Catalyst Structure and Cis-Trans Selectivity in Ruthenium-based Olefin Metathesis

Control of olefin geometry has long proved a challenge in the field of Ru-catalyzed olefin metathesis. Through an understanding of the reaction mechanism, key factors that govern cis–trans selectivity in cross-metathesis applications are identified. These factors are illustrated in the relationship between ligand environment and cis–trans selectivity in several key metathesis catalysts. Recent efforts have culminated in the successful application of ligand-based design strategies in three families of Z-selective metathesis catalysts. The relationships between catalyst structure, stability and Z-selectivity in these systems are discussed.