Tungsten (IV) carbenes for the metathesis of olefins. Direct observation and identification of the chain carrying carbene complexes in a highly active catalyst system

Abstract

On addition of aluminium halides to the carbene complexes W(CHBu^t)(OCH₂Bu^t)₂X₂ conversion into highly active catalysts for olefin metathesis occurs; the nature of the initiating and propagating species in olefin metathesis has been identified by n.m.r. spectroscopy.