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Updated: Apr 23, 2026

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
Catalytic C-H activation of phenylethylamines or benzylamines and their annulation with allenes
Aleix Rodríguez1, Joan Albert, Xavier Ariza
1Departament de Química Orgànica, Facultat de Química, Universitat de Barcelona , Martí i Franquès 1, 08028 Barcelona, Spain.
Abstract:
Tetrahydro-3-benzazepines and tetrahydroisoquinolines are synthesized in one step from allenes and phenylethylamines or benzylamines, respectively. Mechanistically, it is assumed that activation of a C-H bond of an aromatic ring with Pd(II) occurs, directed by the primary amine, leading to the formation of a palladacycle into which an allene then undergoes insertion. The resulting π-allyl intermediate cyclizes to the products by an intramolecular allylic alkylation. The process is particularly useful with 2,3-butadienoates and amines having a quaternary carbon at the α-position.
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