title: Metal-free α-amination of secondary amines: computational and experimental evidence for azaquinone methide and azomethine ylide intermediates.
abstract: We have performed a combined computational and experimental study to elucidate the mechanism of a metal-free α-amination of secondary amines. Calculations predicted azaquinone methides and azomethine ylides as the reactive intermediates and showed that iminium ions are unlikely to participate in these transformations. These results were confirmed by experimental deuterium-labeling studies and the successful trapping of the postulated azomethine ylide and azaquinone methide intermediates. In addition, computed barrier heights for the rate-limiting step correlate qualitatively with experimental findings.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA.
authors.forename: Arne
authors.initials: A
authors.lastname: Dieckmann
authors.forename: Matthew T
authors.initials: MT
authors.lastname: Richers
authors.forename: Alena Yu
authors.initials: AY
authors.lastname: Platonova
authors.forename: Chen
authors.initials: C
authors.lastname: Zhang
authors.forename: Daniel
authors.initials: D
authors.lastname: Seidel
authors.forename: K N
authors.initials: KN
authors.lastname: Houk
mesh_terms: D000586:Amination; D000588:Amines / Q000737:chemistry*; D001372:Aza Compounds / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry*; D008670:Metals / Q000737:chemistry*; D011809:Quinones / Q000737:chemistry*; D013237:Stereoisomerism; D013882:Thiosemicarbazones / Q000737:chemistry*
chemical_list: D000588:Amines; D001372:Aza Compounds; D001391:Azo Compounds; D008670:Metals; D011809:Quinones; D013882:Thiosemicarbazones; C512188:azomethine