This talk will present the first reported case for direct, catalytic synthesis ofcarbonyl sulfide (COS), a possible condensing agent in the formation of peptidesunder primordial conditions, from its most basic components, namely, carbonmonoxide (CO) and elemental sulfur (S8). The photolytic reaction proceeds atroom temperature and is catalyzed by a molybdenum complex supported by thepentamethylcyclopentadienyl (C5Me5) amidinate [N(iPr)C(Ph)N(iPr)] (CpAm) ligandenvironment. All reaction intermediates have been identified and structurallycharacterized, and it was found that addition of acetonitrile (NCCH3) to the reactionmixture lead to increased reaction rates by preventing the formation of thethermodynamically stable dithiocarbonate molybdenum IV complex (C5Me5)Mo(?-S, ?-S'-S2CO)[N(iPr)C(Ph)N(iPr)]. Furthermore, the same methodology has beenemployed for the room temperature, catalytic synthesis of isothiocyanates from S8and the corresponding isonitriles. This process is not sensitive to the presence ofother small organic molecules, such as amines, thus providing a potentially 'greener'on-demand generation of hazardous isothiocyanates that are reactive intermediatesfor industrial production of pesticides and pharmaceuticals..

Catalytic production of carbonyl sulfide (S=C=O) and isothiocyanates (S=C=NR) under near ambient conditions via facile sulfur-atom transfer

247th National Meeting (2014)

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