title: Metal-assisted Lossen rearrangement.
abstract: A new reaction mechanism for the Lossen rearrangement of hydroxamic acids catalyzed by basic salts is presented. It is shown that the rearrangement proceeds in metal complexes of deprotonated hydroxamic acids. The deprotonation can occur either at the oxygen atom (observed for the zinc complexes) or at the nitrogen atom (observed for the potassium complexes). Both anionic forms are characterized by infrared multiphoton dissociation spectroscopy. The rearrangements proceed from the reactive N-deprotonated metal hydroxamates and lead to metal carbamates. The mechanism is elucidated by computational chemistry, mass-spectrometric studies, and preparative experiments.
authors.affiliation: Department of Organic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030/8, 12843 Prague 2, Czech Republic.
authors.forename: Lucie
authors.initials: L
authors.lastname: Jašíková
authors.forename: Eva
authors.initials: E
authors.lastname: Hanikýřová
authors.forename: Anton
authors.initials: A
authors.lastname: Škríba
authors.forename: Juraj
authors.initials: J
authors.lastname: Jašík
authors.forename: Jana
authors.initials: J
authors.lastname: Roithová