A new dirhodium tetraacetate carbenoid: Synthesis, crystal structure and catalytic application

A new dirhodium tetraacetate II involving 1,3-bis(2,6-diisopropylphenyl)-imidazol-2-ylidene I was synthesized and characterized by general spectroscopic tools in the solution state as well as single X-ray crystallographic analysis in the solid state. The catalytic activity of dirhodium tetraacetate carbenoid II was tested for the allylic oxidation, and the improved reactivity to the allylic oxidation was observed compared to that of Rh2(OAc)4. The different electrochemical properties of dirhodium tetraacetate carbenoid II and Rh2(OAc)4 were compared via cyclic voltammetry.

A dirhodium tetracarboxylate complex possessing a bulky carbene ligand (NHC) at the axial position was synthesized and characterized via NMR and X-ray crystallographic analysis. By introducing an electron rich carbene ligand, the enhanced catalytic activity of Rh2(OAc)4(NHC) for the allylic oxidation was observed.Figure optionsDownload as PowerPoint slide