Novel η3-Vinylcarbene Complexes Derived from Ruthenium-Based Olefin Metathesis Catalysts.
Electron-rich, disubstituted alkynes react with (H2IMes)(PCy3)(Cl)2Ru:CHPh (1; H2IMes = 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene) to form phosphine-free η3-vinylcarbene complexes. An x-ray diffraction study on (H2IMes)(Cl)2Ru[η3-(CHPh)(CPh)(CPh)] (2) confirms the unusual structure. These complexes are relevant to the mechanisms of olefin metathesis and alkyne polymn. [on SciFinder(R)]