Bismuth-catalyzed methylation and alkylation of quinone derivatives with tert-butyl peroxybenzoate as an oxidant

A bismuth-catalyzed methylation of quinones in the presence of tert-butyl peroxybenzoate (TBPB) was developed via a radical reaction mechanism. Particularly, TBPB was used not only as an efficient oxidant, but also as a green methyl source in such transformation. Moreover, this method could also be efficiently extended to the alkylation of quinones. This reaction tolerated a series of functional groups and prepared a series of derivatives of vitamin K₃ and benzoquinone. Notably, antimalarial parvaquone was synthesized by the reaction.