Metal‐Containing Ionic Liquids as Efficient Catalysts for Hydroxymethylation in Water

Abstract

Abstract The iron‐containing ionic liquid butylmethylimidazolium tetrachloroferrate (bmim‐FeCl 4 ) proved to be an efficient and recyclable catalyst for the hydroxymethylation of β‐keto esters using aqueous formaldehyde and a low catalyst loading of up to 0.1 mol‐% without co‐solvents or additional surfactants. An useful and high‐yielding approach to hydroxymethylated keto esters as well as to 3‐disubstitued butyrolactones via tandem hydroxymethylation–lactonization could thus be established.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)