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.

Mechanism

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