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 Csp2-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.