HoveydaGrubbs

Hoveyda–Grubbs catalysts are a family of ruthenium-based complexes used to catalyze olefin metathesis reactions. They were developed by Amir Hoveyda and Robert Grubbs around 1999 as improvements to the Grubbs catalysts, with the aim of increasing stability and functional-group tolerance. The defining feature is a benzylidene ligand that incorporates an ortho-alkoxy substituent, which chelates to the ruthenium center and replaces one of the phosphine ligands present in earlier systems. This chelating benzylidene ligand helps stabilize the active species and contributes to practical handling.

Numerous variants exist, including first-generation and later generations, differing mainly in the supporting ligands and overall reactivity. In all cases, the core remains a ruthenium–benzylidene framework with a chelating ether, delivering high activity for a range of metathesis transformations. HG catalysts are valued for good stability and broad substrate compatibility, enabling metathesis under relatively mild conditions.

Applications of Hoveyda–Grubbs catalysts span key olefin metathesis reactions, including ring-closing metathesis (RCM), cross metathesis (CM), and ring-opening metathesis polymerization (ROMP). They have been employed in natural product synthesis, polymer chemistry, and materials science due to their tolerance of many functional groups and their general practicality in laboratory settings. The catalysts are commercially available from multiple suppliers and remain widely used in both academic and industrial contexts.