Development of olefin metathesis catalyst precursors bearing nucleophilic carbene ligands

From solution calorimetric measurements involving binding of nucleophilic carbenes to a ruthenium centered organometallic system, steric and electronic properties of the carbenes were assessed. An understanding of these fundamental properties led to the development of novel olefin metathesis catalysts bearing these nucleophilic carbenes as ancillary ligands. The discovery and development of olefin metathesis active ruthenium catalysts bearing a nucleophilic carbene ancillary ligand are described.