title: The outcome of the oxidations of unusual enediamide motifs is governed by the stabilities of the intermediate iminium ions.
abstract: We compare the results from the oxidation of two unusual "enediamide" motifs (3,4-dihydropyrazin-2(1H)-ones), where a double bond is flanked by two amides. In one case the oxidation led to a ring-opened product arising from the cleavage of the double bond, and in the other a rare cis-dioxygenated compound was obtained. Both products have been characterized by X-ray crystallography. The outcomes of the key reactions are rationalized based on calculated free energies of intermediates.
authors.affiliation: School of Chemistry, The University of Sydney, Sydney, New South Wales, Australia.
authors.forename: Muneer
authors.initials: M
authors.lastname: Ahamed
authors.forename: Bun
authors.initials: B
authors.lastname: Chan
authors.forename: Paul
authors.initials: P
authors.lastname: Jensen
authors.forename: Matthew H
authors.initials: MH
authors.lastname: Todd
mesh_terms: D000577:Amides / Q000737:chemistry*; D018360:Crystallography, X-Ray; D007477:Ions; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D057786:Peptidomimetics / Q000138:chemical synthesis*; D011223:Praziquantel / Q000737:chemistry; D011719:Pyrazines / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000577:Amides; D007477:Ions; D057786:Peptidomimetics; D011719:Pyrazines; D011223:Praziquantel