Combination of vinyl, phenyl and carbonyl ligands in ruthenium(II) complexes: a route to vinyl ketones

Abstract

Conversion of chloride complexes [Ru(CO)₂(CHCHR)Cl(PMe₂Ph)₂](R = CMe₃ or Ph) into the corresponding phenyl complexes [Ru(CO)₂(CHCHR)Ph(PMe₂Ph)₂] by low-temperature treatment with LiPh is accompanied by a change in the ligand arrangement around the metal. At 20 °C the products undergo two competing rearrangement processes, one a simple isomerisation back to a ligand arrangement analogous to that in [Ru(CO)₂(CHCHR)Cl(PMe₂Ph)₂] and the other a remarkably facile combination of phenyl, carbonyl and vinyl ligands to yield the ketone complexes [Ru(CO)(η⁴-PhCOCHCHR)(PMe₂Ph)₂], from which the ketone may be liberated by treatment with Me₃CNC.