Unsaturated lactams with endo- or exocyclic C-C double bonds constitute a set of reactive inputs that serve as the electron-rich olefin component in Povarov reactions. These substrates afford the multicomponent adducts in convenient yields and offer a wide range of structural diversity. Postcondensation transformations allow direct access to a variety of lactam-fused and amide-substituted quinoline derivatives.
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http://dx.doi.org/10.1021/ol902913j | DOI Listing |
J Org Chem
January 2025
Center for Analysis and Synthesis, Department of Chemistry, Lund University, Lund SE 221 00, Sweden.
A diastereospecific synthesis of vicinally substituted 2-oxazolidinones from α,β-unsaturated lactams using -chloroperoxybenzoic acid is reported. Several highly substituted 2-oxazolidinones were obtained in 19-46% yields in a one-pot reaction with complete control over the relative stereochemistry. The proposed reaction sequence consists of a Baeyer-Villiger oxidation, an epoxidation, and a concerted rearrangement.
View Article and Find Full Text PDFFront Microbiol
September 2024
Key Laboratory of Study and Discovery of Small Targeted Molecules of Hunan Province, School of Medicine, Hunan Normal University, Changsha, China.
Three sulfur-containing alkaloids aplospojaveedins A-C (1-3) with a hitherto undescribed carbon skeleton comprising octahy-dronaphthalene, , -unsaturated lactam and glycine-cysteine moieties were isolated from . Their structures were elucidated by 1D and 2D NMR spectroscopy, HR-MS, X-ray diffraction analysis, DFT-NMR and TDDFT-ECD calculations. A plausible biosynthetic pathway and putative targets are described.
View Article and Find Full Text PDFJ Org Chem
October 2024
Department of Chemistry & Biochemistry, Baylor University, 101 Bagby Ave, Waco, Texas 76798-7151, United States.
Enantioselective Giese reactions employing chiral α,β-unsaturated acylammonium salts and subsequent diastereoselective trapping followed by lactamization deliver optically active δ-lactams. Alkyl iodides bearing tosylamides undergo radical initiation using triethylborane at low temperatures to provide carbon-centered radicals to initiate the described organocascade. Subsequent diastereoselective inter- or intramolecular trapping of the incipient α-radical leads to highly functionalized, enantioenriched mono- and bicyclic δ-lactams (up to 99:1 er, > 19:1 dr) bearing up to three stereogenic centers.
View Article and Find Full Text PDFChem Commun (Camb)
October 2024
College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, China.
J Org Chem
October 2024
Department of Chemistry, School of Sciences and Humanities, Nazarbayev University, 53 Kabanbay Batyr Avenue, 010000 Astana, Kazakhstan.
Aza-annulation of enamines derived from β-ketoesters with maleic and itaconic anhydrides proceeds with excellent diastereoselectivity to provide functionalized γ- and δ-lactams. Further hydrolysis of the aza-annulation products resulted in dicarboxylic acids that underwent spontaneous decarboxylation under ambient conditions. The decarboxylation of β-γ unsaturated carboxylic acids with an electron-rich enamide C═C bond proceeds with the migration of the C═C bond and serves as a practical synthetic entry into 3-pyrrolin-2-ones and 1,2,3,4-tetrahydropyridin-2-ones.
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