Single-Site Cobalt Catalysts at New Zr12(μ3-O)8(μ3-OH)8(μ2-OH)6 Metal-Organic Framework Nodes for Highly Active Hydrogenation of Nitroarenes, Nitriles, and Isocyanides

We report here the synthesis of a robust and porous metal-organic framework (MOF), Zr-12-TPDC, constructed from triphenyldicarboxylic acid (H2TPDC) and an unprecedented Zr-12 secondary building unit (SBU): Zr-12(mu O3-)(8)(mu 3-OH)(8)(mu(2)-OH)(6). The Zr-12-SBU can be viewed as an inorganic node dimerized from two commonly observed Zr-6 clusters via six mu(2)-OH groups. The metalation of Zr-12-TPDC SBUs with CoCl2 followed by treatment with NaBEt3H afforded a highly active and reusable solid Zr-12-TPDC-Co catalyst for the hydrogenation of nitroarenes, nitriles, and isocyanides to corresponding amines with excellent activity and selectivity. This work highlights the opportunity in designing novel MOF-supported single-site solid catalysts by tuning the electronic and steric properties of the SBUs.