Silver-Catalyzed Decarboxylative Cross-coupling Radical Reaction: Direct Synthesis of Coenzyme Q Compounds

An efficient and general method for the synthesis of Coenzyme Q compounds through the activation of 1,4-benzoquinone C_sp2-H bond has been developed. This C-C bond formation reaction proceeds readily in an open flask by direct cross-coupling reaction of Coenzyme Q₀ with commercially available aliphatic carboxylic acids utilizing AgNO₃ as catalyst and K₂S₂O₈ as oxidant in aqueous solution. This radical reaction is operationally simple and amenable to gram-scale synthesis.