Photoinduced Copper-Promoted Decarboxylative Trifluoromethylselenolation of Aromatic Carboxylic Acids with [Me4N][SeCF3].

ABSTRACT

Visible-light-induced decarboxylative trifluoromethylselenolation of (hetero)aromatic carboxylic acids with [Me4N][SeCF3], oxidant, and catalysts afforded a variety of (hetero)aryl trifluoromethyl selenoethers in good yields. The reaction might involve a radical process, which generated (hetero)aryl radicals from the stable (hetero)aromatic carboxylic acids via oxidative decarboxylation with NFSI as the oxidant, [di-tBu-Mes-Acr-Ph][BF4] as the photocatalyst, and 1,1'-biphenyl as the cocatalyst. Both catalysts had a decisive influence on the reaction. The trifluoromethylselenolation was further promoted by the copper salts probably via Cu-mediated cross-coupling of the sensitive SeCF3 species with the in situ formed (hetero)aryl radicals. Advantages of the method include visible light irradiation, mild reaction conditions at ambient temperature, good functional group tolerance, no pre-functionalization/activation of the starting carboxylic acids, and applicability to drug molecules. This protocol is promising and synthetically useful, which overcame the limitations of the known trifluoromethylselenolation methods and represented the first decarboxylative trifluoromethylselenolation of (hetero)aromatic carboxylic acids.