Ruthenium catalysts olefin ring-closing metathesis

Greco, G.E. Nobel Ghemistry in the Laboratory Synthesis of a Ruthenium Catalyst for Ring-Closing Olefin Metathesis. /. Chem. Educ. 2007, 84,1995-1997. 

Thanks to the development of the Grubbs benzylidene catalyst (2) and other related ruthenium complexes, olefin metathesis has experienced spectacular advances over the past 10 years. The various incarnations of the reaction (acyclic diene metathesis, ring-closing metathesis, ring-opening metathesis polymerization, etc.) have now acquired first rank importance in synthesis. Clearly, the emergence of a similar, generic, efficient catalytic system for con-... 

M. Scholl, T. M. Trnka, J. P. Morgan, and R. H. Grubbs, Increased Ring Closing Metathesis Activity of Ruthenium-Based Olefin Metathesis Catalysts Coordinated with Imidazolin-2-ylidene Ligands, Tetrahedron Lett. 1999, 2247-2250. 

The activity of the catalyst systems increases as the dissociation energy of the labile ligand is reduced. The catalytic performance of these systems is comparable with Schrock s highly active yet very sensitive molybdenum system [45]. So even tetrasubstituted olefins are accessible by ring-closing metathesis using these optimized air- and moisture-stable ruthenium systems [46, 47]. 

Ring closing metathesis of dienes to cyclic olefins CO2 Ruthenium catalyst... 

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