Isomerizing Ethenolysis as an Efficient Strategy for Styrene Synthesis

Abstract

A shrinking chain: A bimetallic system consisting of [{Pd(μ-Br)(tBu3P)}2] and a ruthenium metathesis catalyst has been found to efficiently promote the cross-metathesis between substituted alkenes and ethylene, while continuously migrating the double bond along the alkenyl chain (see scheme). When alkenylarenes, such as the natural products eugenol, safrol, or estragol, were treated with this catalyst under an ethylene atmosphere, they were cleanly converted into the corresponding styrenes and propylene gas.