Olefin Metathesis: Catalyst Inhibition as a Result of Isomerization

Ring‐closing metathesis of N,N‐diallyl‐tosylamide and allyl‐N‐10‐undecenenoyl‐l‐proline by using low levels of Ru‐catalyst loading were investigated. The undesirable olefin isomerization, promoted by ruthenium species formed during the decomposition of the catalyst, was observed. The volume of isomerization products depends on the catalyst loading. Accumulation of isomers that can form inactive Fischer‐type alkylidene complexes, leads to the full inhibition of the catalytic reaction.