3. Reactions that do not introduce new functions into the substrate

3.1 Isomerization

Here, we'll focus on positional isomerization of the double bond in olefins (alkenes), which is most often accompanied by cis-trans rebalancing.

Other types of isomerization, in particular rearrangements of hydrocarbon skeletons, are relatively rare in coordination catalysis. Brief mention may be made of the rearrangement of linear 1,4-dienes into branched conjugated dienes [21] and the opening of strained polycyclic compounds, such as the transformation of quadricyclene into norbornadiene [22] .