Unexpected copper mediated benzyl O→O migration during an Ullmann ether coupling

Corinne Vanucci-Bacqué (1) , Slim Chaabouni (1) , Isabelle Fabing (1) , Florence Bedos-Belval (1) , Michel Baltas (1)

1 SPCMIB - Synthèse et Physico-Chimie de Molécules d'Intérêt Biologique

The synthesis of a highly functionalized phenolic diaryl ether 5,5′-oxybis(4-hydroxy-3-methoxybenzaldehyde) (1) potentially interesting as a new scaffold for drug design, has been carried out using Ullmann coupling conditions. An unusual benzyl migration in o-benzyloxyphenol moiety occurred during this reaction leading to an unexpected compound identified as 4-(benzyloxy)-3-(2-(benzyloxy)-4-formyl-6-methoxyphenoxy)-5-methoxy benzaldehyde (7). A rationale for this migration process is proposed.

Mots clés: Diaryl ether; Ullmann condensation; Benzyl migration; Phenol dimers

Domaines: Chimie

Corinne Vanucci-Bacqué, Slim Chaabouni, Isabelle Fabing, Florence Bedos-Belval, Michel Baltas. Unexpected copper mediated benzyl O→O migration during an Ullmann ether coupling. Tetrahedron Letters, 2014, 55 (2), pp.528-530. ⟨10.1016/j.tetlet.2013.11.089⟩. ⟨hal-02444249⟩