Efficient Catalysis of Knoevenagel Condensation by 1D Copper-Containing Heteropolyoxoniobate at Room Temperature

A 1D copper-containing organic-inorganic hybrid heteropolyoxoniobate, H3[K(H2O)6][K2(H2O)10]2[Cu(en)2(H2O)2][Cu(en)2(Nb6O19Cu(en))2]center dot 24H2O (HPONb 1), has been synthesized to heterogeneously catalyze Knoevenagel condensation at room temperature with high yields and cycling stability. The catalyst presents the best catalytic activity for Knoevenagel condensation among the polyoxometalates (POMs) reported to date. A 1D copper-containing organic-inorganic hybrid heteropolyoxoniobate catalyst for efficient catalysis of Knoevenagel condensation at room temperature.