Developing the physical organic chemistry of Fischer carbene complexes
Fischer carbene complexes have over the last 25 years become a major focus of many synthetic groups. On the other hand, until recently there have been only a few kinetic and/or thermodynamic studies of even the simplest reactions of these complexes. A number of such studies have now been carried out in my laboratory. This review summarizes the results obtained thus far and focuses on three areas: (1) thermodynamic and kinetic acidities of carbene complexes that contain an ionizable proton on the carbon adjacent to the carbene carbon; (2) mechanism and structure-reactivity relationships in the reactions of carbene complexes with nucleophiles; (3) mechanism of hydrolysis of carbene complexes with and without ionizable protons.