TiO_2 nanoparticles(TiO_2 NPs) worked as an efficient heterogeneous catalyst in a one-pot,three-component,and solvent free Mannich reaction;producing variousβ-aminocarbonyls in good yields,and with good stereoselectivities.The catalyst was easily separated from the reaction mixture and was recycled four times with no significant loss of its catalytic activity. TiO 2 nanoparticles (TiO 2 NPs) worked as an efficient heterogeneous catalyst in a one-pot, three-component, and solvent free Mannich reaction; producing various β-aminocarbonyls in good yields, and with good stereoselectivities.The catalyst was easily separated from the reaction mixture and was recycled four times with no significant loss of its catalytic activity.