Bieniek, M.; Michrowska, A.; Usanov, D. L.; Grela, K. In an Attempt to Provide a User’s Guide to the Galaxy of Benzylidene, Alkoxybenzylidene, and Indenylidene Ruthenium Olefin Metathesis Catalysts. Chem. Eur. J. 2008, 14, 806-818.
There are a number of ruthenium metathesis catalysts out there, and if you squint just enough, they all look the same. When a group discovers a new catalyst, they’ll generally compare it under a given set of conditions to some of the other catalysts out there. But these reports are fragmented in the literature and apples-to-apples comparisons can be hard to come by.
Grela and coworkers take a step toward remedying this problem by examining multiple catalysts under parallel reaction conditions. They generate a lot of data, and the overall conclusion is no one catalyst is best. Of course the Grela group couldn’t explore every set of possible temperatures, solvents, substrate/catalyst purity levels, etc., but this is an important step in knowledge-based guidance for us metathesis users as to what catalyst is best in what scenarios.