Oxygen-atom insertion of NHC–copper complex: The source of oxygen from N,N-dimethylformamide

• Oxygen-atom was definitely transferred from the carbonyl group of DMF.
• New transformation of NHC–Cu complexes into imidazolinones.
• Trifluoromethyl species has vital effect for this reaction.

An unprecedented protocol for oxygen-atom insertion reaction of NHC–copper complexes has been developed by employing N,N-dimethylformamide as the oxygen source, which allows the preparation of imidazolinones from carbene complexes and decodes one of the mysterious transformations of NHC–metal complexes as well.

A novel oxygen-atom insertion of NHC–copper complexes has been described using N,N-dimethylformamide as the oxygen source. It allows the preparation of various imidazolinones (3a–d) in up to 99% yield.Figure optionsDownload as PowerPoint slide