Ester Enolates Operate as Both Initiators and Catalysts for GTP

Ester Enolates Operate as Both Initiators and Catalysts for GTP 

In a study that in itself almost lays to rest the associative mechanism for GTP, Quirk generated an ester enolate by addition of TBA 9-methylfluo-renide to MMA and used it as a catalyst for GTP of MMA initiated by MTS at 50 °C. The conversion was quantitative, the MWD was in the 1.2 range, and the molecular weight was controlled by the ratio of MTS to monomer [6]. In similar experiments without the MTS, conversions of only 14-52% were obtained, the MWD was broad and molecular weight control was lost. 

Thus unless the rate of polymerization of MMA by complex and by bare enolate where the same (which is highly unlikely) the MWD and Mn control would be lost. 

---