Protonation and NMR studies on 13C-acetate enriched Ru(OAc)2(Binap). Acetate as a source of water in PC bond splitting

The PC bond splitting reaction of Ru(OAc)2(Binap), containing 13CO-enriched acetate, with 2 equiv. of triflic acid at 80 °C, has been studied. NMR spectroscopy (and specifically 13C NMR data) reveal that acetic anhydride and water are produced, thus explaining the end product, which may be thought of as developing due to water adding across the PC bond. An intermediate 10 derived from attack of acetate on a P-atom is recognised. Complex 10 is shown to contain a cyclic five-membered ring, Ru{(POC(Me)(O)} fragment which develops via acetate attack on a P-atom. Crystal structures for two Ru(OAc)2(MeOBiphep) derivatives are reported.