Reconstructed Hydrotalcite as a Highly Active Heterogeneous Base Catalyst for Carbon−Carbon Bond Formations in the Presence of Water

The aldol reaction of carbonyl compounds is efficiently catalyzed by reconstructed hydrotalcites, obtained by treating the Mg-Al mixed oxide with water, as solid base catalysts in the presence of water. The catalysis of the reconstructed hydrotalcites is attributable to the surface base sites, created during the organization of the layered structure, with uniformly distributed strength. Furthermore, the reconstructed hydrotalcites provide a unique acid-base bifunctional surface capable of promoting the Knoevenagel and Michael reactions of nitriles with carbonyl compounds.