Cross metathesis (CM) is an attractive alternative to other olefination methods due to the large variety of commercially available olefin starting materials and to the high functional group tolerance of the ruthenium metathesis catalysts. Depending … [Continue reading]
Acyclic Diene Metathesis (ADMET) uses metathesis of terminal dienes to produce linear polymers and ethylene. Because ADMET is actually a variation on cross-metathesis, the process is reversible, and ethylene must be removed to drive the … [Continue reading]
Enyne metathesis is the reaction of an olefin and an alkyne to produce a 1,3-diene. When an alkyne is available to coordinate a ruthenium alkylidene, the reaction known as enyne metathesis can occur. The mechanism is analogous to an RCM … [Continue reading]
The first asymmetric Mo-based metathesis catalyst was reported by Grubbs way back in 1996 (J. Am. Chem. Soc. 1996, 118, 2499). Since then, a large number of other chiral catalysts have been developed, based both on Ru and Mo (some structures shown … [Continue reading]
Ring-opening metathesis polymerization (ROMP) uses metathesis catalysts to generate polymers from cyclic olefins. ROMP is most effective on strained cyclic olefins, because the relief of ring strain is a major driving force for the reaction – … [Continue reading]
If all goes well, I plan to write about Ring Closing Metathesis (RCM) quite a bit on this site, so I figured I needed a very broad RCM overview. Anyway, what kind of metathesis website would this be without the generic RCM scheme we’ve all seen a … [Continue reading]
The second revolution in ruthenium-catalyzed olefin metathesis was triggered by substituting one phosphine ligand in 1st generation catalysts with a more basic N-heterocyclic carbene (NHC). The activity of these 2nd generation (NHC-bearing) catalysts … [Continue reading]
Modern ruthenium based olefin catalysts encompass a range of complexes able to readily generate a 14 electron catalytic active species of the generic formula (L)(X2)Ru=CRR’ (L being a phosphine ligand in first generation catalysts). The first … [Continue reading]
What’s the Big Deal? Why do we need a whole website dedicated to olefin metathesis? Because there’s enough information out there to warrant one. And it’s a useful process. Ask any organic chemist and they’ll tell you that most of their time and … [Continue reading]
It would take all day to go into all the details (that we know so far) about the olefin metathesis reaction mechanism. There have been a number of intense experimental and computational studies on various catalyst systems, and there’s still more work … [Continue reading]
Olefin metathesis is a chemical reaction in which two carbon-carbon double bonds (olefins) come together and exchange with one another, forming new olefinic products in the process. In the simple example below, symmetrical disubstituted olefins … [Continue reading]