Unprecedented Formation of μ-Vinylidene Complexes from Phospharuthenocene and Acyl Chloride via Activation of the CO Double Bond

A novel reaction mode of phosphametallocenes was discovered. The phospharuthenocenes with cyclohexyl substituents at the α-positions of the η5-phospholide(s) reacted with acyl electrophiles by an initial electrophilic attack to the ruthenium to produce the μ-alkenylidene species with activation of the acyl C═O double bond and elimination of an α-hydrogen.