Bimetallic Approaches in Olefin Polymerization and Metathesis

Inspired by the unique properties and reactivities of dinuclear active sites in various biological metalloproteins, the concept of cooperative two-center or multicenter catalysis - where proximate metal ions work in concert during substrate transformation - is gaining increasing popularity. Several types of cooperativity effects, ranging from double activation of substrates to bifunctional catalysis or cascade catalysis, offer exciting prospects for promoting new reactions and for improving efficiency and selectivity in homogeneous catalytic processes. This chapter summarizes the current status of bimetallic catalysis in homogeneous olefin polymerization, which has seen an impressive development over the last decade, as well as in olefin metathesis, where truly bifunctional or synergetic systems are just starting to emerge. It is evident that there is great scope for unraveling the complex mechanisms of two- and multicenter chemistry in order to fully exploit the potential of cooperativity in these important catalytic reactions.