Richard R. Schrock:"Advances in Olefin Metathesis by Molybdenum and Tungsten Alkylidene Complexes"
Olefin metathesis was first observed in the 50s by industrial chemists in the US, with the major breakthrough coming up in 1956 by Herbert Eleuterio while working at DuPont’s petrochemical department.
More than half a century afterwards, Prof. Schrock talks to us about the latest advances in olefin metathesis, most specifically, olefin metathesis by Mo and W Alkylidene Complexes.
His talk this morning focused on the developments in olefin metathesis in the latest years. There are three generations of catalysts. The first generation of very well defined Mo and W catalysts (1987-1997), a second generation of enantioselective catalysts (1997-2007) and the most recent third generation of Mono Alkoxide Pyrrolide (MAP) olefin metathesis catalysts, in which the metal is a stereogenic centre.
MAP catalysts offer many practical advantages over previous bisalkoxide or diolate catalysts, and also address several fundamental issues for the first time. Furthermore, Mo 3rd generation catalysts are much more active than their Tungsten analogues.
Prof. Schrock’s talk showed us where we are now with different examples such as a very selective synthetic process to obtain E-olefins from Z-olefins in two steps. He also highlighted some of the main challenges for chemists nowadays: looking into trisubstituted and tetrasubstituted olefins, cross-metathesis… and he finished his talk with a cost and abundancy comparison of Mo, W and Ru, which clearly showed that the future of olefin metathesis will rely on Mo and W catalysts.