Ring-opening metathesis polymerization of 3-substituted cyclooctenes initiated by group 6 alkylidene complexes

Abstract

The highly cis,head-to-tail (cis,HT) selective ring-opening metathesis polymerization of 3-substituted cyclooctenes (3-RCOE; R = methyl, hexyl, phenyl) initiated by high oxidation state M and W alkylidene complexes is described herein. W(NtBu)(CHCMe₃)(pyr)(OHMT) combined high cis,HT selectivity (>98% cis,HT) with high activity, achieving 76% conversion of 5000 equivalents of 3-HexCOE after 24 h at room temperature. The resulting cis,HT-poly(3-RCOE)s (R = Me, Hex) were isolated, characterized by ¹H and ¹³C NMR, size-exclusion chromatography, and differential scanning calorimetry, and hydrogenated to generate the corresponding saturated polymer.