Cis-Specific Chain Transfer Ring-Opening Metathesis Polymerization Using a Vanadium(V) Alkylidene Catalyst for Efficient Synthesis of End-Functionalized Polymers

Highly efficient synthesis of end-functionalized polymers has been achieved by combined cis-specific ring-opening metathesis polymerization (ROMP) of norbornene with terminal olefins (1-hexene, allyltrimethylsilane (ATMS), etc.) as the chain transfer (cross metathesis) agent at 80 degrees C in the presence of V(CHSiMe3)(N-2,6-Cl2C6H3)[OC(CF3)(3)](PMe3)(2). The ROMP proceeds with high activity and high cis selectivity (97-98%) upon addition of PMe3, and the M-n values could be controlled by varying the concentration of terminal olefins; the activity at 80 degrees C was not affected by the ATMS concentrations (5.0-50.0 mol %, TOF 1860-1890 min(-1) ((1.12-1.13) X 10(5) h(-1))).