Highly Active Catalysts in Alkene Metathesis : First Observed Transformation of Allenylidene into Indenylidene via Alkenylcarbyne - Ruthenium Species

Autores: Ricardo Castarlenas y Pierre H. Dixneuf Ref. revista: Angewandte Chemie International Edition, 42, 4524-4527 (2003)

The transformation of the allenylidene-ruthenium complexes [RuCl(η6-arene)(=C=C=CR2)(PR3)][CF3SO3] into indenylidene species [RuCl(η6-arene)(indenylidene)(PR3)][CF3SO3]2 by the simple protonation with CF3SO3H and formation of an alkenylcarbyne intermediate is observed by low temperature NMR experiments. The new in situ generated 18 electron ionic indenylidene species are highly active in the polymerization of cyclooctene and cyclopentene, ring-closing metathesis of dienes and enynes, and the acyclic diene metathesis of decadiene, thus making it a catalyst for all seasons.