SEARCH Articles Figures Tables Allenylidene-Ruthenium Complexes as Alkene Metathesis Catalyst Precursors the First Evidence Arene Ruthenium and Osmium Derivatives as Catalyst Precursors Bis-silyl Chelate Ligand Precursor XantsilH2 and Some Ruthenium Xantsil Complexes Propargylic Ethers as Alkene Metathesis Initiator Precursors Generation of Alkenyl Alkylidene-Ruthenium Catalysts Ruthenium allenylidene precursors Ruthenium catalyst precursors Ruthenium precursor compound The Ruthenium Allenylidene Precursors