Acidic montmorillonite-immobilized primary amines (H-mont-NH2) were found to be excellent acid-base bifunctional catalysts for one-pot reaction sequences, which are the first materials with coexisting acid. and base sites active for acid-base tamdem reactions.: For example, tandem deacetalization-Knoevenagel condensation proceeded successfully with the H-mont-NH2, affording the, corresponding condensation product in a. quantitative yield. The acidity of the H-mont-NH2 was strongly influenced by the preparation solvent, and the base-catalyzed reaction's were enhanced by interlayer acid sites.