Mechanistic studies on a Cu-catalyzed aerobic oxidative coupling reaction with N-phenyl tetrahydroisoquinoline: structure of intermediates and the role of methanol as a solvent

Esther Boess; Devarajulu Sureshkumar; Abhishek Sud; Cornelia Wirtz; Christophe Farès; Martin Klussmann

doi:10.1021/ja201610c

Mechanistic studies on a Cu-catalyzed aerobic oxidative coupling reaction with N-phenyl tetrahydroisoquinoline: structure of intermediates and the role of methanol as a solvent

J Am Chem Soc. 2011 Jun 1;133(21):8106-9. doi: 10.1021/ja201610c. Epub 2011 May 11.

Authors

Esther Boess¹, Devarajulu Sureshkumar, Abhishek Sud, Cornelia Wirtz, Christophe Farès, Martin Klussmann

Affiliation

¹ Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany.

PMID: 21561084
DOI: 10.1021/ja201610c

Abstract

The mechanism of an aerobic copper-catalyzed oxidative coupling reaction with N-phenyl tetrahydroisoquinoline was investigated. The oxidized species formed from the reaction of the amine with the copper catalyst were analyzed by NMR-spectroscopy. An iminium dichlorocuprate was found to be the reactive intermediate and could be structurally characterized by X-ray crystallography. The effect of methanol to effectively stabilize the iminium ion was investigated and shown to be beneficial in an oxidative allylation reaction.