ISOMERIZATION OF OLEFINS BY TITANOCENE AND ZIRCONOCENE ALKYNE COMPLEXES

An efficient isomerization of aliphatic and cyclic olefins is achieved by using well-defined metallocene alkyne complexes as catalysts. Tita nocene complexes isomerize l-alkenes to internal alkenes under mild co nditions. The titanium complex was recovered quantitatively. Cyclic ol efins, e.g. cyclohexadienes, also undergo isomerization, but a competi ng intermolecular hydrogen transfer reaction takes place as well. This side-reaction is much more favoured for zirconocene than for titanoce ne complexes.