Highly Efficient Cooperative Catalysis of Single-Site Lewis Acid and Brønsted Acid in a Metal-Organic Framework for the Biginelli Reaction.

A unique 3D framework containing three different types of nanoscale polyhedron cages was constructed by incorporating dinuclear [M2(μ2-OH)(COO)4] (M = Co, Ni) secondary building units and pyridyl-carboxylic-acid-supported tetracarboxylates. The assembled complexes possess isolated bifunctional single-site Lewis acid and Brønsted acid and can be used as highly efficient heterogeneous catalysts for the solvent-free Biginelli reaction with a high turnover frequency value of 338.4 h-1. Interestingly, a variety of 3,4-dihydropyrimidin-2(1 H)-ones have been obtained in high yields and short times.