A novel Barton decarboxylation produces a 1,4-phenyl radical rearrangement domino reaction

• Published in: Tetrahedron Vol. 74; no. 38; pp. 5240 - 5247
• Main Authors: Manchado, Alejandro, García, Mercedes, Salgado, Mateo M., Díez, David, Garrido, Narciso M.
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 20.09.2018; Elsevier
• Subjects: Adrenaline; Amphetamine; Barton decarboxylation; Chemistry; Chemistry, Organic; Domino reaction; Ephedrine; Ethamphetamine; Phenethylamine; Physical Sciences; Radical rearrangement; Science & Technology; Barton decarboxylation; Ethamphetamine; Amphetamine; Adrenaline; Ephedrine; Phenethylamine; Radical rearrangement; Domino reaction; THIOHYDROXAMIC ESTERS; INVENTION; MICHAEL ADDITION; PURE LITHIUM AMIDES; AMMONIA EQUIVALENTS; AMINO-ACIDS; DERIVATIVES; CYCLIZATION; CONJUGATE ADDITION; ALKALOIDS
• ISSN: 0040-4020; 1464-5416
• DOI: 10.1016/j.tet.2018.05.043

A novel 1,4-Phenyl radical rearrangement (1,4-PhRR) is described in a typical Barton decarboxylation procedure. While carrying out this reaction in presence of a N,N-disubstituted β-amino acid derivative, the decarboxyphenyl rearranged derivative is obtained, as well as in presence of β-N,N-acylamide. On the other hand, secondary amines give the β-lactam derivative without rearrangement, as well as N-Fmoc derivatives give the normal decarboxylation reaction. In regards of amines which are far away from the carboxylic group, such as δ-amino acid derivatives, the reaction occur through a typical Barton decarboxylation without rearrangement. The diversity of the reaction proves synthetic usefulness paving the way to interesting biologically active compounds. [Display omitted]