The CuI-catalyzed transformation of 2-bromobenzoic acid (2-Br-BA) into salicylic acid (main product), benzoic acid, and diphenoic acid was studied. The reaction was monitored by UV/Vis spectroscopy, HPLC, and ESR. Up to 25 turnovers were achieved for low CuI concentrations. An intermediate was observed that was assigned to a complex between copper and a follow-up product of the aromatic acid, probably a complex with a copper-carbon σ-bond. The process is probably initiated by the formation of a d-π* complex of CuI with the aromatic ring of 2-Br-BA followed by the reaction with a second CuI ion. The effect of the addition of CH3CN or NH3 on the catalytic process is reported. Both were found to accelerate the process when present at relatively low concentrations and slow it down at higher concentrations. A side product, 2-aminobenzoate was observed in the presence of NH3.
|Number of pages||9|
|Journal||European Journal of Inorganic Chemistry|
|State||Published - 1 Jan 2002|
- Aromatic compounds
- Ullmann reaction
ASJC Scopus subject areas
- Inorganic Chemistry