Catalysis by Hydrotalcite in Liquid-phase Organic Reactions

The interlayer Cl⁻ anions in a synthetic hydrotalcite-like material, Mg₆Al₂(OH)₁₆Cl₂.4H₂O, were found to react with organic bromides in a non-polar solvent of toluene, almost all chloride ions in the interlayer space appearing in the liquid phase as the corresponding organic chlorides. The hydrotalcite-like material was found to catalyze organic reactions in which the interlayer Cl⁻ anions play the role of catalyst. Thus, the material catalyzed the halide-exchange reactions between alkyl halides in toluene and the disproportionation of trimethoxysilane to give silane and tetramethoxysilane.