A series of Mg/Al and Mg/Al/Zr layered double hydroxides (LDHs) was prepared for use as catalysts in the Meerwein-Ponndorf-Verley (MPV) reaction of heterocyclic carboxaldehydes. Analysis of the solids revealed that zirconium is in fact incorporated into the LDH structure; as a result, their calcination produces Mg/Al/Zr oxides that are effective catalysts for the MPV reduction of heterocyclic compounds. In fact, the catalysts thus obtained exhibited higher activity than a catalyst obtained from an LDH containing Mg and At only. The reaction was conducted under very mild conditions (viz. atmospheric pressure and a temperature of 82 degrees C) and provided conversions close to 90 and 100% selectivity in all instances. (c) 2006 Elsevier B.V. All rights reserved.