Silver-Catalyzed Decarboxylative Trifluoromethylation of Aliphatic Carboxylic Acids.

The silver-catalyzed decarboxylative trifluoromethylation of aliphatic carboxylic acids is described. With AgNO as the catalyst and KSO as the oxidant, the reactions of aliphatic carboxylic acids with (bpy)Cu(CF) (bpy = 2,2'-bipyridine) and ZnMe in aqueous acetonitrile at 40 °C afford the corresponding decarboxylative trifluoromethylation products in good yield. The protocol is applicable to various primary and secondary alkyl carboxylic acids and exhibits wide functional group compatibility. Mechanistic studies reveal the intermediacy of Cu(CF)Me, which undergoes reductive elimination and subsequent oxidation to give Cu(CF) as the active species responsible for the trifluoromethylation of alkyl radicals.