title: Self-catalyzed Mannich-type reaction of enolizable cyclic 1,3-dicarbonyls to acyclic nitrones: an entry to functionalized β-enamino diones.
abstract: A new method for the preparation of highly functionalized β-enamino diones has been developed. The protocol involves an initial self-catalyzed Mannich-type reaction of enolizable cyclic 1,3-dicarbonyls to nitrones, followed by a spontaneous intramolecular reorganization of the resulting nonisolated hydroxylamine to enamino derivatives. These compounds retain the features of unnatural α-amino acids. The ease of preparation makes them attractive intermediates for the synthesis of peptidomimetics, polyheterocycles, and other multifunctional compounds. All experimental results have been efficiently rationalized by in silico studies at the M06-2X level of theory, and a valid mechanistic pathway has been proposed.
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Messina, V. le F. Stagno d'Alcontres 31, Messina 98166, Italy.
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Cordaro
authors.forename: Francesco
authors.initials: F
authors.lastname: Risitano
authors.forename: Angela
authors.initials: A
authors.lastname: Scala
authors.forename: Antonio
authors.initials: A
authors.lastname: Rescifina
authors.forename: Ugo
authors.initials: U
authors.lastname: Chiacchio
authors.forename: Giovanni
authors.initials: G
authors.lastname: Grassi
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D002384:Catalysis; D004146:Dioxanes / Q000737:chemistry*; D015394:Molecular Structure; D009589:Nitrogen Oxides / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000596:Amino Acids; D004146:Dioxanes; D009589:Nitrogen Oxides; C015388:nitrones