Isomerization of olefins by titanocene and zirconocene alkyne complexes

Abstract

An efficient isomerization of aliphatic and cyclic olefins is achieved by using well-defined metallocene alkyne complexes as catalysts. Titanocene complexes isomerize 1-alkenes to internal alkenes under mild conditions. The titanium complex was recovered quantitatively. Cyclic olefins, e.g. cyclohexadienes, also undergo isomerization, but a competing intermolecular hydrogen transfer reaction takes place as well. This side-reaction is much more favoured for zirconocene than for titanocene complexes.