The synthesis, structure, topology and catalytic application of a novel cubane-based copper(II) metal-organic framework derived from a flexible amido tripodal acid

A novel chiral metal-organic framework, [Cu-4(HL)(2)(H2O)(4)(MeO)(4)](n) (1), has been successfully synthesized from a tripodal flexible ligand (2S, 2'S, 2 '' S)- 2,2', 2 ''-(benzenetricarbonyltris(azanediyl)) tripropanoic acid (H3L). Compound 1 was characterized by IR and X-ray powder diffraction analysis. The structure was determined by X-ray single crystal diffraction analysis revealing that 1 possesses a 3D network, featuring a tetranuclear cubane-type secondary building block [Cu-4(MeO)(4)](4+), formed via the connection of four metal ions to four methoxide ions. These secondary building blocks are linked by four different HL2- ligands to construct a porous three dimensional framework of the dia topology with one-dimensional channels. Compound 1 also acts as a heterogeneous catalyst for the diastereoselective nitroaldol (Henry) reaction, providing high yields (up to 91%) and good diastereoselectivities under ambient conditions. This catalyst can be recycled without significant loss of activity.