Copper(II)‐Catalyzed Aromatization Followed by Bromination of Cyclohexenones Leading to Phenols and Bromophenols

Abstract

Conversion of substituted cyclohexenones into the corresponding phenols can be achieved using copper acetate as the catalyst in the presence of LiBr and CF3COOH under oxygen. With the use of excess LiBr, electrophilic aromatic bromination afforded the corresponding bromophenol under similar catalytic conditions.

One-pot preparation of pyrazole “turn on” and “turn off” fluorescent sensors for Zn2+ and Cd2+ directly from chalcones via in situ aromatisation

“…Copper salts are cheap, easily accessible and their ease of handling and low toxicity profile have found widespread use in organic catalysis. Cu 2+ mediated aromatisation of cyclohexanone derivatives to phenols, 27 Cu 2+ catalysed aromatisation of tetrahydrocarbazole to carbazole alkaloids 28 and the synthesis of pyrazoles via copper-catalysed relay oxidation have also been reported. 29 In summary, we screen eight transition metal as in situ oxidants with Cu 2+ based oxidants the most significant with CuCl 2 providing the best option for in situ aromatisation.…”