By using enzymes, metal-containing cofactors, and related species, Nature has catalytically optimized selectivities and rates of numerous reduction and oxidation reactions, including reactions essential for sustaining life. Metal-oxygen adducts are known to catalyze selective oxidation reactions. The manganese/calcium-oxo cubane in the oxygen evolving complex in Photosystem II is an example, as is cytochrome P450 for catalysis of oxidative metabolism. For reduction and electron transport, Nature often uses enzyme co-factors that contain pairs or clusters of first-row transition metal ions coordinated, in part, by sulfur. Examples are Fe-Fe-and Fe-Ni-containing hydrogenases, molybdenum-iron (+sulfur), vanadiumiron (+sulfur), and all-iron (+sulfur) containing nitrogenases, and iron-sulfur cubanes for electron transport. Taking inspiration from Nature we want to explore stabilized, cluster-based metal-chalcogenide catalysts for reductive chemical transformations.