Catalytic carhonylation of acetone oxime at bisoximatodiruthenium complexes: A simple access to anhydrous acetonine. Isolation and molecular structure of [Ru2(CO)5(Me2CNO)2 (Me2CNOH)]

Article abstract of DOI:10.1002/hlca.19910740311

In the presence of catalytic amounts of [Ru₂(CO) ₄(Me₂CNO)₂(Me₂CNOH)₂](1), a cetone oxime reacts with carbon monoxide to give 2,3,4,5-tetrahydro-2,2,4,4, 6-pentamethylpyrimidine ('a cetonine'), CO₂, and NH₃. The reaction proceeds presumably via carbonylation of Me₂C=NOH to the unstable intermediate Me₂C=N-OCHO which undergoes decarboxylation to give the corresponding imine Me₂C=NH. The final product is assumed to result from the cyclotrimerisation of Me₂C=NH with elimination of NH₃. Evidence for the intermediacy of the imine comes from the analogous reaction of acetophenone oxime, PhMeC=NOH, which gives the corresponding imine PhMeC=NH as a stable product. The isolation of the complex [RU₂(CO)₅(Me₂CNO)₂(Me ₂CNOH)] (2) suggests the carbonylation to take place at the bridging oximato ligand of 1.