Ene–yne cross-metathesis with ruthenium carbene catalysts

• Cédric Fischmeister and
• Christian Bruneau

Beilstein J. Org. Chem. 2011, 7, 156–166, doi:10.3762/bjoc.7.22

• [3] demonstrated that alkyne polymerization could be initiated directly from terminal alkynes without previous preparation of a metal carbene but via the formation of a reactive vinylidene tungsten species. Later on, the efficiency of ruthenium vinylidene precursors was also shown in olefin

• later Mori [22][23] utilized chromium alkoxycarbene to develop the first cyclizations via catalytic intramolecular enyne metathesis transformation. These initial works gave reason to postulate the interaction of metal carbene with alkyne to form a metallacyclobutene that rearranges to give a metal

• triple bonds with a metal carbene. General scheme for EYCM and side reactions. Catalytic cycle with initial interaction of a metal methylidene with the triple bond. Catalytic cycle with initial interaction of a metal alkylidene with the triple bond. Formation of 2,3-disubstituted dienes via cross