Synthesis and activity of a new generation of ruthenium-based olefin metathesis catalysts coordinated with 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene ligands.
[formula: see text] A new family of 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene-substituted ruthenium-based complexes 9a-c has been prepared starting from RuCl2(=CHPh)(PCy3)2 2. These air- and water-tolerant complexes were shown to exhibit an increased ring-closing metathesis activity at elevated temperature when compared to that of the parent complex 2 and the previously developed complex 3. In many instances the activity of these complexes also rivaled or exceeded that of the alkoxy-imido molybdenum complex 1. Catalyst loadings of as low as 0.05 mol% could be used.
Scholl
M
M
Arnold and Mabel Beckman Laboratory of Chemical Synthesis, California Institute of Technology, Pasadena 91125, USA.
Ding
S
S
Lee
C W
CW
Grubbs
R H
RH
D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D007093:Imidazoles / Q000737:chemistry*; D008024:Ligands; D012428:Ruthenium / Q000737:chemistry*
D000475:Alkenes; D007093:Imidazoles; D008024:Ligands; D012428:Ruthenium