Synthesis of vanadium-alkylidene complexes and their use as catalysts for ring opening metathesis polymerization.

Reported examples for synthesis of vanadium-alkylidene complexes and some selected reactions have been summarized. (Imido)vanadium(v)-alkylidene complexes exhibit catalytic activities for ring-opening metathesis polymerization (ROMP) of cyclic olefins; V(CHSiMe3)(N-2,6-Cl2C6H3)(OC6F5)(PMe3)2 exhibited remarkable catalytic activities for ROMPs of norbornene derivatives, polymerized cyclopentene and cis-cyclooctene. Highly cis-specific (living) ROMPs of norbornene have been achieved by V(CHSiMe3)(N-2,6-X2C6H3)[OC(CF3)3](PMe3)2 (X = H, Cl), and the activity increased at high temperature (50 and 80 °C) without a decrease in cis specificity (98%) in the presence of PMe3.