Flook, M. M.; Jiang, A. J.; Schrock, R. R.; Müller, P.; Hoveyda, A. H. Z-Selective olefin metathesis processes catalyzed by a molybdenum hexaisopropylterphenoxide monopyrrolide complex. J. Am. Chem. Soc. 2009, 131, 7962-7963.
There aren’t many interuniversity partnerships out there that have been more productive than the one between Richard Schrock and Amir Hoveyda. Recently, this collaboration has resulted in the development of a new type of molybdenum catalyst which contains a stereogeneic metal center. These complexes were originally developed as enantioselective metathesis catalysts (a role in which they perform very well), but recent catalyst optimization has shown some catalysts in this series to have exquisite cis selectivity.
A normal olefin metathesis catalyst would give predominantly trans product. Schrock notes that even after 3 days, the product mixture contains only ~50% of trans olefins. It’s tough to beat thermodynamics, but Schrock and Hoveyda are putting up a great fight!