title: Construction of functionalized tricyclic dihydropyrazino-quinazolinedione chemotypes via an Ugi/N-acyliminium ion cyclization cascade.
abstract: Dihydropyrazino-quinazolinedione chemotypes are complex and structurally challenging structures of biological interest, being found in the marine alkaloids such as brevianamide M-N and fumiquinazolines A-C. Herein we report the synthesis of this tricyclic system in three synthetic operations by means of an Ugi multi-component reaction (MCR) followed by a tandemN-acyliminium ion cyclization-intramolecular nucleophilic addition reaction sequence. Additional structural diversification for further library enrichment was also accomplished via sequentialN-alkylation andN-acylation/sulfonation.
authors.affiliation: Department of Chemistry and Biochemistry, the University of Arizona, Tucson, Arizona 85721 ; Department of Pharmacology and Toxicology, College of Pharmacy, BIO5 Oro Valley, the University of Arizona, Tucson, Arizona 85737.
authors.forename: Steven
authors.initials: S
authors.lastname: Gunawan
authors.forename: Christopher
authors.initials: C
authors.lastname: Hulme
keywords: N-acyliminium ion; Peptidomimetics; Ugi reaction; heterocycles; multi-component reaction