• (Z)-Selective Isomerization of Terminal Alkenes using an air-stable Mo(0) Complex

      Dobereiner, Graham; Temple University. Diamond Research Scholars (Temple University. Libraries, 2018)
      Terminal olefin isomerization with transition metal catalysts has emerged in the past decade as a useful means of generating regio- and stereo-selective internal alkenes. In this work, an array of previously characterized and uncharacterized molybdenum(0) phosphine complexes were synthesized and tested by their ability to catalyze olefin isomerization for a variety of reagents. When coupled with co-catalytic acid (TsOH), these catalysts—specifically the cis-Mo(CO)4(PPh3)2 complex—generally produced an excess of the higher energy (Z)-2-alkene isomer from terminal olefin substrates with state-of-the-art selectivity. Importantly, the Mo(0) complexes examined herein are air-stable, simple to produce and isolate, and demonstrate activity with low catalytic loading (0.5%) and under mild conditions (66 °C in THF). This practicality may extend their use to the organic synthesis of fine chemicals without the generation of significant reagent or solvent waste. Furthermore, the activity and unique selectivity observed with these catalysts should encourage further inquiry into other molybdenum-mediated reactions involving olefins.