The Nobel Prize in Chemistry 2005 goes to Yves Chauvin, Robert H. Grubbs and Richard R. Schrock "for the develop -ment of the metathesis method in organic synthesis".

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The Nobel Prize in Chemistry 2005 goes to Yves
Chauvin, Robert H. Grubbs and Richard R. Schrock
"for the develop -ment of the metathesis method
in organic synthesis".
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Olefin Metathesis / Grubbs Reaction Olefin
Metathesis allows the exchange of substituents
between different olefins - a transalkylidenation.

Synthetically useful, high-yield procedures for
lab use include ring closure between terminal
vinyl groups, cross metathesis - the
intermolecular reaction of terminal vinyl groups
- and ring opening of strained alkenes.
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Some new homogeneous catalysts which tolerate
more functional groups and are more stable and
easy to handle.
The Schrock catalysts are more active and are
useful in the conversion of sterically demanding
substrates, while the Grubbs catalysts tolerate a
wide variety of functional groups.
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Mechanism Initiation
Catalytic Cycle
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• Ring Closing Metathesis (RCM)

The Ring-Closing Metathesis (RCM) allows
synthesis of 5- up to 30-membered cyclic alkenes.
The E/Z-selectivity depends on the ring strain.
The Ru-catalysts are usually used.
Recent Literature
R. M. Conrad, M. J. Grogan, C. R. Bertozzi, Org.
Lett., 2002, 4, 1359-1361.
B. Schmidt, Eur. J. Org. Chem., 2003, 816-819.
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Cross Metathesis The transalkylidenation of two
terminal alkenes under release of ethene,
catalyzed by ruthenium carbenoids (Grubbs
Catalyst).
Recent Literature
S. BouzBouz, R. Simmons, J. Cossy, Org. Lett.,
2004, 6, 3465-3467.
K. Grela, M. Kim, Eur. J. Org. Chem., 2003,
963-966.
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Ring Opening Metathesis (Polymerization) -
ROM(P) Strained rings may be opened by a
ruthenium carbene-catalyzed reaction with a
second alkene following the mechanism of the
Cross Metathesis. The driving force is the relief
of ring strain. In absence of excess of a second
reaction partner, polymerization occurs (ROMP)
Recent Literature
E. Arstad, A. G. M. Barrett, B. T. Hopkins, J.
Koebberling, Org. Lett., 2002, 1975-1977.
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• Reviews
• M. Schuster and S. Blechert, Angew. Chem. Int.
  Ed. Engl. 1997, 36, 2036
• R. H. Grubbs and S. Chang, Tetrahedron 1998, 54,
  4413.
• R. R. Schrock, Tetrahedron 1999, 55, 8141.
• R. R. Schrock and A. H. Hoveyda, Angew. Chem.
  Int. Ed. Engl. 2003, 42, 4592.
• A. Furstner, Angew. Chem. Int. Ed. Engl. 2000,
  39, 3012.