Metal-Catalyzed "On-Demand" Production of Carbonyl Sulfide from Carbon Monoxide and Elemental Sulfur

The group 6 molybdenum(II) cyclopentadienyl amidinate (CPAM) bis(carbonyl) complex [Cp*Mo{N(iPr)-C(Ph)N(iPr)}(CO)(2)] (Cp*= eta(5)-C5Me5) serves as a precatalyst for the high-yielding photocatalytic production of COS from CO and S-8 under near-ambient conditions (e.g., 10 psi, 25 degrees C). Further documented is the isolation and structural characterization of several key transition-metal intermediates which collectively support a novel molybdenum(IV)-based catalytic cycle as being operative. Finally, in the presence of an excess amount of a primary amine, it is demonstrated that this catalytic system can be successfully used for the "on-demand" generation and utilization of COS as a chemical reagent for the synthesis of ureas.