Amination of Alcohols Catalyzed by Copper-Aluminium Hydrotalcite: A Green Synthesis of Amines

Copper-aluminium hydrotalcite (CuAl-HT)/K2CO3 has been employed in the activation of various benzyl alcohols with benzylamines to afford the corresponding amines in good to high yields. Experimentation showed that the reaction takes place through sequential transformations: the oxidation of alcohols into carbonyl compounds, imine formation between amines and carbonyl compounds, and then reduction of imines to amines, heterogeneously catalyzed by non-noble Cu-Al HT catalyst in a one-pot and straightforward fashion. The process was further extended to amination of alcohols with anilines, which are often resistant to alkylation reactions when substituted with strong electron-withdrawing groups. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)