The remarkable metal-catalysed olefin metathesis reaction.

Catalytic olefin metathesis--through which pairs of C = C bonds are reorganized--transforms simple molecules to those that are complex and precious. This class of reactions has noticeably enriched chemical synthesis, which is the art of preparing scarce molecules with highly desirable properties (for example, medicinal agents or polymeric materials). Research in the past two decades has yielded structurally well-defined catalysts for olefin metathesis that are used to synthesize an array of molecules with unprecedented efficiency. Nonetheless, the full potential of olefin metathesis will be realized only when additional catalysts are discovered that are truly practical and afford exceptional selectivity for a significantly broader range of reactions.