Grubbs catalysts are generally classified into two generations: First-Generation Grubbs Catalysts These are characterized by their simplicity and comprise a ruthenium center coordinated to a phosphine ligand and a carbene. They are effective in a variety of metathesis reactions but may require higher temperatures and longer reaction times. Second-Generation Grubbs Catalysts The second-generation catalysts feature a more complex ligand structure, often incorporating an N-heterocyclic carbene (NHC). These catalysts are more active and can operate under milder conditions, making them suitable for a broader range of substrates.
