Partial Kinetic Resolution of Oxanorbornenes by Ring-Opening Metathesis Polymerization with a Chiral Ruthenium Initiator

We report the first kinetic resolution by ring-opening metathesis polymerization (KR-ROMP). The polymerization profile showed a solvent-dependent variation of selectivity (S) over the course of the reaction. In tetrahydrofuran and dichloromethane, the resolution selectivity increased over the course of the reaction, while in toluene the selectivity was much higher in the beginning of the reaction and decreased throughout. Evidence suggests that the change in selectivity might be attributed to the chiral secondary structure of the growing polymer chain.