Expanded scope in ethylene-alkyne cross-metathesis: coordinating heteroatom functionality at the propargylic position.

The Grubbs 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene-substituted ruthenium complex 1 catalyzed ethylene−alkyne cross-metathesis and was shown to tolerate free hydroxyl groups and coordinating functionality at the propargylic and homopropargylic positions. Hindered and enantiomerically enriched 1-substituted alkynes also react efficiently under the reported conditions.