AgNO3-catalyzed decarboxylative cross-coupling reaction: an approach to coenzyme Q

An efficient and general method for the synthesis of coenzyme Q compounds through the activation of the 1,4-benzoquinone Csp(2)-H bond has been developed. This C-C bond formation reaction proceeds readily in an open flask by the direct cross-coupling reaction of coenzyme Q(0) with commercially available aliphatic carboxylic acids utilizing AgNO3 as a catalyst and K2S2O8 as an oxidant in aqueous solution. This radical reaction is operationally simple and amenable to gram-scale synthesis.