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Synfacts 2005(2): 0224-0224  
DOI: 10.1055/s-2005-916110
Metal-Catalyzed Asymmetric Synthesis and Stereoselective Reactions
© Georg Thieme Verlag Stuttgart · New York

Isospecific Cobalt Catalyst for Propylene Oxide Polymerization

Contributor(s): Hisashi Yamamoto, Matthew B. Boxer
K. L. Peretti, H. Ajiro, C. T. Cohen, E. B. Lobkovsky, G. W. Coates*
Cornell University, USA
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Publikationsverlauf

Publikationsdatum:
25. Oktober 2005 (online)

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Significance

The authors report an extremely active catalyst for the highly isotactic polymerization of propylene oxide. When the CoII(salph) precursor was reacted with air and oxidized to the active CoIII catalyst, TOF’s of 220 (h-1) were achieved when the reaction was performed at 0 °C in toluene. Raising the temperature (25 °C and 40 °C) reduced the TOF, while lowering the temperature (-20 °C) reduced the yield of polymer.