In this reaction two alkenes and are treated with a transition metal that acts as a catalyst, giving a mixture of alkenes (including Z/E isomers). This product is obtained by exchange of alkylidene groups.


In the reaction mechanism, the catalyst is formed by reaction of small amounts of the alkylidene complex with the starting alkene .


The metathesis of alkenes proceeds through a catalytic cycle, as follows:

The catalysts used in this reaction are Ruthenium or Molybdenum-alkylyldene complexes.


metathesis catalyst