Metal Catalyzed Polymerization of Cyclic Olefins

Abstract

We have been interested in polymerization of cyclic olefins using transition metal catalysts. Two important polymerization fashions have been studied, ring opening metathesis polymerization and coordination insertion polymerization.

Various kinds of transition metal complex are known to catalyze the ring opening metathesis polymerization. Among those transition metal complex, ruthenium has a great advantage of less oxophilicity. A less oxophilic nature of ruthenium allows to polymerize functionalized monomer and to utilize alcohol⁄water as reaction medium. Several examples of the polymerization of functionalized monomer are known, however, very few of the polymerization in water is known. In addition, ring opening metathesis polymerization does not involve extra reagents and production of by products. From the green chemistry stand point, the utilization of water and clean reaction has a significant meaning. We have reported the investigation of the ring opening metathesis polymerization of oxo-functionalized cyclic olefin in water medium using ruthenium salt (Chapter 2).

The polynorbornene from the coordination-insertion polymerization has great features as engineering plastics, and because of its properties many research projects of the coordination polymerization of norbornene have been done. Whereas, few examples of polymerization studies of other cyclic olefin have been reported. Among these cyclic olefins, particularly of cyclobutene derivatives have never been reported, which is because of the facile pericyclic ring opening reaction of cyclobutene during polymerization and ring opening metathesis polymerization as a side reaction. This our report is the first report that cyclobutene derivatives are polymerized without pericyclic ring opening reaction or ring opening metathesis polymerization to afford high molecular weight addition polymer (Chapter 3).