Latent Ruthenium Catalysts for Ring Opening Metathesis Polymerization (ROMP)

For over two decades, the development of olefin metathesis by many research groups has yielded more stable catalysts with higher turnover frequencies and greater substrate range. Modern olefin metathesis reactions are catalyzed by well-defined complexes of transition metals, such as ruthenium, tungsten, and molybdenum. This chapter covers the recent uses of latent initiators for ring opening metathesis polymerization (ROMP) reactions. The first part of the chapter deals with two physical methods of activation: thermal and light-activated ROMP. The second part discusses chemically activated systems; that usually, either directly forms the catalytically active carbene or releases a ligand that hindered the initiation. The chapter concludes with a short section on mechanochemical activation, a rarely used method that promises great potential. Undoubtedly, the progress of ruthenium latent catalysts for ROMP has afforded exciting polymers and procedures to achieve new materials with novel properties under diverse reaction conditions.