title: Strecker degradation of amino acids promoted by a camphor-derived sulfonamide.
abstract: A camphor-derived sulfonimine with a conjugated carbonyl group, oxoimine 1 (O2SNC10H13O), reacts with amino acids (glycine, L-alanine, L-phenylalanine, L-leucine) to form a compound O2SNC10H13NC10H14NSO2 (2) which was characterized by spectroscopic means (MS and NMR) and supported by DFT calculations. The product, a single diastereoisomer, contains two oxoimine units connected by a -N= bridge, and thus has a structural analogy to the colored product Ruhemann´s purple obtained by the ninhydrin reaction with amino acids. A plausible reaction mechanism that involves zwitterions, a Strecker degradation of an intermediate imine and water-catalyzed tautomerizations was developed by means of DFT calculations on potential transition states.
authors.affiliation: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1049-001 Lisboa, Portugal.
authors.forename: M Fernanda N N
authors.initials: MF
authors.lastname: Carvalho
authors.affiliation: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1049-001 Lisboa, Portugal.
authors.forename: M João
authors.initials: MJ
authors.lastname: Ferreira
authors.affiliation: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1049-001 Lisboa, Portugal.
authors.forename: Ana S O
authors.initials: AS
authors.lastname: Knittel
authors.affiliation: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1049-001 Lisboa, Portugal.
authors.forename: Maria da Conceição
authors.initials: Mda C
authors.lastname: Oliveira
authors.affiliation: Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais 1049-001 Lisboa, Portugal.
authors.forename: João
authors.initials: J
authors.lastname: Costa Pessoa
authors.affiliation: Institut für Physik, Universität Augsburg, Universitätsstr. 2, 86159 Augsburg, Germany.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Herrmann
authors.affiliation: University of Chester, Faculty of Science and Engineering, Department of Natural Sciences, Thornton Science Park, Pool Lane, Ince, Chester, CH2 4NU, UK.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Wagner
keywords: DFT calculations; NMR characterization; Strecker degradation; amino acids; camphorsulfonylimine