Abstract
The ring-opening metathesis polymerization of various alkylthiocyclooctenes was successfully carried out in the presence of a metallacyclic aryloxo (chloro)neopentylidenetungsten complex. The polymerization rates depend strongly on the steric crowding of the alkylthio substituent which confirms that coordination of the heteroatom to the metal is one of the important factors that govern the rate of the metathesis of this type of functionalized olefin.