NaOH-promoted hydrogen transfer: Does NaOH or traces of transition metals catalyze the reaction?

Abstract

NaOH is revealed as an excellent catalyst for the hydrogen transfer of a wide range of aromatic and aliphatic ketones, which can be converted in high yields into the corresponding alcohols. The method is simple, cheap, uses a nontoxic and easy-to-handle catalyst, and does not require strictly anhydrous reagents, an inert atmosphere, transition metals, or any additional ligands. The pathway of this reaction is still debatable: is it a Meerwein-Ponndorf-Verley- like process or are traces of transition metals present in commercial NaOH responsible for the activity? Possible mechanisms of this surprising reaction are discussed. © 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.