecular processes.
View Article and Find Full Text PDF