Carvalho MFNN, Ferreira MJ, Knittel ASO, Oliveira MDC, Costa Pessoa J, Herrmann R, Wagner G. Strecker degradation of amino acids promoted by a camphor-derived sulfonamide.
Beilstein J Org Chem 2016;
12:732-44. [PMID:
27340465 PMCID:
PMC4902088 DOI:
10.3762/bjoc.12.73]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 03/24/2016] [Indexed: 11/23/2022] Open
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.
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